Iftikhar Hussain, Mohammad R. Thalji, Karanpal Singh, Avinash C. Mendhe, Rosaiah Rosaiah, Waqas Ul Arifeen, Chinho Park, Bingang Xu, Kaili Zhang
M5X4 MXenes represent a rapidly emerging subclass of two-dimensional layered materials distinguished by extended metallic networks, tunable interlayer spacing, and various surface terminations. These unique structural features endow them with exceptional electronic conductivity, abundant redox-active sites, and favorable hydrogen adsorption–desorption energetics, positioning them at the forefront of dual-function energy platforms, namely, ultrafast supercapacitors and highly efficient hydrogen evolution reaction (HER) catalysts. Recent progress in scalable synthesis, such as fluoride-free etching, molten-salt routes, and targeted functionalization, has expanded the compositional and structural diversity of M5X4 MXenes, enabling unprecedented electrochemical performance. This review examines synthesis strategies, structure–property correlations, and key electrochemical metrics, highlighting the capacitive behavior that spans electrical double-layer to pseudocapacitance and HER efficiencies that approach those of platinum-group catalysts. We critically evaluate challenges, including oxidative degradation, scalable production, and integration into practical devices, while proposing future pathways through advanced characterization, heterostructure engineering, and sustainable synthesis. By integrating current progress with forward-looking insights, this work lays a foundation for the design of multifunctional, scalable, and sustainable M5X4 MXene-based energy systems.
{"title":"Emerging M5X4 MXenes: From Atomic Structure to Applications","authors":"Iftikhar Hussain, Mohammad R. Thalji, Karanpal Singh, Avinash C. Mendhe, Rosaiah Rosaiah, Waqas Ul Arifeen, Chinho Park, Bingang Xu, Kaili Zhang","doi":"10.1039/d5ta09470d","DOIUrl":"https://doi.org/10.1039/d5ta09470d","url":null,"abstract":"M5X4 MXenes represent a rapidly emerging subclass of two-dimensional layered materials distinguished by extended metallic networks, tunable interlayer spacing, and various surface terminations. These unique structural features endow them with exceptional electronic conductivity, abundant redox-active sites, and favorable hydrogen adsorption–desorption energetics, positioning them at the forefront of dual-function energy platforms, namely, ultrafast supercapacitors and highly efficient hydrogen evolution reaction (HER) catalysts. Recent progress in scalable synthesis, such as fluoride-free etching, molten-salt routes, and targeted functionalization, has expanded the compositional and structural diversity of M5X4 MXenes, enabling unprecedented electrochemical performance. This review examines synthesis strategies, structure–property correlations, and key electrochemical metrics, highlighting the capacitive behavior that spans electrical double-layer to pseudocapacitance and HER efficiencies that approach those of platinum-group catalysts. We critically evaluate challenges, including oxidative degradation, scalable production, and integration into practical devices, while proposing future pathways through advanced characterization, heterostructure engineering, and sustainable synthesis. By integrating current progress with forward-looking insights, this work lays a foundation for the design of multifunctional, scalable, and sustainable M5X4 MXene-based energy systems.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"39 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sayed Ali Akbar Razavi, Zahra Sharifzadeh, Nasim Hassani, Elaheh Saleh, Mehdi Neek-Amal, Ali Morsali
By pioneering coordinative modulation in defective metal-organic frameworks (MOFs), a transformative leap in catalytic efficiency was achieved in this work, surpassing conventional vacancy-based designs. Coordinatively modulated (CM) Cu-NH2 sites are created in Cu3(BTC)2 (HKUST-1, H3BTC is 1,3,5-benzene tricarboxylic acid), via functionalization of missing carboxylate defective sites. For this, a secondary carboxylate linker is used so that one carboxylate is replaced with -NH2 groups. Structural characterizations reveal that amine groups are directly oriented toward inorganic nodes and coordinated to Cu-sites in the framework to generate CM-Cu-NH2 sites. Tritopic BTC3- linkers inside HKUST-1 were partially replaced with secondary linkers with same molecular geometry, 5-amino isophthalic acid (5-AIPA), and isophthalic acid (IPA). Coordinatively modulated frameworks with different ratios of CM-Cu-NH2 sites were applied for activation of peroxymonosulfate (PMS) as proof-of-concept reaction with complex mechanism based on Lewis acidity and redox activity. HN-50 framework (CuII2.167CuI0.833(BTC)1.123(5-AIPA)0.472), highest ratio of CM-Cu-NH2 and defective sites, achieves >99% pollutant degradation in 5 minutes via peroxymonosulfate activation—a 65-fold kinetic enhancement over HKUST-1, driven by enhanced Cu electrophilicity and electron transfer, as revealed by experimental and DFT studies. Experimental studies, as evidenced by theoretical simulations, reveal that two structural changes are observed in the presence of amines; (I) charge redistribution on CM-Cu-NH2 sites through increases in the density of positive charge on Cu atoms, and (II) improved electron transfer kinetic through electronic delocalization facilitated by the coordination environment of the CM-Cu-NH2 sites. These two structural factors are dominant for the highly efficient PMS activation by improve in MOF-PMS affinity and MOF-to-PMS electron transfer. This is the first study to synergistically integrate defect engineering with coordination modulation, redefining MOF catalyst design.
