In this study, we report Prussian blue analog (PBA)-derived vanadium-doped cobalt-iron layered double hydroxide (V-CoFe-LDH) nanosheets as an efficient electrocatalyst for hydrazine oxidation reaction (HzOR) in the aqueous medium. The PBA–derived V-CoFe-LDH offered high surface area, large porosity, coordination unsaturation, and produced 2D nanosheets. V-CoFe-LDH exhibited superior HzOR activity, achieving a significant reduction of the potential requirement (by 0.70 V in 3-electrode and 0.42 V in 2-electrode systems) compared to anodic oxygen evolution reaction (OER). The introduction of V into CoFe-LDH structure modified the electronic properties of the catalyst, offering facile access to the higher oxidation states of Coand Fe-ions toimprove the catalytic performance. Moreover, the structural modification in PBA-derived V-CoFe-LDH led to an improved HzOR compared to the hydrothermally prepared V-CoFe-LDH-HT.
{"title":"Hydrazine oxidation-assisted electrocatalytic water splitting with Prussian blue analog-derived V-doped CoFe-layered double hydroxide nanosheets","authors":"Baghendra Singh, Toufik Ansari, Arindam Indra","doi":"10.1039/d5ta02480c","DOIUrl":"https://doi.org/10.1039/d5ta02480c","url":null,"abstract":"In this study, we report Prussian blue analog (PBA)-derived vanadium-doped cobalt-iron layered double hydroxide (V-CoFe-LDH) nanosheets as an efficient electrocatalyst for hydrazine oxidation reaction (HzOR) in the aqueous medium. The PBA–derived V-CoFe-LDH offered high surface area, large porosity, coordination unsaturation, and produced 2D nanosheets. V-CoFe-LDH exhibited superior HzOR activity, achieving a significant reduction of the potential requirement (by 0.70 V in 3-electrode and 0.42 V in 2-electrode systems) compared to anodic oxygen evolution reaction (OER). The introduction of V into CoFe-LDH structure modified the electronic properties of the catalyst, offering facile access to the higher oxidation states of Coand Fe-ions toimprove the catalytic performance. Moreover, the structural modification in PBA-derived V-CoFe-LDH led to an improved HzOR compared to the hydrothermally prepared V-CoFe-LDH-HT.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"238 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335199","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}
Vapor-deposited perovskites offer excellent reproducibility and scalability, making them highly promising for commercialization. However, limited understanding of the compositional and structural characteristics of their films hinders further improvements in crystal quality and device performance. In this work, we reveal an inherent stoichiometric gradient imbalance in vapor-solid reaction perovskite films, arising from a diffusion-limited top-down crystallization process. To address this issue, we propose a Stoichiometric Gradient Rebalancing (SGR) strategy, which involves the vapor deposition of PbI2 and PbCl2 in precise ratios followed by a re-reaction step. This simple yet effective approach homogenizes the vertical composition, reduces trap density, and enhances crystal quality. As a result, a power conversion efficiency (PCE) of 22.45% is achieved in small-area devices (0.148 cm2) and 19.92% in mini-modules (5 × 5 cm2). Moreover, the devices retain over 80% of their initial efficiency after 500 hours of continuous operation at the maximum power point. This work provides a viable strategy for improving the crystal quality of vapor-deposited perovskites and deepens the understanding of their crystallization, offering valuable insights for future advancements in vapor-deposited perovskites.
