DSpace collection: 期刊論文

Investigation of permeate flux through DCMD module by inserting S-ribs carbon-fiber promoters with ascending and descending hydraulic widths

Tue, 10 Mar 2026 04:09:54 GMT

title: Investigation of permeate flux through DCMD module by inserting S-ribs carbon-fiber promoters with ascending and descending hydraulic widths abstract: A theoretical mass-balance model based on the resistance-in-series approach and energy conservation in one-dimensional governing equations was developed and experimentally validated to predict permeate flux and temperature distributions. The decline in permeate flux across membrane modules is attributed to increased temperature polarization resistance in a flat-plate direct contact membrane distillation (DCMD) module for pure water production. The performance of DCMD modules was further optimized by introducing S-ribs carbon-fiber turbulence promoters with ascending and descending hydraulic widths, while also accounting for the accompanying rise in energy consumption. An economic analysis was also carried out to evaluate the trade-off between permeate flux enhancement and additional power consumption for various carbon-fiber-filled modules. The implementation of S-ribs carbon-fiber turbulence promoters into the hot saline feed stream resulted in permeate flux improvements with a maximum increase of 25.85% under the descending configuration compared to the module of using the no-carbon-fiber-filled channel. Results indicated that modules with descending hydraulic widths of 5∼4∼3 mm configuration exhibited a higher ratio In/Ip = 1.3 of permeate flux improvement to a relative lower specific power consumption compared to those with uniform hydraulic widths. Furthermore, a simplified expression for the Nusselt number was developed to generalize the heat transfer coefficient and predict permeate flux in modules incorporating these carbon-fiber promoters.

Development of KIT-5 and amine-functionalized KIT-5 for CO2 absorption

Tue, 10 Mar 2026 04:09:48 GMT

title: Development of KIT-5 and amine-functionalized KIT-5 for CO2 absorption abstract: The rapid rise in carbon dioxide (CO2) levels in the atmosphere is a major cause of climate deterioration. Human activities, particularly over the past two centuries, have caused a substantial 50% increase in CO2 concentrations. This rise is directly linked to increasing the global temperatures and acid rain. CO2 capture using porous materials, such as mesoporous silica, is a promising mitigation approach because of its exceptional characteristics for instance, high pore volume, high surface area, and low cost. The KIT-5 is distinguished for its distinct 3-D, cubic structure with Fm3m symmetry. In this study, KIT-5 mesoporous silica was first synthesized via hydrothermal synthesis process and then was functionalized with Tetraethylenepentamine (TEPA) through an impregnation technique. The KIT-5 was analysed by different advanced characterization techniques i.e. X-ray Diffraction analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Surface area porosity analysis (SAP). Characterization techniques revealed that the synthesized KIT-5 exhibited distinguished mesoporous for its well-defined cubic la3d structure and well-tunable pore size. After functionalization, the TEPA_KIT-5 showed almost the similar structure as that of the KIT-5, Ultimately, the KIT-5 and the TEPA_KIT-5 were subjected to CO2 adsorption study at 3 bar pressure and room temperature. KIT-5 showed 0.49 mmol-CO2/g-adsorbent capacity and TEPA_KIT-5 showed an adsorption capacity of 0.82 mmol-CO2/g, which was 67.3% higher than that of KIT-5.

Theoretical and Experimental Studies of Permeate Fluxes in Double-Flow Direct-Contact Membrane Distillation (DCMD) Modules with Internal Recycle

Mon, 09 Mar 2026 04:06:27 GMT

title: Theoretical and Experimental Studies of Permeate Fluxes in Double-Flow Direct-Contact Membrane Distillation (DCMD) Modules with Internal Recycle

Review on Computational Fluid Dynamics (CFD) Modeling and Simulation of CO2 Adsorption

Mon, 09 Mar 2026 04:06:19 GMT

title: Review on Computational Fluid Dynamics (CFD) Modeling and Simulation of CO2 Adsorption

Plasma-Assisted UV Grafting of Thermo-Responsive Chitosan-co-PNIPAAm Hydrogels on Polypropylene Nonwovens for Antibacterial Biomedical Textiles

Mon, 09 Mar 2026 04:06:10 GMT

title: Plasma-Assisted UV Grafting of Thermo-Responsive Chitosan-co-PNIPAAm Hydrogels on Polypropylene Nonwovens for Antibacterial Biomedical Textiles abstract: Polypropylene (PP) nonwoven is widely used in biomedical textiles because of its lightweight and mechanical durability; however, its inherent hydrophobicity and chemical inertness limit further surface functionalization. In this study, a plasma-assisted UV grafting strategy was developed to fabricate thermo-responsive and antibacterial hydrogel coatings on PP nonwoven. Atmospheric-pressure plasma jet (APPJ) treatment was first employed to activate the PP nonwoven surface, followed by UV-induced graft polymerization of chitosan and N-isopropylacrylamide (NIPAAm), forming a chitosan-co-PNIPAAm hydrogel immobilized on the nonwoven substrate. Surface characterization using water contact angle measurement, Fourier transform infrared spectroscopy, and scanning electron microscopy confirmed effective plasma activation and successful hydrogel grafting. APPJ treatment significantly enhanced surface wettability, whereas subsequent UV grafting formed a continuous hydrogel on the PP nonwoven surface. The modified nonwoven exhibited distinct thermo-responsive swelling behavior in aqueous and simulated physiological environments, associated with the temperature-sensitive characteristics of the PNIPAAm component. In addition, the incorporation of chitosan imparted pronounced antibacterial activity against Escherichia coli, with inhibition zone diameters ranging from 14 to 16.5 mm, indicating high antibacterial sensitivity. Preliminary cytocompatibility evaluation further demonstrated favorable cell viability on the modified surfaces. This study demonstrates a scalable and low-temperature surface engineering approach for integrating stimuli-responsive and antibacterial hydrogel functionality into nonwoven polymer substrates, offering potential for advanced biomedical textile applications.

Intermixing of Sn3Ag0.5Cu solder balls and Sn52In solder paste for interconnection

Thu, 05 Mar 2026 04:07:13 GMT

title: Intermixing of Sn3Ag0.5Cu solder balls and Sn52In solder paste for interconnection abstract: As semiconductor technology advances, products are evolving toward higher performance and miniaturization. Moreover, global warming and climate change have considerably affected human life, making the development of low-temperature lead-free solder an important research topic. Sn3Ag0.5Cu solder balls were combined with low-temperature solder paste for energy efficiency. The process temperature was reduced by intermixing Sn3Ag0.5Cu solder balls and Sn52In solder paste. The mixed-assembly Sn3Ag0.5Cu/Sn52In solder joint was fabricated at a lower bonding temperature. This study presents an investigation of a composite solder system comprising medium–high-temperature lead-free solder Sn3Ag0.5Cu and a low-temperature lead-free solder Sn52In, which was bonded to an ENIG substrate. The microstructure and shear strength of the hybrid solder were examined. Sn52In low-temperature solder paste combined with Sn3Ag0.5Cu ball-grid-array (BGA) solder balls was used to reduce the process temperature. It enables the reflow process to occur at temperatures 155 ℃, compared to the typical 250 ℃ for standard SnAgCu solders. This reduction in temperature minimizes thermal stress on sensitive components and substrates, improving overall assembly reliability. The experimental results revealed that at 60 ℃, due to insufficient Cu content in the solder joint, heterogeneous nucleation resulted in discontinuous (Cu,Ni)6(Sn,In)5 in regions with relatively high Cu concentrations. At 80 ℃, the discontinuous (Cu,Ni)6(Sn,In)5 gradually transformed into a layered structure over time, and after 2000 h of aging, the reduction in the Cu content led to the transformation of (Cu,Ni)6(Sn,In)5 into (Ni,Cu)(Sn,In)2. At 130 ℃, after 1000 h of reaction, rapid intermetallic growth caused the surface treatment layer to fully react, resulting in failure. The ball shear test results revealed that the hybrid solder had a weak shear strength, with brittle fractures observed across all the tested samples. The shear stress decreased as a dual-layer intermetallic structure formed at the interface.