{"title":"Beyond Vacancy Defects: Creation of Coordinatively Modulated Defective Sites in HKUST-1 for Unprecedented Enhancement of Peroxymonosulfate Activation","authors":"Sayed Ali Akbar Razavi, Zahra Sharifzadeh, Nasim Hassani, Elaheh Saleh, Mehdi Neek-Amal, Ali Morsali","doi":"10.1039/d5ta09583b","DOIUrl":"https://doi.org/10.1039/d5ta09583b","url":null,"abstract":"By pioneering coordinative modulation in defective metal-organic frameworks (MOFs), a transformative leap in catalytic efficiency was achieved in this work, surpassing conventional vacancy-based designs. Coordinatively modulated (CM) Cu-NH2 sites are created in Cu3(BTC)2 (HKUST-1, H3BTC is 1,3,5-benzene tricarboxylic acid), via functionalization of missing carboxylate defective sites. For this, a secondary carboxylate linker is used so that one carboxylate is replaced with -NH2 groups. Structural characterizations reveal that amine groups are directly oriented toward inorganic nodes and coordinated to Cu-sites in the framework to generate CM-Cu-NH2 sites. Tritopic BTC3- linkers inside HKUST-1 were partially replaced with secondary linkers with same molecular geometry, 5-amino isophthalic acid (5-AIPA), and isophthalic acid (IPA). Coordinatively modulated frameworks with different ratios of CM-Cu-NH2 sites were applied for activation of peroxymonosulfate (PMS) as proof-of-concept reaction with complex mechanism based on Lewis acidity and redox activity. HN-50 framework (CuII2.167CuI0.833(BTC)1.123(5-AIPA)0.472), highest ratio of CM-Cu-NH2 and defective sites, achieves >99% pollutant degradation in 5 minutes via peroxymonosulfate activation—a 65-fold kinetic enhancement over HKUST-1, driven by enhanced Cu electrophilicity and electron transfer, as revealed by experimental and DFT studies. Experimental studies, as evidenced by theoretical simulations, reveal that two structural changes are observed in the presence of amines; (I) charge redistribution on CM-Cu-NH2 sites through increases in the density of positive charge on Cu atoms, and (II) improved electron transfer kinetic through electronic delocalization facilitated by the coordination environment of the CM-Cu-NH2 sites. These two structural factors are dominant for the highly efficient PMS activation by improve in MOF-PMS affinity and MOF-to-PMS electron transfer. This is the first study to synergistically integrate defect engineering with coordination modulation, redefining MOF catalyst design.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"48 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arpita Das, Chandrakanta Guchhait, Bimalendu Adhikari, Hui Zhou, Bidhan Kumbhakar, Xianzhi Meng, Hu Li, Samuel Lalthazuala Rokhum
The rational design of superhydrophobic solid acid catalysts with enhanced chemical stability is critical for overcoming water-induced deactivation in biodiesel synthesis. Herein, we developed a novel etherified sulfonic acid-functionalized activated biochar catalyst (ESAB@PhSO3H) for efficient conversion of non-edible feedstock, Jatropha curcas oil to biodiesel. The strategy overcomes hydrolytic instability by incorporating chemically resilient ether bonds that prevent alkyl chain detachment in an acidic environment while maintaining remarkable surface hydrophobicity with a water contact angle of 167.6°. The catalyst demonstrated a high surface area (1256 m2 g–1) and strong acid density (6.1 mmol g–1), achieving a maximal biodiesel yield of 99.2% under optimal conditions (methanol-to-oil molar ratio of 14.07:1, catalyst loading of 6.14 wt.% with respect to mass of oil, reaction temperature of 78.02 °C and time of 41.8 min) employing Response Surface Methodology based on Central Composite Design approach. In addition, ESAB@PhSO3H catalyst exhibited exceptional durability, with excellent catalytic activity (89.6 ± 0.3% biodiesel yield) even after ten cycles of reuse with negligible loss of hydrophobicity. Life Cycle Cost Analysis (LCCA) estimated the biodiesel production cost to be 0.374 USD per litre. This approach highlights the potential of such superhydrophobic acid catalysts for efficient and economically viable biodiesel production at a commercial scale.