{"title":"Stoichiometric Gradient Rebalancing Achieves Surface Reconstruction and Bulk Homogenization in High-Performance Vapor-deposited Perovskite Solar Cells†","authors":"Changyu Duan, Yichen Dou, Shenghan Hu, Xinyu Deng, Meichen Liu, Mengjun Liu, Guijie Liang, Yong Peng, Yi-Bing Cheng, Zhiliang Ku","doi":"10.1039/d5ta03102h","DOIUrl":"https://doi.org/10.1039/d5ta03102h","url":null,"abstract":"Vapor-deposited perovskites offer excellent reproducibility and scalability, making them highly promising for commercialization. However, limited understanding of the compositional and structural characteristics of their films hinders further improvements in crystal quality and device performance. In this work, we reveal an inherent stoichiometric gradient imbalance in vapor-solid reaction perovskite films, arising from a diffusion-limited top-down crystallization process. To address this issue, we propose a Stoichiometric Gradient Rebalancing (SGR) strategy, which involves the vapor deposition of PbI2 and PbCl2 in precise ratios followed by a re-reaction step. This simple yet effective approach homogenizes the vertical composition, reduces trap density, and enhances crystal quality. As a result, a power conversion efficiency (PCE) of 22.45% is achieved in small-area devices (0.148 cm2) and 19.92% in mini-modules (5 × 5 cm2). Moreover, the devices retain over 80% of their initial efficiency after 500 hours of continuous operation at the maximum power point. This work provides a viable strategy for improving the crystal quality of vapor-deposited perovskites and deepens the understanding of their crystallization, offering valuable insights for future advancements in vapor-deposited perovskites.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"1 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335087","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}
Rodrigo Andrés Espinosa-Flores, Martin Daniel Trejo-Valdez, María Elena Manríquez-Ramírez, Francisco Javier Tzompantzi-Morales, Hugo Martínez-Gutiérrez, Milla Vikberg, Tanja Kallio, Arturo Susarrey-Arce
Metal–organic frameworks (MOFs) are a versatile class of materials with significant potential for electrochemical CO2 reduction to multicarbon products. Most MOFs for electrocatalysis rely on benzene-ring-containing linkers, but their limited electrocatalytic activity hinders progress. Flexible MOFs, constructed from aliphatic-chain-containing linkers, offer an alternative due to their ability to respond to external stimuli such as electricity. Despite their potential, few studies have explored flexible MOFs for electrochemical CO2 reduction to value-added liquid products. This work synthesized two MOFs using metal nuclei (Mg and Zn) and distinct organic linkers: oxalic acid and 2,5-dihydroxyterephthalic acid (H4DOBDC, MOF-74). Electrochemical analysis revealed that the flexible MOF derived from oxalic acid exhibited superior charge transport properties, as confirmed by electrochemical impedance spectroscopy (EIS). Structural and chemical analyses, such as TEM, XRD, XPS, and acidity tests with pyridine, were performed using the synthesized MOFs. In situ ATR-FTIR during electrolysis and post-electrolysis using 1H NMR revealed the production of diverse carbon products, including ethanol, isopropanol, and methanol. The oxalic acid MOF demonstrated superior selectivity over well-known MOF-74 at −0.19 V vs. RHE. This study highlights the advantages of flexible MOFs over conventional benzene-based frameworks and paves the way for their application in CO2 electroreduction to liquid products.
{"title":"Electrochemical CO2 reduction to alcohols using flexible and rigid MOF electrocatalysts","authors":"Rodrigo Andrés Espinosa-Flores, Martin Daniel Trejo-Valdez, María Elena Manríquez-Ramírez, Francisco Javier Tzompantzi-Morales, Hugo Martínez-Gutiérrez, Milla Vikberg, Tanja Kallio, Arturo Susarrey-Arce","doi":"10.1039/d5ta00224a","DOIUrl":"https://doi.org/10.1039/d5ta00224a","url":null,"abstract":"Metal–organic frameworks (MOFs) are a versatile class of materials with significant potential for electrochemical CO<small><sub>2</sub></small> reduction to multicarbon products. Most MOFs for electrocatalysis rely on benzene-ring-containing linkers, but their limited electrocatalytic activity hinders progress. Flexible MOFs, constructed from aliphatic-chain-containing linkers, offer an alternative due to their ability to respond to external stimuli such as electricity. Despite their potential, few studies have explored flexible MOFs for electrochemical CO<small><sub>2</sub></small> reduction to value-added liquid products. This work synthesized two MOFs using metal nuclei (Mg and Zn) and distinct organic linkers: oxalic acid and 2,5-dihydroxyterephthalic acid (H<small><sub>4</sub></small>DOBDC, MOF-74). Electrochemical analysis revealed that the flexible MOF derived from oxalic acid exhibited superior charge transport properties, as confirmed by electrochemical impedance spectroscopy (EIS). Structural and chemical analyses, such as TEM, XRD, XPS, and acidity tests with pyridine, were performed using the synthesized MOFs. <em>In situ</em> ATR-FTIR during electrolysis and post-electrolysis using <small><sup>1</sup></small>H NMR revealed the production of diverse carbon products, including ethanol, isopropanol, and methanol. The oxalic acid MOF demonstrated superior selectivity over well-known MOF-74 at −0.19 V <em>vs.</em> RHE. This study highlights the advantages of flexible MOFs over conventional benzene-based frameworks and paves the way for their application in CO<small><sub>2</sub></small> electroreduction to liquid products.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"44 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329199","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}