High-performance and robust 3D perovskite solar cells enabled by self-assembled amphiphilic molecules

Wed, 04 Mar 2026 04:05:49 GMT

title: High-performance and robust 3D perovskite solar cells enabled by self-assembled amphiphilic molecules abstract: In this study, the amphiphilic molecule octyltrimethylammonium bromide (OTAB) was integrated into 3D triple-cation lead mixed-halide (CsFAMA) perovskite films, forming a self-assembled layer on the perovskite surface. This modification significantly enhanced water resistance and elevated the energy band levels by forming an interfacial dipole, which effectively reduced carrier reverse recombination by blocking the diffusion of photogenerated electrons. OTAB also improved surface smoothness, film uniformity, and promoted a face-on crystal orientation. Additionally, the bromide ions in OTAB effectively passivated defects, thereby suppressing ion migration and mitigating non-radiative recombination. As a result, OTAB-based devices exhibited remarkable performance, achieving a power conversion efficiency (PCE) of 22.61 %, with a short-circuit current density (Jsc) of 25.36 mA/cm2, an open-circuit voltage (Voc) of 1.10 V, and a fill factor (FF) of 81.36 %. These devices also demonstrated exceptional stability, retaining 100 % of their initial PCE after 3312 h under 50 % relative humidity at 25 °C, and maintaining 80 % of their original efficiency (T80 lifetime) after 2160 h at 65 °C and 1310 h at 85 °C in a nitrogen atmosphere. The successful incorporation of this amphiphilic molecule paves the way for significant advancements in photovoltaic technology.

Dual bulk and surface passivation of 3D perovskite solar cells using zwitterionic molecules

Wed, 04 Mar 2026 04:05:31 GMT

title: Dual bulk and surface passivation of 3D perovskite solar cells using zwitterionic molecules abstract: Defect passivation plays a pivotal role in perovskite solar cells (PSCs), effectively mitigating non-radiative recombination and significantly enhancing their photovoltaic performance and stability. Herein, the zwitterionic molecule cocamidopropyl betaine (CAPB) was introduced into 3D triple-cation lead mixed-halide (CsFAMA) perovskite films, enabling dual bulk and surface passivation. The quaternary ammonium group in CAPB established electrostatic interactions with iodine ions in PbI2, while its carboxylate and amide C=O groups coordinated with Pb2+ ions, effectively suppressing non-radiative recombination. Devices incorporating CAPB achieved a notable maximum power conversion efficiency (PCE) of 21.47 % and demonstrated exceptional humidity resistance, retaining 98 % of their initial PCE after 4,080 h under 25 °C and 50 % relative humidity. Additionally, hydrogen bonds formed between the carboxylate C=O, amide C=O, and N-H groups in CAPB and the N-H groups of amines effectively mitigated amine volatilization at elevated temperatures. As a result, CAPB-based devices maintained 93 % and 80 % of their original PCE after 1,872 h at 65 °C and 85 °C, respectively. The successful integration of CAPB for dual bulk and surface passivation underscores its significant potential in advancing photovoltaic technologies.

Asymmetric Fluorinated Cyclopenta [2, 1‐b: 3, 4‐b'] Dithiophene‐Based Hole‐Transporting Materials for Perovskite Solar Cell

Tue, 03 Mar 2026 04:06:50 GMT

title: Asymmetric Fluorinated Cyclopenta [2, 1‐b: 3, 4‐b'] Dithiophene‐Based Hole‐Transporting Materials for Perovskite Solar Cell abstract: A series of asymmetric hole-transporting materials (HTMs) based on cyclopenta[2,1-b;3,4-b’]dithiophene cores tethered with p-methoxytriphenylamines donor units with or without incorporated fluorine atoms were rationally designed, synthesized, and employed in perovskite solar cells (PSCs). A comprehensive comparison is conducted encompassing the absorption spectra, electrochemical characteristics, thermal stability, density functional theory (DFT) calculations, hole mobility, and surface morphology, as revealed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), steady-state and time-resolved photoluminescence measurements, water contact angle analyzes, and photovoltaic parameters of the PSCs. The fluorinated HTMs, P-oF and P-mF, demonstrated enhanced hole mobility and more efficient charge extraction at the perovskite/HTM interface compared to their non-fluorinated counterpart. Consequently, PSCs employing P-oF and P-mF achieved power conversion efficiencies (PCEs) of 21.52% and 19.78%, respectively, with negligible hysteresis, outperforming devices based on P-H, which exhibited a PCE of 17.05%. Moreover, the operational stability of the device incorporating P-series as the HTM exceeded that of the PSCs employing the benchmark material of spiro-OMeTAD. The findings presented herein underscore the facile accessibility and potential of asymmetric compounds as alternative HTMs for PSCs. The results provide valuable insights and serve as a reference for the development of optimal HTMs for PSCs.

A simple and versatile degradable polymeric capsule for sustained delivery of bioactive molecules

Thu, 18 Dec 2025 04:05:40 GMT

title: A simple and versatile degradable polymeric capsule for sustained delivery of bioactive molecules abstract: Traditional fabrication methods for delivery vehicles often rely on thermal or solvent processing, which can pose challenges for heat- and solvent-sensitive bioactive molecules, such as proteins and peptides. These molecules may denature or lose their biological activity, ultimately reducing their therapeutic efficacy. This study proposed a simple and versatile biodegradable perforated capsule for sustained delivery of bioactive molecules. Poly (lactic-coglycolic acid) (PLGA) capsules with side perforations were fabricated using a compressionmolding method. Teicoplanin, mixedwith either phosphate-buffered solution, Pluronic F-127 hydrogel, or hyaluronic acid, was then filled into the core of the capsules. The in vitro release rates of teicoplanin were characterized over a 30-day period using an elution method and a high performance liquid chromatography (HPLC) assay. The experimental results demonstrated that the biodegradable perforated capsules released high concentrations of teicoplanin, exceeding the minimum inhibitory concentration (MIC), in vitro for 30 days. Furthermore, the high viscosity of the Pluronic F-127 hydrogel and hyaluronic acid prolonged the antibiotic’s release period. This novel capsule design holds significant promise for delivering active biomolecules, including drugs, proteins, and peptides, for long-term therapeutic applications.

Influence of Process Parameters on Shrinkage/ Warpage and Tensile Strength in ABS/PC Injection Overmolded Products

Thu, 18 Dec 2025 04:05:35 GMT

title: Influence of Process Parameters on Shrinkage/ Warpage and Tensile Strength in ABS/PC Injection Overmolded Products abstract: The limited esthetic appeal of conventional plastic products has led to increased consumer demand for visually enhanced alternatives. This shift has driven the growing use of over-molding and multi-component injection molding technologies, particularly in automotive applications such as rear directional light covers. However, the mechanical and dimensional properties of such components are significantly influenced by processing parameters—including melt temperature, mold temperature, injection speed, packing pressure, and cooling time—as well as the compatibility and interaction between different polymers. This study examines the influence of processing conditions on the shrinkage, warpage, and tensile strength of overlapped overmolded parts composed of Acrylonitrile Butadiene Styrene (ABS) and Polycarbonate (PC). Both neat and glass fiber-reinforced PC/ABS materials were investigated. The Taguchi method was employed to systematically evaluate the effects of process parameters on dimensional stability and mechanical performance. The findings reveal that cooling time plays a critical role in controlling shrinkage, warpage, and tensile strength. When the cooling time was increased from 4 to 12 s, the shrinkage and warpage were reduced from 7.68 to 4.35 mm, an improvement of 40% for the neat ABS/PC sample. Glass fiber-reinforced ABS/PC composites demonstrated significantly improved performance compared to neat counterparts, exhibiting reduced deformation and higher mechanical strength. The benefit of adding glass fiber to the neat polymer for reducing shrinkage and warpage was evident, as it decreased from 7.78 to 5.17 mm at a 4-s cooling rate, an improvement of 33.5%. Furthermore, a melt wash-out phenomenon was observed at the ABS gate area during PC over-molding, underscoring the importance of optimizing flow behavior in multi-material injection molding.