{"title":"Highly durable superhydrophobic activated biochar catalyst for biodiesel synthesis: Process optimization and economic feasibility analysis","authors":"Arpita Das, Chandrakanta Guchhait, Bimalendu Adhikari, Hui Zhou, Bidhan Kumbhakar, Xianzhi Meng, Hu Li, Samuel Lalthazuala Rokhum","doi":"10.1039/d5ta08286b","DOIUrl":"https://doi.org/10.1039/d5ta08286b","url":null,"abstract":"The rational design of superhydrophobic solid acid catalysts with enhanced chemical stability is critical for overcoming water-induced deactivation in biodiesel synthesis. Herein, we developed a novel etherified sulfonic acid-functionalized activated biochar catalyst (ESAB@PhSO3H) for efficient conversion of non-edible feedstock, Jatropha curcas oil to biodiesel. The strategy overcomes hydrolytic instability by incorporating chemically resilient ether bonds that prevent alkyl chain detachment in an acidic environment while maintaining remarkable surface hydrophobicity with a water contact angle of 167.6°. The catalyst demonstrated a high surface area (1256 m2 g–1) and strong acid density (6.1 mmol g–1), achieving a maximal biodiesel yield of 99.2% under optimal conditions (methanol-to-oil molar ratio of 14.07:1, catalyst loading of 6.14 wt.% with respect to mass of oil, reaction temperature of 78.02 °C and time of 41.8 min) employing Response Surface Methodology based on Central Composite Design approach. In addition, ESAB@PhSO3H catalyst exhibited exceptional durability, with excellent catalytic activity (89.6 ± 0.3% biodiesel yield) even after ten cycles of reuse with negligible loss of hydrophobicity. Life Cycle Cost Analysis (LCCA) estimated the biodiesel production cost to be 0.374 USD per litre. This approach highlights the potential of such superhydrophobic acid catalysts for efficient and economically viable biodiesel production at a commercial scale.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"59 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bo Wen, Zhenyu An, Xueying Yang, Yongxin Chen, Xin Guo, Zhiliang Jin
Modifying electronic structures via vacancy engineering and elemental doping is a pivotal strategy for enhancing photocatalytic hydrogen evolution. This study investigates the creation of sulfur vacancies (Vs) in MnCdS and the incorporation of Se as a dopant. The filling of vacancy defects with Se atoms effectively enhances the photocurrent response and reduces charge transfer resistance. Subsequently, a composite catalyst featuring an S-scheme heterojunction was constructed with H-GDY, exhibiting superior photocatalytic hydrogen evolution activity. Furthermore, we corroborated the photocatalytic hydrogen evolution mechanism through Density Functional Theory (DFT), in situ X-ray photoelectron spectroscopy (in situ XPS) and Kelvin probe force microscopy (KPFM). This work provides an effective strategy for vacancy engineering and elemental doping in photocatalytic hydrogen evolution.