Real-time, low-power, and selective detection of ammonia (NH3) is of critical importance in semiconductor manufacturing, environmental monitoring, and occupational safety. However, current sensing technologies often fall short in achieving a balance between sensitivity, stability, device integration, and user accessibility. In this work, we introduce a structurally asymmetric porous organic polymer membrane, synthesized via a liquid-liquid interfacial acylhydrazone condensation reaction, that enables rapid (∼1 s), reversible, and visually perceptible colorimetric sensing of NH3. The membrane exhibits dynamic keto-enol tautomerism and a well-defined anisotropic morphology—featuring a dense organic-phase side and a highly porous, fibrous aqueous-phase side—that collectively enhance molecular diffusion and optical responsiveness. Upon exposure to NH3, the disruption of intramolecular hydrogen bonding within the membrane backbone induces a pronounced absorption red-shift and a visible color transition from pale yellow to orange. Building on these molecular-level interactions, we engineer a laminated optical sensor that leverages UV-vis absorption changes for device-level signal transduction, achieving a detection limit as low as 1 ppm. Additionally, we implement a smartphone-assisted RGB extraction method to enable semi-quantitative and user-friendly data analysis, highlighting the potential of the membrane for intelligent, field-deployable sensing. This work establishes a new paradigm in Porous organic polymer-based gas sensors by uniting dynamic covalent chemistry, interfacial nanostructuring, and accessible device engineering to meet the demands of next-generation ammonia monitoring.
{"title":"A Colorimetric Ammonia Sensor Based on Interfacially Assembled Porous Polymer Membrane with Hydrogen-Bond-Responsive Optical Transduction","authors":"Zebiao Qiu, Qianchi Xiong, Heng Zhang, Yue Xiao, Ling Zhang, Ruijuan Wen, Liping Ding, Haonan Peng, Yu Fang","doi":"10.1039/d5ta03808a","DOIUrl":"https://doi.org/10.1039/d5ta03808a","url":null,"abstract":"Real-time, low-power, and selective detection of ammonia (NH3) is of critical importance in semiconductor manufacturing, environmental monitoring, and occupational safety. However, current sensing technologies often fall short in achieving a balance between sensitivity, stability, device integration, and user accessibility. In this work, we introduce a structurally asymmetric porous organic polymer membrane, synthesized via a liquid-liquid interfacial acylhydrazone condensation reaction, that enables rapid (∼1 s), reversible, and visually perceptible colorimetric sensing of NH3. The membrane exhibits dynamic keto-enol tautomerism and a well-defined anisotropic morphology—featuring a dense organic-phase side and a highly porous, fibrous aqueous-phase side—that collectively enhance molecular diffusion and optical responsiveness. Upon exposure to NH3, the disruption of intramolecular hydrogen bonding within the membrane backbone induces a pronounced absorption red-shift and a visible color transition from pale yellow to orange. Building on these molecular-level interactions, we engineer a laminated optical sensor that leverages UV-vis absorption changes for device-level signal transduction, achieving a detection limit as low as 1 ppm. Additionally, we implement a smartphone-assisted RGB extraction method to enable semi-quantitative and user-friendly data analysis, highlighting the potential of the membrane for intelligent, field-deployable sensing. This work establishes a new paradigm in Porous organic polymer-based gas sensors by uniting dynamic covalent chemistry, interfacial nanostructuring, and accessible device engineering to meet the demands of next-generation ammonia monitoring.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"13 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329301","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}
In this study, through defect engineering, a series of vanillin (Van)-modified Fe-MOF (FBVx, where x represents the molar ratio of Van to H2BDC) featuring a unique non-carboxylic ligand structure has been synthesized and then applied to the microwave (MW) catalyzed degradation of tetracycline (TC). Among them, FBV0.4 exhibits the best performance with which the degradation ratio of TC exceeds 98% in 10 min. Characterization and experimental results reveal its enrichment of unsaturated Fe sites (Fe(CUS)), surface oxygen vacancies (Ovs), and the presence of a multi-level pore structure. Under MW, (Fe(CUS) serves as active centers, facilitating the adsorption and activation of the reactants. Ovs can alter the electronic structure of the material, enhance its response to microwave, and improve its catalytic activity. The multi-level pore structure provides a large specific surface area and abundant diffusion channels, facilitating the contact between TC molecules and the active sites. Iron quantum dots and the multi-level pore structure could induce Near-field Enhancement or plasmon resonance energy transfer (PRET), promoting electron transfer. Quenching experiments indicates that the primary active species are ·OH, ·O2-, and h+. Notably, the required dosage of this catalyst is low, while its pH adaptation range is broad, it also exhibits strong anti-interference capabilities, and can maintain good activity even after 5 cycles. This paper proposes a research approach for preparing high-performance Fe-MOF MW catalysts with abundant defect vacancies and a multi-level pore structure.