Investigation of the Melt-Rotation Effects on Fiber Orientation Variation and Geometrical Shrinkage in FRP Injection-Molded Parts

Thu, 18 Dec 2025 04:05:30 GMT

title: Investigation of the Melt-Rotation Effects on Fiber Orientation Variation and Geometrical Shrinkage in FRP Injection-Molded Parts abstract: The study focuses on the asymmetric shrinkage typically occurring between the upstream and downstream regions of FRP injection-molded products, a challenge that is particularly difficult to manage and improve. Specifically, two sets of four-cavity systems in one mold were utilized as the experimental platform. One set used a balanced runner (BR) system, and the other used a non-balanced runner (NBR) system. Each cavity in the fourcavity systems contained an ASTM D638 standard specimen with dimensions of 63.5 mm × 9.53 mm × 3.5 mm. Both CAE simulation and experimental methods were applied. The results show that the filling patterns from the simulation analysis closely matched those from the experimental study for both BR and NBR systems. Furthermore, by comparing the geometric shrinkage of the injected parts, significant differences were observed in the dimensional deformation in three directions (x, y, and z) between the NBR and BR systems. Specifically, at the end of the filling region (EFR), there was no noticeable difference in shrinkage along the flow direction, but the shrinkage in the cross-flow and thickness directions was reduced in the NBR system. Additionally, for the same cavity (1C) in both BR and NBR systems, the melt-rotation effect significantly reduced shrinkage in both the cross-flow and thickness directions. These findings strongly suggest that melt rotation can effectively modify the dimensional shrinkage of injection-molded parts. Moreover, fiber orientation analyses of the 1C cavity were also performed using CAE simulation for both BR and NBR systems. The results show that in the NBR system, the melt-rotation effect substantially alters the fiber orientation. Specifically, the fiber orientation tensors in the cross-flow (A22) direction exhibit a decreasing trend. It can be speculated that the melt rotation alters the flow field, which subsequently changes the fiber orientation by reducing the flow-fiber coupling effect, thereby reducing the upstream-to-downstream asymmetry in the cross-flow direction. Through in-depth analysis, it is demonstrated that the correlation between the macroscopic geometric shrinkage and the microscopic fiber orientation changes is highly consistent. Specifically, in the EFR, ΔA22 decreased by 0.0376, improving upstream/downstream shrinkage asymmetry in the cross-flow direction (Ly). Future work will investigate alternative melt-rotation designs and the optimization of model-internal parameters in FOD prediction.

Development of Dual-Functional Titanium Implant for Osseointegration and Antimicrobial Effects via Plasma Modification

Wed, 08 Oct 2025 04:05:18 GMT

title: Development of Dual-Functional Titanium Implant for Osseointegration and Antimicrobial Effects via Plasma Modification abstract: Introduction and aims: Titanium dental implants are widely used in clinical practice; however, they still face challenges such as implant loosening and infection. Recent studies focus on improving integration and infection resistance. In this study, a low-temperature plasma treatment was employed to fabricate a dual-functional modification layer on the titanium implant surface, offering a promising strategy that simultaneously promoted bone integration and effectively inhibited bacterial infection. Materials and methods: This was achieved by depositing a hexamethyldisilazane (HMDSZ) film on the surface of titanium implants and grafting a thermosensitive composite hydrogel designed as a drug delivery system. The natural cross-linker genipin was used to immobilize chlorhexidine on the implant collar (2 mm in length). Meanwhile, bone morphogenetic protein-2 was immobilized on the implant body (6 mm in length), ensuring controlled release to promote bone regeneration and provide strong antibacterial effects. Various experimental analyses were conducted to characterize the samples, including assessments of hydrophilicity, functional groups, elemental composition, and surface morphology. Validation was carried out through in vitro tests (cytotoxicity, mineralization, and antibacterial assays) and in vivo animal experiments (bone-to-implant contact and Periotest measurements). Results: Biocompatibility tests indicated that the plasma-treated surfaces did not exhibit cytotoxicity and facilitated osteoblast differentiation and osseointegration. The hydrogel effectively served as a carrier for the controlled release of growth factors and antibacterial agents, thereby boosting the osseointegration and antibacterial properties of the titanium implants. In vivo studies in swine models demonstrated superior bone integration and antibacterial efficacy compared to untreated and commercial implants within 2 weeks. Conclusion: The surface modification method proposed in this study successfully produced titanium implants with dual-functional surfaces, enhancing both osseointegration efficiency and antibacterial capability. Clinical significance: This approach enables implants to perform specific functions through the use of growth factors and antimicrobials, potentially advancing implant technology and improving clinical outcomes.

Advanced High Entropy Oxides for Seawater Splitting

Thu, 18 Sep 2025 04:06:43 GMT

title: Advanced High Entropy Oxides for Seawater Splitting abstract: The demand for renewable energy is increasing due to the consumption of primary energy as known as the fossil fuels. Water electrolysis to produce hydrogen is an ideal clean energy choice because of its high energy density and zero carbon emissions. However, fresh water, which accounts for less than 3 % of the worlds water supply is a high demand resource for people's livelihood. Seawater on the other hand, accounts for more than 70 % of the earth, making it much desirable as a source of hydrogen. For seawater to produce hydrogen, a more efficient, stable and longer-lasting catalyst would need to be developed. This would avoid chlorine evolution, a ‘competition’ reaction during oxygen evolution reaction (OER), which accelerates the corrosion process suppressing the lifespan of the catalyst. High entropy materials (HEM), a potential promising catalyst candidate, are able to reach much lower OER overpotentials and higher corrosion resistance due to their tunable electronic structures. In this work, we used a pulsed laser irradiation scanning on mixed salt solutions (PLMS) method to produce a six element, high entropy ceramic nanoparticles as an OER catalyst for efficient and stable work in seawater environments (Yang et al., 2021). The (AlCoCrFeMnNi)O high-entropy ceramic (HEC) we proposed demonstrate a great performance in the seawater environment. The onset voltage of oxygen-evolution can reach as low as to 1.47 V vs. reversible hydrogen electrode (RHE), and in terms of stability, our catalyst can operate for 1000 h under 100 mA/cm2. Furthermore, to understand the mechanism behind our (AlCoCrFeMnNi)O HEC, the in-situ X-ray absorption spectroscopy (XAS) measurement and In-situ extended X-ray absorption fine structure (EXAFS) are carried out in this work with varying applied voltages for OER. Co, Mn, and Ni identified as the active sites of OER and these three elements work intimately together, each with different reaction routes, including the adsorbate evolution mechanism (AEM) and lattice oxygen-participated mechanism (LOM). While Al, Cr, and Fe are not directly linked to the catalytic activity, they do play important roles to stabilize the high entropy structure throughout the whole reaction. Finally, a computational model was created using a 2x1x2 supercell to study various atom distributions. This study utilizes DFT calculations, geometry optimization, and electron density mapping. To highlight the influence of different atoms on bond lengths, particularly the impact of Al on structural distortion and addressing bond lengths involving Mn and Fe.