{"title":"Constructing an S-scheme heterojunction between defect modified MnCdS-VS/Se and H-GDY for enhanced photocatalytic hydrogen evolution","authors":"Bo Wen, Zhenyu An, Xueying Yang, Yongxin Chen, Xin Guo, Zhiliang Jin","doi":"10.1039/d5ta09662f","DOIUrl":"https://doi.org/10.1039/d5ta09662f","url":null,"abstract":"Modifying electronic structures <em>via</em> vacancy engineering and elemental doping is a pivotal strategy for enhancing photocatalytic hydrogen evolution. This study investigates the creation of sulfur vacancies (V<small><sub>s</sub></small>) in MnCdS and the incorporation of Se as a dopant. The filling of vacancy defects with Se atoms effectively enhances the photocurrent response and reduces charge transfer resistance. Subsequently, a composite catalyst featuring an S-scheme heterojunction was constructed with H-GDY, exhibiting superior photocatalytic hydrogen evolution activity. Furthermore, we corroborated the photocatalytic hydrogen evolution mechanism through Density Functional Theory (DFT), <em>in situ</em> X-ray photoelectron spectroscopy (<em>in situ</em> XPS) and Kelvin probe force microscopy (KPFM). This work provides an effective strategy for vacancy engineering and elemental doping in photocatalytic hydrogen evolution.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"25 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saurabh Kumar Kumar Sharma, Dong Zhao, Weiguang Zhu, Kun Yang, Jie Lian
Complex salt waste streams generated from chemical reprocessing of spent nuclear fuels and advanced molten salt reactor technologies require innovative materials and processes for effective immobilization and management. In this study, we report a simple, low-temperature, solution-based approach for immobilizing fluoride salts, specifically alkali halides, into metal halide perovskite (MHP) waste forms. Using NaF as a representative system, systematic experiments were conducted to immobilize alkali-halides into Na2SnF6, achieving a high fluorine content of 40.9 wt% and a fluoride loading capacity of 57.4 wt%. By tailoring key parameters such as the use of surfactants, salt grain size, and reaction temperature, the low temperature solution chemistry process achieves consistently high immobilization efficiencies above 95%. X-ray diffraction (XRD) analysis coupled with Rietveld refinement confirmed that Na2SnF6 predominantly crystallizes in the tetragonal P4₂/mnm structure as the primary phase. A hexagonal metastable phase was also observed, attributed to rapid precipitation during synthesis. Microstructural characterization using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirm uniform elemental distribution and microchemical compositions consistent with the Na₂SnF₆ crystal structure. Thermogravimetric analysis (TGA) demonstrates thermal stability of the synthesized waste forms up to 400 °C. This work establishes a foundational, cost-effective pathway for immobilizing alkali fluoride salt waste into MHP-type structures with high waste loading using novel low-temperature solution chemistry for effective management of salt waste.
{"title":"A Low Temperature Solution Chemistry Process for Fluoride Salt (NaF) Waste Immobilization into Metal Halide Perovskite Structured Na2SnF6","authors":"Saurabh Kumar Kumar Sharma, Dong Zhao, Weiguang Zhu, Kun Yang, Jie Lian","doi":"10.1039/d6ta00002a","DOIUrl":"https://doi.org/10.1039/d6ta00002a","url":null,"abstract":"Complex salt waste streams generated from chemical reprocessing of spent nuclear fuels and advanced molten salt reactor technologies require innovative materials and processes for effective immobilization and management. In this study, we report a simple, low-temperature, solution-based approach for immobilizing fluoride salts, specifically alkali halides, into metal halide perovskite (MHP) waste forms. Using NaF as a representative system, systematic experiments were conducted to immobilize alkali-halides into Na2SnF6, achieving a high fluorine content of 40.9 wt% and a fluoride loading capacity of 57.4 wt%. By tailoring key parameters such as the use of surfactants, salt grain size, and reaction temperature, the low temperature solution chemistry process achieves consistently high immobilization efficiencies above 95%. X-ray diffraction (XRD) analysis coupled with Rietveld refinement confirmed that Na2SnF6 predominantly crystallizes in the tetragonal P4₂/mnm structure as the primary phase. A hexagonal metastable phase was also observed, attributed to rapid precipitation during synthesis. Microstructural characterization using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirm uniform elemental distribution and microchemical compositions consistent with the Na₂SnF₆ crystal structure. Thermogravimetric analysis (TGA) demonstrates thermal stability of the synthesized waste forms up to 400 °C. This work establishes a foundational, cost-effective pathway for immobilizing alkali fluoride salt waste into MHP-type structures with high waste loading using novel low-temperature solution chemistry for effective management of salt waste.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"217 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The rapid evolution of low-altitude economies and intelligent transportation systems imposes stringent demands on energy storage technologies, including lightweight design, high power output, long cycle life, and intrinsic safety. Conventional lithium-ion batteries, while offering high energy density, suffer from limited power density, slow charge–discharge kinetics, and inherent thermal runaway risks, rendering them inadequate for high-dynamic applications such as electric vertical take-off and landing (eVTOL) aircraft and unmanned aerial vehicles (UAVs). In this context, micro-supercapacitors (MSCs) have emerged as a promising alternative, leveraging rapid ion adsorption/desorption and surface redox reactions to deliver exceptional power density, ultrafast charging, and prolonged cycling stability. This review systematically examines recent advancements in MSCs, with a focus on electrode material design—such as two-dimensional nanomaterials and pseudocapacitive composites—electrolyte engineering for extended voltage and temperature windows, and innovative device configurations enabled by laser processing and 3D printing. Furthermore, the integration of MSCs into structural components, control systems, and self-powered modules is discussed, highlighting their role in enabling multifunctional, conformal, and symbiotic energy systems. Finally, current challenges and future directions are outlined to guide the development of next-generation MSCs tailored for autonomous, efficient, and reliable operation in smart transportation and low-altitude aerial platforms.