{"title":"Microwave catalytic degradation of tetracycline by Van modified Fe-MOF: Regulation of defect engineering and its performance under microwave","authors":"Jingjing Wu, Zhiyu Yan, Jingying Shi, Lu Lu, Bing Sun, Ying Yu","doi":"10.1039/d5ta02433a","DOIUrl":"https://doi.org/10.1039/d5ta02433a","url":null,"abstract":"In this study, through defect engineering, a series of vanillin (Van)-modified Fe-MOF (FBVx, where x represents the molar ratio of Van to H2BDC) featuring a unique non-carboxylic ligand structure has been synthesized and then applied to the microwave (MW) catalyzed degradation of tetracycline (TC). Among them, FBV0.4 exhibits the best performance with which the degradation ratio of TC exceeds 98% in 10 min. Characterization and experimental results reveal its enrichment of unsaturated Fe sites (Fe(CUS)), surface oxygen vacancies (Ovs), and the presence of a multi-level pore structure. Under MW, (Fe(CUS) serves as active centers, facilitating the adsorption and activation of the reactants. Ovs can alter the electronic structure of the material, enhance its response to microwave, and improve its catalytic activity. The multi-level pore structure provides a large specific surface area and abundant diffusion channels, facilitating the contact between TC molecules and the active sites. Iron quantum dots and the multi-level pore structure could induce Near-field Enhancement or plasmon resonance energy transfer (PRET), promoting electron transfer. Quenching experiments indicates that the primary active species are ·OH, ·O2-, and h+. Notably, the required dosage of this catalyst is low, while its pH adaptation range is broad, it also exhibits strong anti-interference capabilities, and can maintain good activity even after 5 cycles. This paper proposes a research approach for preparing high-performance Fe-MOF MW catalysts with abundant defect vacancies and a multi-level pore structure.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"46 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329197","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}
Interfacial modification of carbon black (CB)-filled natural rubber (NR) composites is crucial for achieving uniform CB dispersion and robust interfacial interaction, with the goals of improving mechanical properties and reducing hysteresis loss. In this study, we reported a one-step synthesis of thioamide-functionalized polysulfide (SCA) via inverse vulcanization of sulfur with cyclohexylamine and the simultaneous conversion of amino to thioamide groups. SCA could serve as a novel interfacial modifier for NR/CB composites, in which thioamide groups form robust hydrogen bonds with oxygen-containing groups on CB surface, and the polysulfide fragments cleave and covalently couple with NR, enabling the establishment of SCA-mediated bridges between NR and CB. Consequently, the incorporation of SCA remarkably suppresses CB aggregation and enhances interfacial interaction, resulting in substantial decrease in the hysteresis loss of the composites. More importantly, the effects of SCA molecular structure on the composite structure and properties are systematically investigated. The thioamide content is found to be critical for improving CB dispersion within the composites, while the reactivity between NR and polysulfide fragments in SCA is the dominant factor governing interfacial interaction.