Stabilizing High-Ni Cathodes with Gradient Surface Ti-enrichment

Thu, 18 Sep 2025 04:06:39 GMT

title: Stabilizing High-Ni Cathodes with Gradient Surface Ti-enrichment abstract: High-Ni cathodes are being intensely pursued worldwide for electric vehicles and other energy-dense applications due to their high capacity and low cost. However, structural instabilities during electrochemical cycling and when subjected to thermal treatment have been the major issues hindering their practical deployment. We here report a rational design of coating-integrated-into-synthesis protocol for fabricating surface Ti-enriched LiNi0.8Mn0.1Co0.1O2 (NMC811#Ti) material. The coating to intermediates is crucial to obtain high structural ordering, both in the bulk and surface of high-Ni cathodes, and the Ti substitute has a unique tri-valence (Ti3+) in a gradient surface distribution. The simulations of projected density of states in the atomistic understanding further certify significantly enhanced stability of lattice oxygen for the NMC811 through such a Ti3+-based structure reinforcement. Consequently, the NMC811#Ti cathode delivers a high capacity up to 200 mAh g−1 at 0.1 C, along with superior stabilities during air-storage and thermal treatment (up to 297 °C at the fully charged state under differential scanning calorimetric measurements). The corresponding NMC811#Ti||graphite full cell exhibits a desired 83.6 % capacity retention after 1000 cycles at 0.5 C in a voltage range of 2.8–4.3 V. This work demonstrates a delicate surface reinforcement to stabilize high-Ni cathodes for long-life and safe lithium-ion batteries.

Electron-transfer Dynamics and Photocatalytic H2-production Activity of PbS@ Cu2S Nanocomposites

Thu, 18 Sep 2025 04:06:35 GMT

title: Electron-transfer Dynamics and Photocatalytic H2-production Activity of PbS@ Cu2S Nanocomposites abstract: Background Lead citrate is a precursor that can be prepared by recycling the spent lead paste of lead-acid batteries. Lead citrate is used to synthesize lead oxide, which can be repeatedly utilized for the lead-acid battery application. Methods We report a new application of lead citrate precursor to synthesize PbS@Cu2S nanomaterials for photocatalytic H2 production. PbS@Cu2S was prepared by microwave-assisted hydrothermal and ion-exchange processes. The electron-transfer dynamics and H2-production activity of PbS@Cu2S photocatalysts were studied. Significant findings A S-scheme heterojunction is proposed based on the results of Tauc plots, ultraviolet photoelectron spectroscopy, the electron paramagnetic resonance scavenger test, and in situ near-edge X-ray absorption fine structure (NEXAFS) analysis. Results of in situ NEXAFS reveal the transfer of photoexcited electrons from PbS to Cu2S. By loading an optimized amount of Cu2S, the carrier separation and photocatalytic activity of PbS@Cu2S photocatalysts are improved. This technology can transform the lead citrate precursor to the PbS@Cu2S photocatalyst with excellent high H2 production activity (3824 μmol g−1 h−1).

Sulfur-induced Electron Redistribution of Single Molybdenum Atoms Promotes Nitrogen Electroreduction to Ammonia

Wed, 17 Sep 2025 04:07:01 GMT

title: Sulfur-induced Electron Redistribution of Single Molybdenum Atoms Promotes Nitrogen Electroreduction to Ammonia abstract: Electrochemical nitrogen reduction reaction (NRR) is considered a sustainable approach that endows NH3 production from N2 and H2O under ambient conditions. Due to the sluggish adsorption/activation of N2 and the strong competition with the hydrogen evolution reaction, advanced NRR electrocatalysts with both high activity and selectivity are required. Herein, we demonstrate a local modulation strategy that simultaneously promotes NRR selectivity and activity on molybdenum-based single atom catalysts (SACs) by sulfur-induced electronic redistribution, delivering a NH3 yield rate of 46.6 μg·h−1·mgcat −1 and a Faradaic efficiency of 28.9% at a potential of − 0.2 V vs. RHE in 0.1 M HCl under ambient conditions. This study provides a promising strategy for synergizing the selectivity and activity of electrocatalysts toward multistep NRR. Moreover, such an atomic-level engineering strategy should be applicable to other SACs in general and may have a major impact on their use in electrocatalytic applications.

Realizing the Bifunctional Electrocatalysis via Local Charge Rearrangement of α-CrOOH-modulated Co@CoMoOx for Overall Water Splitting

Wed, 17 Sep 2025 04:06:58 GMT

title: Realizing the Bifunctional Electrocatalysis via Local Charge Rearrangement of α-CrOOH-modulated Co@CoMoOx for Overall Water Splitting abstract: Rational design of highly active, durable and cost-efficient bifunctional catalysts for electrochemical water splitting is critical for aggressive reform of energy technologies. Herein, earth-abundant transition-metal (TM) oxide-(oxy)hydroxide (Co@CoMoOx-α-CrOOH) is synthesized as overall water splitting catalyst via a facile electrodeposition approach. Detailed X-ray absorption spectra (XAS) reveal that incorporation of α-CrOOH can implicitly modulate the local coordination environment and the electronic structure of Co/Mo/Cr cations, as well as their synergistic interaction that contributes to more rapid charge-transfer kinetics and enhanced catalytic activity. The precisely designed Co@CoMoOx-α-CrOOH/NF electrode displays prominent overall water-splitting efficiency that require a cell voltage only 1.57 V to achieve 10 mA cm−2 along with remarkable stability over 24 h in alkaline solution, which is comparable to a Pt/C/ NF || IrO2/NF water-splitting device at the state of the art. This work provides a sustainable strategy to design efficient and cost-effective TM oxide-based catalysts for water-splitting application.

Enhancing the Cycle-life of Initial-anode-free Lithium-metal Batteries by Pre-lithiation in Mn-based Li-rich Spinel Cathodes

Wed, 17 Sep 2025 04:06:54 GMT

title: Enhancing the Cycle-life of Initial-anode-free Lithium-metal Batteries by Pre-lithiation in Mn-based Li-rich Spinel Cathodes abstract: Anode-free lithium metal batteries (AF-LMBs) are attracting growing attention due to the burgeoning pursuit of high energy density. However, the poor reversibility of lithium-ion plating/stripping on the Cu anode triggers multiple issues, including rapid capacity loss, active lithium loss, and short lifetime. Herein, a cathode pre-lithiation strategy combined with a fluorine-containing electrolyte is introduced to achieve long-lifetime AF-LMBs. Furthermore, contact pre-lithiation, a more advanced and convenient strategy, has been introduced to precisely control the lithiation degree by adjusting the contact time. It has been demonstrated that over-lithiated Li1.3Mn2O4 can deliver additional lithium ions during the charging process, thus exhibiting 94.4% capacity retention after 40 cycles.