{"title":"Micro-Supercapacitors for Smart Transportation and Low-Altitude Economy: Advances in Material Innovations, Device Architectures, and System Integration","authors":"Shu-Mei Ding, Qi Wang, Qi Wang, Hong-Peng Li","doi":"10.1039/d5ta09042c","DOIUrl":"https://doi.org/10.1039/d5ta09042c","url":null,"abstract":"The rapid evolution of low-altitude economies and intelligent transportation systems imposes stringent demands on energy storage technologies, including lightweight design, high power output, long cycle life, and intrinsic safety. Conventional lithium-ion batteries, while offering high energy density, suffer from limited power density, slow charge–discharge kinetics, and inherent thermal runaway risks, rendering them inadequate for high-dynamic applications such as electric vertical take-off and landing (eVTOL) aircraft and unmanned aerial vehicles (UAVs). In this context, micro-supercapacitors (MSCs) have emerged as a promising alternative, leveraging rapid ion adsorption/desorption and surface redox reactions to deliver exceptional power density, ultrafast charging, and prolonged cycling stability. This review systematically examines recent advancements in MSCs, with a focus on electrode material design—such as two-dimensional nanomaterials and pseudocapacitive composites—electrolyte engineering for extended voltage and temperature windows, and innovative device configurations enabled by laser processing and 3D printing. Furthermore, the integration of MSCs into structural components, control systems, and self-powered modules is discussed, highlighting their role in enabling multifunctional, conformal, and symbiotic energy systems. Finally, current challenges and future directions are outlined to guide the development of next-generation MSCs tailored for autonomous, efficient, and reliable operation in smart transportation and low-altitude aerial platforms.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"60 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146122366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feifei Guo, Yan Wang, Haibo Shu, Zhijie Wang, Jiaping Liu, Yun Cai, Jun Fang, Yang Yang
Manipulation on photoanode by introducing reduced TiO2 nanowire arrays with non-stoichiometric defects such as oxygen vacancies (Vo) has been verified to boost photoelectrochemical (PEC) water oxidation. The metastability of nonstoichiometric defects on the surface, however, severely limits their practical application in PEC water splitting for hydrogen production under harsh operational conditions. Here, we propose a scalable defect engineering strategy by Ti non-evaporable getter (NEG) coating on TiO2 nanowires, followed by interface reconstruction in an inert atmosphere. The Ti NEG coating under air exposure instantly forms a passivation layer on the surface, which effectively prevents deep oxidation of the underlying Ti metal film and produces Ti3+ interstitials. After thermal annealing in an anaerobic environment, the residual Ti reductive species extracts partial lattice oxygen from the TiO2 nanowire to generate an embedded transition layer filled with Vo-Ti3+ defects. This TiO2 photoanode not only retains 73%~93% of its superior initial activity after 8-hour operation across a wide pH range, but also demonstrates improved oxidation resistance against applied potentials extended to 4.5 V vs. RHE and exceptional air stability after 4-month exposure. This work provides a universal paradigm for designing durable TiO2 nanowire array photoelectrode by integrating defect engineering with surface passivation.