{"title":"Mediating Carbon Black-Natural Rubber Interface by Thioamide-Functionalized Polysulfide for Energy-Saving Composites","authors":"Ruoyan Huang, Dong Wang, Zhenghai Tang, Baochun Guo, Liqun Zhang","doi":"10.1039/d5ta04129e","DOIUrl":"https://doi.org/10.1039/d5ta04129e","url":null,"abstract":"Interfacial modification of carbon black (CB)-filled natural rubber (NR) composites is crucial for achieving uniform CB dispersion and robust interfacial interaction, with the goals of improving mechanical properties and reducing hysteresis loss. In this study, we reported a one-step synthesis of thioamide-functionalized polysulfide (SCA) via inverse vulcanization of sulfur with cyclohexylamine and the simultaneous conversion of amino to thioamide groups. SCA could serve as a novel interfacial modifier for NR/CB composites, in which thioamide groups form robust hydrogen bonds with oxygen-containing groups on CB surface, and the polysulfide fragments cleave and covalently couple with NR, enabling the establishment of SCA-mediated bridges between NR and CB. Consequently, the incorporation of SCA remarkably suppresses CB aggregation and enhances interfacial interaction, resulting in substantial decrease in the hysteresis loss of the composites. More importantly, the effects of SCA molecular structure on the composite structure and properties are systematically investigated. The thioamide content is found to be critical for improving CB dispersion within the composites, while the reactivity between NR and polysulfide fragments in SCA is the dominant factor governing interfacial interaction.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"238 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329299","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}
Xu Zhang, Lin Tao, Davoud Dastan, Hongwei Zhang, Baochang Gao
The performance of single-atom catalysts in electrocatalytic processes can be effectively enhanced through the doping of tailored asymmetric coordination environments. However, understanding the electrochemical stability of doped single-atom structures (SAS) under operating conditions remains challenging. In this study, density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations are employed to elucidate the combined effects of proton-electron adsorption and Cu leaching from the Cu-N4 structure. By considering 6 thermodynamically and kinetically stable heteroatom-doped CuN3X structures, the relationship between the proton-electron adsorption energy barriers and Cu leaching energy barriers for 96 proton adsorption configurations is explored. A trade-off between these two factors leads to the identification of the CuN3B structure as the most stable. Surface phase diagrams indicate that B doping effectively suppresses Cu leaching, while S doping exacerbates it. Electronic structure analysis further highlights that B doping enhances the hybridization coincidence of Cu-N orbitals, thereby strengthening the Cu-N bond, reducing proton adsorption on N, and ultimately stabilizing the Cu single-atom structure. Overall, this study investigates the electrochemical stability of Cu SAS and their underlying mechanisms, offering new insights into the electrochemical stability of SAS.
{"title":"Tuning the Electrochemical Stability of Carbon Based Single-Atom Structures via Doping: Trade-off Electrosorption/Leaching Behavior","authors":"Xu Zhang, Lin Tao, Davoud Dastan, Hongwei Zhang, Baochang Gao","doi":"10.1039/d5ta03307a","DOIUrl":"https://doi.org/10.1039/d5ta03307a","url":null,"abstract":"The performance of single-atom catalysts in electrocatalytic processes can be effectively enhanced through the doping of tailored asymmetric coordination environments. However, understanding the electrochemical stability of doped single-atom structures (SAS) under operating conditions remains challenging. In this study, density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations are employed to elucidate the combined effects of proton-electron adsorption and Cu leaching from the Cu-N4 structure. By considering 6 thermodynamically and kinetically stable heteroatom-doped CuN3X structures, the relationship between the proton-electron adsorption energy barriers and Cu leaching energy barriers for 96 proton adsorption configurations is explored. A trade-off between these two factors leads to the identification of the CuN3B structure as the most stable. Surface phase diagrams indicate that B doping effectively suppresses Cu leaching, while S doping exacerbates it. Electronic structure analysis further highlights that B doping enhances the hybridization coincidence of Cu-N orbitals, thereby strengthening the Cu-N bond, reducing proton adsorption on N, and ultimately stabilizing the Cu single-atom structure. Overall, this study investigates the electrochemical stability of Cu SAS and their underlying mechanisms, offering new insights into the electrochemical stability of SAS.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"25 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329348","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}
Yinghui Li, Yingyan Zhao, Shusheng Cao, Zi Li, Yueqing Shen, Yasemen Kuddusi, Chong Lu, Xi Lin, Andreas Züttel, Chongnan Ye, Jianxin Zou