Au@NiSx Yolk@Shell Nanostructures as Dual‐Functional Electrocatalysts for Concomitant Production of Value‐Added Tartronic Acid and Hydrogen Fuel

Wed, 17 Sep 2025 04:06:51 GMT

title: Au@NiSx Yolk@Shell Nanostructures as Dual‐Functional Electrocatalysts for Concomitant Production of Value‐Added Tartronic Acid and Hydrogen Fuel abstract: Efficient glycerol electrooxidation reaction (GEOR) over gold@nickel sulfide (Au@NiSx) yolk@shell nanostructures is demonstrated, achieving ≈50.4% glycerol conversion at 10 h, 92.6% selectivity toward three-carbon products, and 90.7% total Faradaic efficiency. By regulating the electrode potential, tartronic acid (TART), one of the highest value-added intermediates, can be produced with a selectivity as high as 43.1% and a yield of 45.6 µmol cm−2 h−1. A combination of ex situ microstructural analysis, operando Raman, and operando X-ray absorption measurements reveals a dynamic surface reconstruction course from Au@NiSx to Au@NiSx/NiOOH during the glycerol oxidation process. The unique reconstructed architectures featuring conductive interior NiSx components and active surface high-valence Ni3+ species account for the superior GEOR performance. Further integration of GEOR with hydrogen evolution reaction is realized by employing Au@NiSx as both anode and cathode electrocatalysts in a two-electrode configuration. Concomitantly production of TART and hydrogen fuel is accomplished. This study demonstrates that Au@NiSx not only can convert glycerol to TART with remarkable efficiency and selectivity, but also can produce hydrogen at a moderate level. The findings from this study can facilitate the development of dual-functional electrocatalysts capable of producing high-value products at both the cathode and anode sides.

Prolonged lifespan of initial-anode-free lithium-metal battery by pre-lithiation in Li-rich Li2Ni0.5Mn1.5O4 spinel cathode

Wed, 17 Sep 2025 04:06:48 GMT

title: Prolonged lifespan of initial-anode-free lithium-metal battery by pre-lithiation in Li-rich Li2Ni0.5Mn1.5O4 spinel cathode abstract: Anode-free lithium metal batteries (AF-LMBs) can deliver the maximum energy density. However, achieving AF-LMBs with a long lifespan remains challenging because of the poor reversibility of Li+ plating/stripping on the anode. Here, coupled with a fluorine-containing electrolyte, we introduce a cathode pre-lithiation strategy to extend the lifespan of AF-LMBs. The AF-LMB is constructed with Li-rich Li2Ni0.5Mn1.5O4 cathodes as a Li-ion extender; the Li2Ni0.5Mn1.5O4 can deliver a large amount of Li+ in the initial charging process to offset the continuous Li+ consumption, which benefits the cycling performance without sacrificing energy density. Moreover, the cathode pre-lithiation design has been practically and precisely regulated using engineering methods (Li-metal contact and pre-lithiation Li-biphenyl immersion). Benefiting from the highly reversible Li metal on the Cu anode and Li2Ni0.5Mn1.5O4 cathode, the further fabricated anode-free pouch cells achieve 350 W h kg−1 energy density and 97% capacity retention after 50 cycles.

Atomic Scale Synergistic Interactions Lead to Breakthrough Catalysts for Electrocatalytic Water Splitting

Wed, 17 Sep 2025 04:06:45 GMT

title: Atomic Scale Synergistic Interactions Lead to Breakthrough Catalysts for Electrocatalytic Water Splitting abstract: A breakthrough catalyst for electrocatalytic water splitting, precious-metal-free equi-molar high entropy alloy H-FeCoNiCuMo, is developed through exploring and maximizing strong synergistic interactions between atomically well-mixed constituents of H-FeCoNiCuMo over atomic scales. For overall electrolytic water splitting under severe industrial operation conditions, the H-FeCoNiCuMo//H-FeCoNiCuMo couple requires only an ultralow cell voltage of 1.627 V to deliver an ultrahigh current density of 1500 mA cm−2, and remains stable after a 100-hr continuous operation, largely outperforming a precious metal-based benchmark couple, Pt/C//IrO2, 2.038 V with 55% decay in 24 hr. A new catalytic phenomenon is discovered, two different catalytic mechanisms functioning simultaneously on different constituents of H-FeCoNiCuMo, the Volmer-Heyrovsky route on Co and Cu and Volmer-Tafel route on Ni and Mo, from which a new kinetic model is formulated to predict a new theoretical lower limit of Tafel slope of 15 mV dec−1 for hydrogen evolution reactions.

Photocatalytic Conversion of Gaseous Carbon Dioxide to Methanol on CuO/ZnO-embedded Carbohydrate Polymer Films

Wed, 17 Sep 2025 04:06:41 GMT

title: Photocatalytic Conversion of Gaseous Carbon Dioxide to Methanol on CuO/ZnO-embedded Carbohydrate Polymer Films abstract: A procedure that diminishes carbon dioxide in the atmosphere and converts it to alternative biofuels was reported. On zinc oxide (ZnO) nanoparticles synthesized in ethandiol, copper oxide (CuO) nanoclusters were deposited by femtosecond pulsed-laser irradiation. CuO-deposited ZnO was chemically bound with amine-terminated poly(amido amine) dendrimer using 3-glycidyloxypropyltrimethoxysilan, mixed with TEMPO-oxidized cellulose nanofibril, and molded to a film (CuO/ZnO-Den-TOCNF film). CuO/ZnO was also embedded in a chitosan (CS) matrix and molded to a film. Both films were used for adsorption and conversion of gaseous carbon dioxide. The amine groups in dendrimer loaded on TOCNF and in CS act as adsorption sites of carbon dioxide, and CuO/ZnO is a photocatalyst. On photocatalytic conversion, a composite film converted gaseous carbon dioxide to methanol (maximum 2.42 and 2.16 mmol/g(catalyst) on CuO/ZnO-Den-TOCNF and CuO/ZnO-CS films, respectively) and produced less acetaldehyde (0.030 and 0.037 mmol/g(catalyst), respectively) on irradiation with ultraviolet light for 6 h. The results indicate that the amine group is the vital component to adsorb carbon dioxide besides the catalyst (CuO/ZnO) for the conversion of carbon dioxide. Moreover, TOCNF and CS-based catalytic films are preferable with the objectives of easily removable systems from reaction vessels and of convenient environmentally compatible resources.

Hydrogenation Engineering of Bimetallic Ag–Cu-modified-titania Photocatalysts for Production of Hydrogen

Wed, 17 Sep 2025 04:06:38 GMT

title: Hydrogenation Engineering of Bimetallic Ag–Cu-modified-titania Photocatalysts for Production of Hydrogen abstract: The efficacy of treatment with hydrogen and Ag-Cu co-deposition on TiO2 photocatalysts has been investigated computationally and experimentally. The hydrogenated Ag-Cu with co-loaded TiO2 (H:(Ag-Cu/TiO2)) achieved a photoactivity about 110 times that of pristine TiO2, which corresponds to a rate of 1.16 mmol h−1 g−1 for hydrogen generation. Soft X-ray spectra and quantum-chemical calculations indicate that the notable promotion of photoactivity on H:(Ag-Cu/TiO2) is ascribable to the synergy between new electronic states and a lattice distortion. The soft X-ray absorption spectra (XAS) indicated that the TiO6 octahedral symmetry and the Ti 3d- orbital orientation are significantly affected by the Ag-Cu decoration and the hydrogenation treatment. The mechanisms involved in this photocatalysis were studied with soft XAS in situ, which showed that the photoexcited electrons transfer from the bimetallic Ag-Cu to the TiO2 conduction band as the photoresponse of this composite photocatalyst. The strategy of coupling hydrogenation with bimetallic Ag-Cu onto TiO2-based photocatalysis provides a facile and promising solution to other environmental and energy applications.