{"title":"Synchronously introducing and encasing non-stoichiometric defects in TiO2 nanowires by NEG coating and interface reconstruction for sustainable photoelectrochemical water oxidation","authors":"Feifei Guo, Yan Wang, Haibo Shu, Zhijie Wang, Jiaping Liu, Yun Cai, Jun Fang, Yang Yang","doi":"10.1039/d5ta08376a","DOIUrl":"https://doi.org/10.1039/d5ta08376a","url":null,"abstract":"Manipulation on photoanode by introducing reduced TiO<small><sub>2</sub></small> nanowire arrays with non-stoichiometric defects such as oxygen vacancies (V<small><sub>o</sub></small>) has been verified to boost photoelectrochemical (PEC) water oxidation. The metastability of nonstoichiometric defects on the surface, however, severely limits their practical application in PEC water splitting for hydrogen production under harsh operational conditions. Here, we propose a scalable defect engineering strategy by Ti non-evaporable getter (NEG) coating on TiO<small><sub>2</sub></small> nanowires, followed by interface reconstruction in an inert atmosphere. The Ti NEG coating under air exposure instantly forms a passivation layer on the surface, which effectively prevents deep oxidation of the underlying Ti metal film and produces Ti<small><sup>3+</sup></small> interstitials. After thermal annealing in an anaerobic environment, the residual Ti reductive species extracts partial lattice oxygen from the TiO<small><sub>2</sub></small> nanowire to generate an embedded transition layer filled with V<small><sub>o</sub></small>-Ti<small><sup>3+</sup></small> defects. This TiO<small><sub>2</sub></small> photoanode not only retains 73%~93% of its superior initial activity after 8-hour operation across a wide pH range, but also demonstrates improved oxidation resistance against applied potentials extended to 4.5 V vs. RHE and exceptional air stability after 4-month exposure. This work provides a universal paradigm for designing durable TiO<small><sub>2</sub></small> nanowire array photoelectrode by integrating defect engineering with surface passivation.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"126 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146129440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhihong Zhang, Qingbo Wang, Feifeng Wu, Jiaqaing Yang, Yi Yu, Aimin Zhang, Bin Shan
Palladium (Pd) is a highly promising catalyst for the carbon dioxide (CO₂) hydrogenation reaction, yet the mechanism by which specific transition metal dopants regulate the catalytic activity and guide the reaction selectivity of the Pd (111) crystal plane remains unresolved. This study integrates density functional theory (DFT) calculations, temperature-dependent microkinetic simulations, and the SISSO machine learning algorithm. DFT was employed to construct pure Pd (111) and eight transition-metal-doped (Ag, Co, Cu, Mn, Ni, Zn, Pt, Fe) Pd (111) models, for which the adsorption energies of intermediates, electronic structure evolution, and key reaction barriers were calculated. Microkinetic simulations were used to predict reaction rates and product selectivity, whereas SISSO was applied to identify key descriptors and construct quantitative activity models. Fe-doped Pd (111) exhibited the highest intrinsic activity at elevated temperatures, being four orders of magnitude higher than that of pure Pd at 500 K. Pt-and Cu-doped surfaces favored methanol formation, Fe-and Co-doped surfaces were biased toward formic acid production, whereas Mn-and Ni-doped surfaces exhibited over 90% CO selectivity, leading to active-site poisoning. The SISSO-derived descriptors, which incorporate adsorption energies and temperature effects, accurately reproduced the microkinetic trends (R² > 0.98, RMSE < 1.0).This integrated "DFT-microkinetics-SISSO" framework systematically maps the catalytic landscape of doped Pd (111) for CO₂ hydrogenation, elucidates dopant-regulation mechanisms, and offers a quantitative toolkit for rapid Pd-alloy screening, bridging atomic-scale insights with macroscopic catalytic performance.