High-entropy alloys (HEAs) featuring with multi-element active sites show exclusive catalytic ability, as well as great potential to store hydrogen (H2) at room temperature by adjusting the electronic and geometrical factors. Herein, a TiCrMnFeZr HEA was adopted to improve the hydrogen storage properties of magnesium hydride (MgH2). It was demonstrated that MgH2 provides substantial cushion protection for the crystal structure and hydrogen storage capacity of TiCrMnFeZr HEA during the ball milling, while the TiCrMnFeZr HEA exhibits superior catalytic ability to the dissociation of H-H and Mg-H bonds. Particularly, the MgH2-40 wt.% TiCrMnFeZr composite can absorb and desorb 0.72 wt.% H2 even at room temperature. Moreover, MgH2 starts to release hydrogen at 162 oC, and 90 % of stored H2 (~3.7 wt.%) can be released at 230 oC within 60 min. There is no capacity fading after 20 cycles at 300 oC for both TiCrMnFeZr HEA and Mg/MgH2 phases in the composite, showing an outstanding cyclic performance. Microstructure investigations reveal that the well-protected TiCrMnFeZr HEA particles surfaces perform as the catalytic sites for the dissociation of Mg-H bonds because of its intrinsic multivalent electronic configuration, and also serve as the channels for hydrogen sorption in Mg/MgH2. Such a method to design and synthesize high-performance Mg-based hydrogen storage composites and to provide H2 in two steps paves a new way to realize their practical applications in the hydrogen energy field.
{"title":"Study on mechanisms of two-step hydrogen sorption in MgH2-TiCrMnFeZr high-entropy alloy composite","authors":"Yinghui Li, Yingyan Zhao, Shusheng Cao, Zi Li, Yueqing Shen, Yasemen Kuddusi, Chong Lu, Xi Lin, Andreas Züttel, Chongnan Ye, Jianxin Zou","doi":"10.1039/d5ta03497c","DOIUrl":"https://doi.org/10.1039/d5ta03497c","url":null,"abstract":"High-entropy alloys (HEAs) featuring with multi-element active sites show exclusive catalytic ability, as well as great potential to store hydrogen (H<small><sub>2</sub></small>) at room temperature by adjusting the electronic and geometrical factors. Herein, a TiCrMnFeZr HEA was adopted to improve the hydrogen storage properties of magnesium hydride (MgH<small><sub>2</sub></small>). It was demonstrated that MgH<small><sub>2</sub></small> provides substantial cushion protection for the crystal structure and hydrogen storage capacity of TiCrMnFeZr HEA during the ball milling, while the TiCrMnFeZr HEA exhibits superior catalytic ability to the dissociation of H-H and Mg-H bonds. Particularly, the MgH<small><sub>2</sub></small>-40 wt.% TiCrMnFeZr composite can absorb and desorb 0.72 wt.% H<small><sub>2</sub></small> even at room temperature. Moreover, MgH<small><sub>2</sub></small> starts to release hydrogen at 162 <small><sup>o</sup></small>C, and 90 % of stored H<small><sub>2</sub></small> (~3.7 wt.%) can be released at 230 <small><sup>o</sup></small>C within 60 min. There is no capacity fading after 20 cycles at 300 <small><sup>o</sup></small>C for both TiCrMnFeZr HEA and Mg/MgH<small><sub>2</sub></small> phases in the composite, showing an outstanding cyclic performance. Microstructure investigations reveal that the well-protected TiCrMnFeZr HEA particles surfaces perform as the catalytic sites for the dissociation of Mg-H bonds because of its intrinsic multivalent electronic configuration, and also serve as the channels for hydrogen sorption in Mg/MgH<small><sub>2</sub></small>. Such a method to design and synthesize high-performance Mg-based hydrogen storage composites and to provide H<small><sub>2</sub></small> in two steps paves a new way to realize their practical applications in the hydrogen energy field.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"30 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329349","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}
Ilia Tertov, François Fauth, Emmanuelle Suard, Thomas Hansen, François Weill, Pierre-Etienne Cabelguen, Christian Masquelier, Laurence Croguennec
A combination of synchrotron X-ray powder diffraction (SXRPD) and neutron powder diffraction (NPD) is used to investigate phase equilibrium during the synthesis of LiNi0.46Mn1.54O4 (LNMO) powders from a reagent mixture. A Li-deficient disordered LNMO begins to form at T ≈ 460 °C and as the temperature increases, oxygen release triggers the formation of impurity phases. Advanced structural characterization of quenched LNMO samples, along with in situ SXRPD experiments, reveals that a layered oxide impurity crystallizes between 700 °C and 900 °C. At temperatures of 900 °C and above, this impurity phase transforms into a rock-salt type one, while a Li-rich layered oxide impurity also emerges. This leads to the coexistence of three phases at T ≥ 900 °C: LNMO spinel, rock salt, and Li-rich layered oxide. These transformations affect significantly the composition of the targeted LNMO spinel phase, which highlights the challenges in achieving phase purity with the desired stoichiometry in this complex system. The findings provide valuable insights for optimizing the LNMO synthesis so as to prepare high-performance positive electrode materials.