Metal Complex/ZnS-Modified Ni Foam as Magnetically Stirrable Photocatalysts: Roles of Redox Mediators and Carrier Dynamics Monitored by Operando Synchrotron X-ray Spectroscopy

Wed, 17 Sep 2025 04:06:35 GMT

title: Metal Complex/ZnS-Modified Ni Foam as Magnetically Stirrable Photocatalysts: Roles of Redox Mediators and Carrier Dynamics Monitored by Operando Synchrotron X-ray Spectroscopy abstract: Magnetically stirrable photocatalysts binding the ZnS-decorated Ni foam with the metal complex cocatalyst as a redox mediator and light-absorbing composition were investigated. Loading metal complex can improve light absorption, surface hydrophilicity, interfacial charge migration, and H2 production activity. The variation of the metal valences of the composite photocatalysts in an operando environment (with sacrificial agent solution) with and without light irradiation was investigated by X-ray absorption near-edge structure (XANES) spectra and Fourier-transformed extended X-ray absorption fine structure (EXAFS) spectra to monitor the charge carrier dynamics of photocatalysis and explain how the macrocyclic Cu complex (CuC) acted as a redox mediator better than the Ni complex. The smaller valence difference of copper valence in ZS/CuC for dark and light states revealed that the Cu complex facilitates a reversible electron transfer between the ZnS photocatalyst and H+. Loading the Cu complex can improve the separation of photogenerated carriers by the redox couple of complexes, leading to a significantly improved photocatalytic H2 production activity of 8150 μmol h–1 g–1. The reactants can flow through these magnetically stirrable Ni foam-based photocatalysts by magnetic-field-driven stirring, which improves the contact between photocatalysts and the sacrificial agents. The operando synchrotron provides new insights for understanding the roles of redox mediators.

Two-stage Conversion of CO2 to Methanol and Dimethyl Ether using CuO–ZnO–Al2O3/protonated Y-type Zeolite Catalysts

Wed, 17 Sep 2025 04:06:32 GMT

title: Two-stage Conversion of CO2 to Methanol and Dimethyl Ether using CuO–ZnO–Al2O3/protonated Y-type Zeolite Catalysts abstract: The CuO-ZnO-Al2O3/protonated Y-type zeolite (CZA/HYZ) catalysts were prepared via co-precipitation method and employed in a two-stage CO2 conversion process using a dual fixed–bed column at different temperatures and 50 bar. Catalytic components of CZA/HYZ were copper species that have been identified with XPS. Remarkably, the fine structures of CZA/HYZ catalysts metal atoms were confirmed with XANES and EXAFS spectra. Molecular configurations of catalytic species in CZA/HYZ catalyst simulated from the XANES/EXAFS spectra-analyzed fine structural parameters were schematically displayed. The optimal catalytic performances of CZA/HYZ (CH3OH conversion=78.0%, CH3OCH3/HCOOH selectivity=91.7%/8.3%, CH3OCH3/HCOOH yield=71.5%/6.5%) were achieved at 250 ºC. The Arrhenius equation and a pseudo-first-order/second-order model were used to evaluate the activation energies and rate constants of CH3OH and CH3OCH3 formations at various catalytic temperatures. The low activation energies (2.720 and 1.160 kJ mol−1) and Gibbs energies (3.26 and −40.00 kJ mol−1) of CH3OH and CH3OCH3 formations at 250 ºC, demonstrated that their spontaneities were remarkably improved via CZA/HYZ, respectively. The total income from a 10–ton per day (10–TPD) for a petrochemical refinery plant waste gas utility process was USD $43,557d−1, as well a payback of 3.23 years, based on cost evaluation. The proposed process provides a continuous two-step process for manufacturing high–value-added chemicals using industrial CO2 emitted and syngas.

科學神燈窺視奈米建築美學

Wed, 17 Sep 2025 04:06:29 GMT

title: 科學神燈窺視奈米建築美學 abstract: 能源短缺和環境污染是21世紀最重要的兩個議題，其中氫能及儲能材料在綠色能源產業的發展中扮演極其重要的角色。合理地設計出高功效的觸媒，並降低成本以取得氫能是長期以來一個重大課題。近年來，建構異質結構之奈米材料被視為是獲得高效能觸媒的一個關鍵想法。在過去的30年中，催化劑科學見證了同步輻射X光實驗的蓬勃發展。透過結合其他傳統的鑑定技術，能更加了深入了解異質結構奈米材料在進行催化反應中的結構變化。更重要的是，同步輻射X光技術還提供了進行各種原位測量技術，發展出一個研究反應過程的動態特性和時間關聯性的一個有力的技術平台。本文將針對近幾年快速發展的異質結構奈米能源材料，就其鑑定方法與應用在能源轉換／儲存方面進行介紹。

Highly Effective Degradation of Ibuprofen by Alkaline Metal-doped copper oxides via peroxymonosulfate activation: mechanisms, Degradation Pathway and Toxicity Assessments

Wed, 17 Sep 2025 04:06:26 GMT

title: Highly Effective Degradation of Ibuprofen by Alkaline Metal-doped copper oxides via peroxymonosulfate activation: mechanisms, Degradation Pathway and Toxicity Assessments abstract: Redox ratios of Cu2+/Cu+ and adsorbed oxygen species (Oads) have shown great activity toward radical generation by activating peroxymonosulfate (PMS). Herein, different alkaline metal oxides (CaO, MgO and BaO) and various amounts of CaO are incorporated into CuO, which could tune the main active sites of redox ratios of Cu2+/Cu+ and Oads. The results show that CaO-CuO-5% exhibits the outstanding performance of PMS activation toward ibuprofen (IBF) degradation with excellent kinetics (k = 0.812 min−1). The X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculation show that the CaO-CuO-5% has the higher electron density with superior electron transfer ability and lower PMS adsorption energy. Based on radical scavengers and electron paramagnetic resonance spectrometer (EPR), a nonradical process is proposed to play the dominant role. The degradation pathway and the corresponding toxicity of degraded intermediates with residue PMS after reaction is evaluated by LC-MS/MS and bioassay experiments, indicating the lower antagonistic influence on human hormone receptors after advanced oxidation process. Mitigation of the Cu leaching with cyclic stability can be achieved. This study provides a facile method to optimize high-performance catalysts to activate PMS and offer practical environmental applications in the remediation of emerging contaminants.

Photocatalytic Activity of B-doped Nano Graphene Oxide over Hydrogenated NiO-loaded TiO2 Nanotubes

Wed, 17 Sep 2025 04:06:23 GMT

title: Photocatalytic Activity of B-doped Nano Graphene Oxide over Hydrogenated NiO-loaded TiO2 Nanotubes abstract: A hydrogenated NiO-loaded anatase TiO2 with unique heterostructure nanotube arrays (denoted as H:(NiO/TiO2)) NTs were synthesized, followed by the attachment of boron-doped reduced nanographene oxide nanoparticles (B-nGO NPs) to form a vigorous composite photoelectrode B-nGO/H:(NiO/TiO2) NTs. The p-n junction created between p-type NiO and n-type TiO2 produces sufficient built-in electric field to facilitate the electron–hole pair separation and boost the interfacial electron transfer, subsequently a hydrogenation treatment to adjust the donor density and maximize the electron–hole separation. The microstructure characterization with synchrotron-based X-ray techniques straightened out that the created NiO oxygen vacancies can provide emptier d-orbitals to accept more photoexcited electrons. With the incorporation of B-nGO NPs, the partially replacement of C atoms of nGO by B atoms can form an electron–hole-rich configuration in the heterostructure to decrease the Fermi level, with a more rapid electron transfer toward TiO2 substrate during photocatalysis, which also confirmed by quantum-chemical calculations. The as-synthesized B-nGO/H:(NiO/TiO2) NTs exhibited a high photocurrent density (2.0 mA/cm2) and an effective photoconversion efficiency (2.07%) under simulated sunlight irradiation (AM1.5G, 100 mW/cm2). The eventuated photoconversion efficiency is 6 times enhanced with respect to the pristine TiO2, along with an impressive hydrogen evolution rate of 31 μmol/h/cm2. Moreover, the photocurrent durability test has confirmed the stability of B-nGO/H:(NiO/TiO2) electrode, with only a slight decay of <1% after continuous illumination for more than 4 h. Incident photon conversion efficiency spectra have revealed a boosted photo-response under visible light region (extended to ∼520 nm) with the synergistic attachment of NiO and B-nGO.