{"title":"Mapping the Catalytic Landscape of Doped Pd (111) for Formic Acid Synthesis Via CO₂ Hydrogenation Using First-Principles, Microkinetics, and SISSO Descriptors","authors":"Zhihong Zhang, Qingbo Wang, Feifeng Wu, Jiaqaing Yang, Yi Yu, Aimin Zhang, Bin Shan","doi":"10.1039/d5ta09756h","DOIUrl":"https://doi.org/10.1039/d5ta09756h","url":null,"abstract":"Palladium (Pd) is a highly promising catalyst for the carbon dioxide (CO₂) hydrogenation reaction, yet the mechanism by which specific transition metal dopants regulate the catalytic activity and guide the reaction selectivity of the Pd (111) crystal plane remains unresolved. This study integrates density functional theory (DFT) calculations, temperature-dependent microkinetic simulations, and the SISSO machine learning algorithm. DFT was employed to construct pure Pd (111) and eight transition-metal-doped (Ag, Co, Cu, Mn, Ni, Zn, Pt, Fe) Pd (111) models, for which the adsorption energies of intermediates, electronic structure evolution, and key reaction barriers were calculated. Microkinetic simulations were used to predict reaction rates and product selectivity, whereas SISSO was applied to identify key descriptors and construct quantitative activity models. Fe-doped Pd (111) exhibited the highest intrinsic activity at elevated temperatures, being four orders of magnitude higher than that of pure Pd at 500 K. Pt-and Cu-doped surfaces favored methanol formation, Fe-and Co-doped surfaces were biased toward formic acid production, whereas Mn-and Ni-doped surfaces exhibited over 90% CO selectivity, leading to active-site poisoning. The SISSO-derived descriptors, which incorporate adsorption energies and temperature effects, accurately reproduced the microkinetic trends (R² > 0.98, RMSE < 1.0).This integrated \"DFT-microkinetics-SISSO\" framework systematically maps the catalytic landscape of doped Pd (111) for CO₂ hydrogenation, elucidates dopant-regulation mechanisms, and offers a quantitative toolkit for rapid Pd-alloy screening, bridging atomic-scale insights with macroscopic catalytic performance.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"244 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146139009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Donor–acceptor (D–A) conjugated microporous polymers (CMPs) have emerged as promising photocatalysts due to their tunable electronic structures and inherent porosity. However, a detailed molecular-level understanding of how specific monomeric functional groups influence photoinduced charge transfer and enhance reactive oxygen species (ROS)-driven photocatalytic processes remains limited. In this study, we propose a dual functional group modulation strategy to precisely tune the photophysical properties of CMPs for improved photocatalytic efficiency. In the first modification, the electron-withdrawing ketone group of the fluorenone-based acceptor unit in TPA-FLO is converted to an oxime, affording TPA-FLOX. Subsequently, the nitrogen atom in the triphenylamine (TPA) donor unit is replaced with a triazine moiety to yield TRZ-FLOX. Among them, TPA-FLOX exhibited an optimal band gap (2.25 eV), prolonged photoluminescence lifetime, higher oxygen adsorption energy, and enhanced charge transfer dynamics, resulting in superior photocatalytic activity. In this study, we introduced the photosynthesis of disubstituted urea from amine and carbon disulfide in one step using our heterogeneous photocatalysts. TPA-FLOX exhibits exceptional photocatalytic activity for the direct synthesis of diphenylurea from aniline, achieving 99% conversion and 97% isolated yield under visible light within 10 hours. The catalyst displays broad substrate compatibility (12 examples, 37–99% conversion) and excellent recyclability over six cycles. Beyond urea synthesis, TPA-FLOX effectively promoted the C–H thiocyanation of indoles (8 examples) and the photosynthesis of 2-benzothiazoles (12 examples), delivering isolated yields of up to 99% with wide functional group tolerance. Overall, this study demonstrates that oxime functionalization is an effective molecular design strategy for enhancing ROS-mediated photocatalysis by promoting charge separation and oxygen activation and providing a rational pathway for the development of next-generation CMP photocatalysts.
{"title":"Sequential donor–acceptor dual modulation in conjugated microporous polymers enables efficient photocatalytic synthesis of symmetric ureas, benzothiazoles and functionalized indoles","authors":"Soumitra Sau, Sibu Manna, Suman Karmakar, Sayan Roy, Bipul Mondal, Suman Joardar, Suman Kalyan Samanta","doi":"10.1039/d5ta09183g","DOIUrl":"https://doi.org/10.1039/d5ta09183g","url":null,"abstract":"Donor–acceptor (D–A) conjugated microporous polymers (CMPs) have emerged as promising photocatalysts due to their tunable electronic structures and inherent porosity. However, a detailed molecular-level understanding of how specific monomeric functional groups influence photoinduced charge transfer and enhance reactive oxygen species (ROS)-driven photocatalytic processes remains limited. In this study, we propose a dual functional group modulation strategy to precisely tune the photophysical properties of CMPs for improved photocatalytic efficiency. In