{"title":"Phase equilibrium during the synthesis of LiNi0.46Mn1.54O4: comprehensive X-ray & neutron powder diffraction study","authors":"Ilia Tertov, François Fauth, Emmanuelle Suard, Thomas Hansen, François Weill, Pierre-Etienne Cabelguen, Christian Masquelier, Laurence Croguennec","doi":"10.1039/d5ta01514f","DOIUrl":"https://doi.org/10.1039/d5ta01514f","url":null,"abstract":"A combination of synchrotron X-ray powder diffraction (SXRPD) and neutron powder diffraction (NPD) is used to investigate phase equilibrium during the synthesis of LiNi<small><sub>0.46</sub></small>Mn<small><sub>1.54</sub></small>O<small><sub>4</sub></small> (LNMO) powders from a reagent mixture. A Li-deficient disordered LNMO begins to form at <em>T</em> ≈ 460 °C and as the temperature increases, oxygen release triggers the formation of impurity phases. Advanced structural characterization of quenched LNMO samples, along with <em>in situ</em> SXRPD experiments, reveals that a layered oxide impurity crystallizes between 700 °C and 900 °C. At temperatures of 900 °C and above, this impurity phase transforms into a rock-salt type one, while a Li-rich layered oxide impurity also emerges. This leads to the coexistence of three phases at <em>T</em> ≥ 900 °C: LNMO spinel, rock salt, and Li-rich layered oxide. These transformations affect significantly the composition of the targeted LNMO spinel phase, which highlights the challenges in achieving phase purity with the desired stoichiometry in this complex system. The findings provide valuable insights for optimizing the LNMO synthesis so as to prepare high-performance positive electrode materials.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"25 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329198","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}
All-solid-state Na-ion batteries have attracted considerable attention because of their advantages such as high safety, high energy density, and low cost. Solid electrolytes used in these batteries require high Na-ion conductivity to minimize energy loss, high electronic resistivity to prevent self-discharge, and high oxidation resistance to enable the use of high-potential cathodes. Recently, NaTaCl6 was reported to possess both high oxidation resistance and ionic conductivity, and its ionic conductivity improved with a decrease in its crystallinity. Therefore, in this study, we aimed to further reduce the crystallinity of NaTaCl6 and improve its ionic conductivity and electronic resistivity through multicomponentization. The verified composition was Na2Ta0.625Zr0.25Ga0.125Cl5.625(CO3)0.25(BO3)0.125, wherein polyatomic anions (CO32− and BO33−) were expected to have inductive effects that maintained the high oxidation resistance of chloride. Through multicomponentization, the NaTaCl6 phase transitioned to a low-crystallinity state, resulting in a significant improvement in the ionic conductivity (1.2 × 10−3 S cm−1), which was approximately ten times higher than that of crystalline NaTaCl6 (1.1 × 10−4 S cm−1). The electronic resistivity of the low-crystallinity multicomponent was more than one order of magnitude higher than that of crystalline NaTaCl6, effectively suppressing self-discharge and improving the energy-storage preservation properties of the material. Furthermore, the multicomponent NaTaCl6 retained a high oxidation resistance with an oxidation limit of 4.6 V vs. Na/Na+. Thus, this multicomponentization strategy simultaneously retains high oxidation resistance while improving the ionic conductivity and electronic resistivity of the electrolyte material, thereby enabling the development of high-performance all-solid-state Na-ion batteries.