Platinum Nanoparticle Modulated Titania Electronic Structure Descriptors for Selective Photocatalytic CO2 Conversion

Wed, 17 Sep 2025 04:06:19 GMT

title: Platinum Nanoparticle Modulated Titania Electronic Structure Descriptors for Selective Photocatalytic CO2 Conversion abstract: Modulation of the electronic structure of TiO2 nanorod array (NR), which governs the selectivity for the photocatalytic CO2 conversion, is demonstrated by the deposition of Pt nanoparticles (NPs) with various configurations. In-situ X-ray absorption near edge structure (XANES) measurements suggest that the active sites for the photocatalytic reaction are located on the surface of TiO2 NRs, but not on the Pt NPs, because the photocharge transfer from TiO2 NRs to Pt NPs is inefficient. The t2g/eg orbital ratio and / orbital ratio of TiO2 acquired from Ti L3-edge spectra of the Pt NP/TiO2 NR photocatalysts, which are strongly influenced by the feature of the deposited Pt NPs, are respectively well-correlated to the experimental selectivity of H2 and CH4 for photocatalytic CO2 conversion as well as the density functional theory calculated adsorption energies of H atom and CO molecule on the TiO2 surface. The Pt NPs thus play a crucial role as a promoter rather than as a cocatalyst. Besides the adsorption energies of H and CO on TiO2, the t2g/eg and / ratios of Ti 3d unoccupied state can be the electronic structure-based descriptors of TiO2 heterostructures for photocatalytic CO2 conversion to distinguish between H2 evolution and CH4 formation.

Unveiling the Evolution of LiCoO2 beyond 4.6 V

Wed, 17 Sep 2025 04:06:16 GMT

title: Unveiling the Evolution of LiCoO2 beyond 4.6 V abstract: The working mechanism of LiCoO2 beyond 4.6 V presents complicated issues: (1) the ambiguous multistructural evolutions, (2) the vague O-related anionic redox reactions (ARR) triggered by the overlap Co–O bands, and (3) the serious electrode–electrolyte interface stability challenges. The intricate relationship among them turns into a classic “chicken and egg” conundrum, leading to a confusing evolution process of LiCoO2. Herein, from an ingenious perspective combining stacking faults and nonhomogeneous delithiation, we originally demonstrate a series of intergrowth phase evolutions from O3 to O1, passing through the so-called H1-3 phase. Moreover, in sharp contrast to the O–O dimer formed in a traditional Li-rich layered cathode, a moderate and stable arrangement of oxidized lattice oxygen is unveiled as a manifestation of ARR in LiCoO2. Additionally, we clarify the nature that dehydrogenation and hydrolysis of electrolyte trigger the chain decompositions and intensify the surface degradation.

Self-Adaptive Dual-Site Synergy with an Optimized Electronic Configuration for Overall Water Splitting in Acidic Media

Wed, 17 Sep 2025 04:06:12 GMT

title: Self-Adaptive Dual-Site Synergy with an Optimized Electronic Configuration for Overall Water Splitting in Acidic Media abstract: In harsh acidic environments, there remains a demand for catalysts that possess both high activity and stability, enabling them to efficiently enhance the slow kinetics of the hydrogen evolution reaction and oxygen evolution reaction, which are crucial for the advancement of proton exchange membrane water electrolyzers. Herein, a bifunctional electrocatalyst was designed by synergistically modulating the electronic and coordination properties. The IrOx/MnOx catalyst was successfully created, surpassing the activity and stability limitations of IrO2 catalysts for acidic overall water splitting, thereby pushing the boundaries of electrocatalytic performance. When used as both electrodes in an overall water-splitting cell, the IrOx/MnOx catalyst achieved a current density of 10 mA cm–2 at 1.51 V for 36 h without any noticeable degradation, which greatly outperformed the commercial couples (Pt/C||IrO2, 1.65 V) in acidic media. Of greater significance, X-ray absorption spectroscopy deciphered that the unsaturated Ir centers, which have an electron-rich nature, can lower energy barriers associated with the proton adsorption and desorption and oxygenated reactant species through a self-adaptive surface reconstruction process. This work introduces an approach to boost the intrinsic performance of catalysts for overall water splitting by constructing unsaturated coordination centers, offering a promising strategy for catalyst design.

Construction of dual Z-scheme Ag3VO4-BiVO4/InVO4 photocatalysts using vanadium source from spent catalysts for contaminated water treatment and bacterial inactivation

Wed, 17 Sep 2025 04:06:09 GMT

title: Construction of dual Z-scheme Ag3VO4-BiVO4/InVO4 photocatalysts using vanadium source from spent catalysts for contaminated water treatment and bacterial inactivation abstract: Vanadate-based photocatalysts have recently attracted substantial attention owing to their outstanding photocatalytic activity for degrading organic pollutants and generating energy via photocatalytic processes. However, the relatively high price of vanadium has hindered the development of vanadate-based photocatalysts for various applications. Spent catalysts obtained from oil refineries typically contain a significant quantity of vanadium, making them valuable for recovery and utilization as precursors for the production of high-value-added photocatalysts. In this study, we transformed the V present in spent catalysts produced by the petrochemical industry into ternary vanadate-based photocatalysts [BiVO4/InVO4/Ag3VO4 (BVO/IVO/AVO, respectively)] designed for water remediation. The ternary composites revealed an enhanced photocatalytic capability, which was 1.42 and 5.1 times higher than those of the binary BVO/IVO and pristine AVO due to the facilitated charge separation. The ternary photocatalysts not only effectively treated wastewater containing various organic dyes, such as methylene blue (MB), rhodamine 6G (R6G), and brilliant green (BG), but also exhibited remarkable photocatalytic performance in the degradation of antibiotics, reduction of Cr(VI), and bacterial inactivation. This paper proposes a feasible route for recycling industrial waste as a source of vanadium to produce highly efficient vanadate-based photocatalysts.

Sulfur-induced Electronic Optimization of Mo5N6 for Hydrogen Evolution through Topochemical Substitution

Wed, 17 Sep 2025 04:06:01 GMT

title: Sulfur-induced Electronic Optimization of Mo5N6 for Hydrogen Evolution through Topochemical Substitution abstract: Nitrogen-rich transition metal nitrides (e.g., Mo5N6) have emerged as promising catalysts for the hydrogen evolution reaction (HER) owing to their unique electronic properties and structural stability. However, the higher valence of metal atoms with strong hydrogen adsorption blocks the subsequent desorption process, leading to unsatisfactory HER activity. In this study, we devise a topochemical route for the synthesis of sulfur-doped Mo5N6 through the controlled ammoniation of MoS2. Experiments and density functional theory simulations reveal that the sulfur dopants reform the localized configurations of Mo5N6, thereby inducing the electron redistribution and optimizing the hydrogen adsorption energy on the basal plane. Consequently, extraordinary HER performance with an overpotential of 56 mV at 10 mA cm−2 and a Tafel slope of 37.9 mV dec-1 are achieved, outperforming most reported Mo nitride-based electrocatalysts. This work provides a feasible strategy to explore efficient electrocatalysts by electronic structure refinement using heteroatom dopants.