the first modification, the electron-withdrawing ketone group of the fluorenone-based acceptor unit in <strong>TPA-FLO</strong> is converted to an oxime, affording <strong>TPA-FLOX</strong>. Subsequently, the nitrogen atom in the triphenylamine (TPA) donor unit is replaced with a triazine moiety to yield <strong>TRZ-FLOX</strong>. Among them, <strong>TPA-FLOX</strong> exhibited an optimal band gap (2.25 eV), prolonged photoluminescence lifetime, higher oxygen adsorption energy, and enhanced charge transfer dynamics, resulting in superior photocatalytic activity. In this study, we introduced the photosynthesis of disubstituted urea from amine and carbon disulfide in one step using our heterogeneous photocatalysts. <strong>TPA-FLOX</strong> exhibits exceptional photocatalytic activity for the direct synthesis of diphenylurea from aniline, achieving 99% conversion and 97% isolated yield under visible light within 10 hours. The catalyst displays broad substrate compatibility (12 examples, 37–99% conversion) and excellent recyclability over six cycles. Beyond urea synthesis, <strong>TPA-FLOX</strong> effectively promoted the C–H thiocyanation of indoles (8 examples) and the photosynthesis of 2-benzothiazoles (12 examples), delivering isolated yields of up to 99% with wide functional group tolerance. Overall, this study demonstrates that oxime functionalization is an effective molecular design strategy for enhancing ROS-mediated photocatalysis by promoting charge separation and oxygen activation and providing a rational pathway for the development of next-generation CMP photocatalysts.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"17 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the rapid development of the Internet of Things (IoT), there has been a significant surge in demand for flexible power supply. However, most existing solutions still face challenges in delivering both a continuous, stable energy supply and excellent mechanical adaptability.Herein, we report a Ag2Se network fabricated via a single-step electrodeposition process, which enables continuous regulation of porosity in the range of 75%-99%. This method leads to the formation of a highly interconnected porous architecture. The optimized network with 92% porosity demonstrates a synergistic enhancement of thermoelectric and mechanical properties, achieving a zT value of 0.38 and excellent strain stability, with only a 6.4% increase in resistance after 1000 compressive cycles. The single-leg device based on this material delivers a high power density of 181.5 μW cm -2 under a temperature difference of 40 K. In comparison, a denser network with 86% porosity, while mechanically rigid, achieves a room-temperature zT of 1.0, outperforming most bulk Ag2Se thermoelectric materials. This work provides an effective strategy to coordinate thermoelectric performance and mechanical flexibility through structural porosity modulation, paving the way for advanced wearable self-powered technologies.
随着物联网（IoT）的快速发展，对柔性电源的需求急剧增加。然而，大多数现有的解决方案在提供连续、稳定的能源供应和出色的机械适应性方面仍然面临挑战。在此，我们报告了通过单步电沉积工艺制备的Ag2Se网络，该网络可以在75%-99%的范围内连续调节孔隙率。这种方法导致形成高度互连的多孔结构。优化后的网络具有92%的孔隙率，表现出热电性能和力学性能的协同增强，zT值达到0.38，应变稳定性优异，1000次压缩循环后电阻仅增加6.4%。基于该材料的单脚器件在40 K的温差下可提供181.5 μW cm -2的高功率密度。相比之下，具有86%孔隙率的致密网络，虽然机械刚性，但室温zT为1.0，优于大多数块状Ag2Se热电材料。这项工作提供了一种有效的策略，通过结构孔隙率调制来协调热电性能和机械灵活性，为先进的可穿戴自供电技术铺平了道路。
{"title":"High-Performance Tailored Ag 2 Se Thermoelectric Networks via Electrodeposition for Body Heat Recovery","authors":"Liming Xiao, Fangyuan Yu, Ping Sun, Xiaodong Wang, Linmao Wen, Yunzi Ren, Feng Cao, Jun Mao, Qian Zhang","doi":"10.1039/d5ta09696k","DOIUrl":"https://doi.org/10.1039/d5ta09696k","url":null,"abstract":"With the rapid development of the Internet of Things (IoT), there has been a significant surge in demand for flexible power supply. However, most existing solutions still face challenges in delivering both a continuous, stable energy supply and excellent mechanical adaptability.Herein, we report a Ag2Se network fabricated via a single-step electrodeposition process, which enables continuous regulation of porosity in the range of 75%-99%. This method leads to the formation of a highly interconnected porous architecture. The optimized network with 92% porosity demonstrates a synergistic enhancement of thermoelectric and mechanical properties, achieving a zT value of 0.38 and excellent strain stability, with only a 6.4% increase in resistance after 1000 compressive cycles. The single-leg device based on this material delivers a high power density of 181.5 μW cm -2 under a temperature difference of 40 K. In comparison, a denser network with 86% porosity, while mechanically rigid, achieves a room-temperature zT of 1.0, outperforming most bulk Ag2Se thermoelectric materials. This work provides an effective strategy to coordinate thermoelectric performance and mechanical flexibility through structural porosity modulation, paving the way for advanced wearable self-powered technologies.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"217 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2026-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146135488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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