全固态钠离子电池以其高安全性、高能量密度、低成本等优点受到了广泛的关注。这些电池中使用的固体电解质需要高钠离子导电性以最大限度地减少能量损失，高电子电阻率以防止自放电，以及高抗氧化性以使用高电位阴极。近年来，NaTaCl6同时具有较高的抗氧化性和离子电导率，其离子电导率随着结晶度的降低而提高。因此，在本研究中，我们旨在通过多组化进一步降低NaTaCl6的结晶度，提高其离子电导率和电子电阻率。经验证的组成为Na2Ta0.625Zr0.25Ga0.125Cl5.625(CO3)0.25(BO3)0.125，其中多原子阴离子（CO32−和BO33−）具有诱导作用，保持了氯离子的高抗氧化性。通过多组化，natac16相变为低结晶度状态，离子电导率显著提高（1.2 × 10−3 S cm−1），约为晶体natac16 （1.1 × 10−4 S cm−1）的10倍。低结晶度多组分的电子电阻率比结晶NaTaCl6高出一个数量级以上，有效抑制了材料的自放电，提高了材料的储能保存性能。此外，与Na/Na+相比，多组分NaTaCl6保持了较高的抗氧化性，氧化极限为4.6 V。因此，这种多组化策略在保持高抗氧化性的同时，提高了电解质材料的离子电导率和电子电阻率，从而使高性能全固态钠离子电池的发展成为可能。
{"title":"Multicomponentization of a super-Na ionic conductor chloride NaTaCl6, enhancing ionic conductivity and electronic resistivity","authors":"Keisuke Makino, Naoto Tanibata, Takaaki Natori, Tomoko Nakano, Hayami Takeda, Masanobu Nakayama","doi":"10.1039/d4ta08447k","DOIUrl":"https://doi.org/10.1039/d4ta08447k","url":null,"abstract":"All-solid-state Na-ion batteries have attracted considerable attention because of their advantages such as high safety, high energy density, and low cost. Solid electrolytes used in these batteries require high Na-ion conductivity to minimize energy loss, high electronic resistivity to prevent self-discharge, and high oxidation resistance to enable the use of high-potential cathodes. Recently, NaTaCl<small><sub>6</sub></small> was reported to possess both high oxidation resistance and ionic conductivity, and its ionic conductivity improved with a decrease in its crystallinity. Therefore, in this study, we aimed to further reduce the crystallinity of NaTaCl<small><sub>6</sub></small> and improve its ionic conductivity and electronic resistivity through multicomponentization. The verified composition was Na<small><sub>2</sub></small>Ta<small><sub>0.625</sub></small>Zr<small><sub>0.25</sub></small>Ga<small><sub>0.125</sub></small>Cl<small><sub>5.625</sub></small>(CO<small><sub>3</sub></small>)<small><sub>0.25</sub></small>(BO<small><sub>3</sub></small>)<small><sub>0.125</sub></small>, wherein polyatomic anions (CO<small><sub>3</sub></small><small><sup>2−</sup></small> and BO<small><sub>3</sub></small><small><sup>3−</sup></small>) were expected to have inductive effects that maintained the high oxidation resistance of chloride. Through multicomponentization, the NaTaCl<small><sub>6</sub></small> phase transitioned to a low-crystallinity state, resulting in a significant improvement in the ionic conductivity (1.2 × 10<small><sup>−3</sup></small> S cm<small><sup>−1</sup></small>), which was approximately ten times higher than that of crystalline NaTaCl<small><sub>6</sub></small> (1.1 × 10<small><sup>−4</sup></small> S cm<small><sup>−1</sup></small>). The electronic resistivity of the low-crystallinity multicomponent was more than one order of magnitude higher than that of crystalline NaTaCl<small><sub>6</sub></small>, effectively suppressing self-discharge and improving the energy-storage preservation properties of the material. Furthermore, the multicomponent NaTaCl<small><sub>6</sub></small> retained a high oxidation resistance with an oxidation limit of 4.6 V <em>vs.</em> Na/Na<small><sup>+</sup></small>. Thus, this multicomponentization strategy simultaneously retains high oxidation resistance while improving the ionic conductivity and electronic resistivity of the electrolyte material, thereby enabling the development of high-performance all-solid-state Na-ion batteries.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":"15 1","pages":""},"PeriodicalIF":11.9,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329200","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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