Environment-Dependent Structural Evolution and Electrocatalytic Performance in N2 Reduction of Mo-Based ZIF-8

Wed, 17 Sep 2025 04:05:58 GMT

title: Environment-Dependent Structural Evolution and Electrocatalytic Performance in N2 Reduction of Mo-Based ZIF-8 abstract: In this study, we used in situ transmission electron microscopy to probe the structural evolution of Mo-based zeolite imidazole framework-8 (Mo-ZIF-8) under various gaseous environments. Upon pyrolyzing Mo-ZIF-8 under oxidative, inactive, and reductive environments, the formation of Mo-related materials, including Mo2C, Mo nanoparticles, Mo nanoclusters, and Mo single atoms (Mo-SAs), is well-controlled to be anchored on the porous N-doped carbon (PNC), and the evolution mechanisms are clearly provided. Furthermore, we discussed the performance of the Mo-related materials/PNC for the electrochemical nitrogen reduction reaction (NRR). Mo-SA/PNC achieves a maximum NH3 yield rate of 15.34 μg h–1 mg–1 and a Faradic efficiency of 24.03% for NRR at a potential of −0.2 V versus reversible hydrogen electrode. Our findings suggest guidelines for the rational design of the derivatives of metal-based metal–organic frameworks and their feasible application.

XANES/EXAFS and Quantum Chemical Study of the Speciation of Arsenic in the Condensate Formed in Landfill Gas Processing: Evidence of the Dominance of As-S Species

Wed, 17 Sep 2025 04:05:54 GMT

title: XANES/EXAFS and Quantum Chemical Study of the Speciation of Arsenic in the Condensate Formed in Landfill Gas Processing: Evidence of the Dominance of As-S Species abstract: The XANES/EXAFS data and quantum chemical simulations presented in this study demonstrate several features of the chemistry of arsenic compounds found in the condensates and solids generated in landfill gas (LFG) processing carried out for renewable natural gas (RNG) production. The XANES data show the decrease in the position of the absorption edge of As atoms, similar to that characteristic for sulfur-containing As solutes and solids. The EXAFS data show that the As-O and As-S distances in these matrixes are similar to those in thioarsenates. Quantum-chemical calculations demonstrated the close agreement between the experimental and modeled As-S and As-O distances determined for a range of methylated and thiolated arsenic solutes. These calculations also showed that the increase of the number of the As-S bonds in the coordination shell of arsenic is accompanied by a consistent decrease of the charges of As atoms. This decrease is correlated with the number of the As-S bonds, in agreement with the trend observed in the XANES data. These results provide insight into the intrinsic chemistry and reactivity of As species present in LFG matrixes; they may be helpful for the development of treatment methods to control arsenic in these systems.

Zhang-Rice Singlets State Formed by Two-step Oxidation for Triggering Water Oxidation under Operando Conditions

Wed, 17 Sep 2025 04:05:45 GMT

title: Zhang-Rice Singlets State Formed by Two-step Oxidation for Triggering Water Oxidation under Operando Conditions abstract: The production of ecologically compatible fuels by electrochemical water splitting is highly desirable for modern industry. The Zhang-Rice singlet is well known for the superconductivity of high-temperature superconductors cuprate, but is rarely known for an electrochemical catalyst. Herein, we observe two steps of surface reconstruction from initial catalytic inactive Cu1+ in hydrogen treated Cu2O to Cu2+ state and further to catalytic active Zhang-Rice singlet state during the oxygen evolution reaction for water splitting. The hydrogen treated Cu2O catalyst exhibits a superior catalytic activity and stability for water splitting and is an efficient rival of other 3d-transition-metal catalysts. Multiple operando spectroscopies indicate that Zhang-Rice singlet is real active species, since it appears only under oxygen evolution reaction condition. This work provides an insight in developing an electrochemical catalyst from catalytically inactive materials and improves understanding of the mechanism of a Cu-based catalyst for water oxidation.

Direct synthesis of CH3OH from CO2 hydrogenation over Ni5Ga3/SiO2 catalysts

Wed, 17 Sep 2025 04:05:40 GMT

title: Direct synthesis of CH3OH from CO2 hydrogenation over Ni5Ga3/SiO2 catalysts abstract: Ni5Ga3/SiO2 catalysts were synthesized by co-precipitation method. The catalytic components of Ni5Ga3/SiO2 were gallium species, which was confirmed by X–ray photoelectron spectroscopy (XPS) measurements. Notably, the fine structures of the metal atoms in Ni5Ga3/SiO2 were obtained using X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The optimal catalytic performances of Ni5Ga3/SiO2 (CO2 conversion = 100.0 %, CH3OH selectivity = 84.7 %, CH3OH yield = 84.7 %) were obtained at 250 °C. At 250 °C, the low activation energies and Gibbs energies of formation for CH3OH (Ea = 42.604 kJ mol−1, = 3.26 kJ mol−1) revealed that their spontaneities were significantly enhanced by catalysts. Cost assessment of a 10-TPD (ton per day) waste gas utility process for a petrochemical refinery plant shown that the overall income was USD$88,932/d with a payback of 1.86 years. This work provides a serial route to produce high-value-added chemicals in large scale from industrial emitted CO2 and syngas utility.

Extra Storage Capacity Enabled by Structural Defects in Pseudocapacitive NbN Monocrystals for High‐Energy Hybrid Supercapacitors

Tue, 16 Sep 2025 04:06:16 GMT

title: Extra Storage Capacity Enabled by Structural Defects in Pseudocapacitive NbN Monocrystals for High‐Energy Hybrid Supercapacitors abstract: Li-ion hybrid supercapacitors (LHSCs) are intensely studied due to their favorable power densities. However, combined higher energy density materials, particularly anodes, are desirably sought. Herein, a defect-dominating structure protocol is reported. Specifically, two visible structural defects, i.e., crystal vacancy and lattice distortion have been introduced in situ in ultrafine niobium nitride (NbN) monocrystals that are integrated into a carbon (C) framework. Highly reversible Li-ion storage capacities up to 540 mAh g−1 are demonstrated in such a NbN@C composite anode, together with excellent rate capability and cycling stability. An extra vacancy-induced capacity contribution of the defective NbN component is evidenced by first-principles density functional theory (DFT) simulations in contrast to perfect modeling. Coupling with an activated carbon (AC) cathode, the NbN@C//AC cell can deliver balanced energy and power densities of 53.8 Wh kg−1 and 7818 W kg−1 at 4 A g−1, and retain a desired energy density of 56.1 Wh kg−1 after 10 000 cycles at 1 A g−1. Findings from this study, particularly the demonstrated defects-induced extra capacity of pseudocapacitive materials, may inspire new structural material designs of LHSCs.

Electron Transfer dynamics and enhanced H2 production activity of Hydrangea-like BiOBr/Bi2S3-based Photocatalysts with Cu-complex As a Redox Mediator

Tue, 16 Sep 2025 04:06:13 GMT

title: Electron Transfer dynamics and enhanced H2 production activity of Hydrangea-like BiOBr/Bi2S3-based Photocatalysts with Cu-complex As a Redox Mediator abstract: A composite photocatalyst consisting of the BiOBr/Bi2S3 heterojunction and a Cu complex exhibited high H2 production activity through an efficient transport of charge by redox couple Cu(II)/Cu(I) of the complex. BiOBr was prepared by a microwave solvothermal method. Then, the BiOBr/Bi2S3 composite was prepared as a heterojunction photocatalyst by an ion-exchange process. The copper complex was then introduced as a co-catalyst or a redox mediator. The morphology, crystal properties, optical properties, surface chemistry, photocurrent response, and photocatalytic activity of these BiOBr/Bi2S3/copper complex composites were investigated. The formation of a BiOBr/Bi2S3 heterojunction and the introduction of Cu complex improved the performance of the photocatalysts. For the first time, operando X-ray absorption spectra were recorded in situ to unveil the local interaction at the reactant-photocatalyst interface toward the photocatalysis reaction of BiOBr/Bi2S3-Cu complex photocatalyst in the sacrificial agent solution (Na2S, Na2SO3).