Linjing Su, Jingyan Xu, Rong Huang, Jinlan Liao, Lingyan Zhao, Ling Li, Zhi Zhang, Yuhao Xiong
Phosphatase‐mimicking nanozymes provide highly stable enzyme‐like activity but remain limited by their static catalytic nature. Herein, this study achieves flexoelectricity‐driven dynamic modulation of nanozyme activity by employing gadolinium‐based nanoflowers (GNF) with hierarchical ultrathin architectures. These structures possess curvature‐induced strain gradients and hydroxyl‐rich surfaces, which generate pronounced flexoelectric polarization under mild ultrasonic excitation. Finite element simulations reveal that mechanical loading induces localized strain gradients and surface potential anisotropy, forming a structural basis for dynamic interfacial charge redistribution. Density functional theory calculations demonstrate that flexoelectric polarization lowers the activation barrier and shifted the rate‐determining step, transforming the reaction pathway. This polarization enhances the Lewis acidity of Gd 3+ sites and stabilized transition states, thereby accelerating phosphate ester hydrolysis. The GNF nanozyme exhibits excellent phosphatase‐like catalytic activity and enables the ultrasensitive colorimetric detection of biologically relevant targets, such as bovine serum albumin and fluoride ions, with low detection limits and robust matrix tolerance. This study pioneers the integration of strain‐gradient‐induced polarization into nanozyme catalysis, establishing a generalizable framework for constructing adaptive and mechanically responsive artificial enzymes.
{"title":"Flexoelectric Polarization‐Enhanced Gd‐Based Nanoflowers for Efficient Phosphatase‐Mimicking Dephosphorylation","authors":"Linjing Su, Jingyan Xu, Rong Huang, Jinlan Liao, Lingyan Zhao, Ling Li, Zhi Zhang, Yuhao Xiong","doi":"10.1002/sstr.202500559","DOIUrl":"https://doi.org/10.1002/sstr.202500559","url":null,"abstract":"Phosphatase‐mimicking nanozymes provide highly stable enzyme‐like activity but remain limited by their static catalytic nature. Herein, this study achieves flexoelectricity‐driven dynamic modulation of nanozyme activity by employing gadolinium‐based nanoflowers (GNF) with hierarchical ultrathin architectures. These structures possess curvature‐induced strain gradients and hydroxyl‐rich surfaces, which generate pronounced flexoelectric polarization under mild ultrasonic excitation. Finite element simulations reveal that mechanical loading induces localized strain gradients and surface potential anisotropy, forming a structural basis for dynamic interfacial charge redistribution. Density functional theory calculations demonstrate that flexoelectric polarization lowers the activation barrier and shifted the rate‐determining step, transforming the reaction pathway. This polarization enhances the Lewis acidity of Gd 3+ sites and stabilized transition states, thereby accelerating phosphate ester hydrolysis. The GNF nanozyme exhibits excellent phosphatase‐like catalytic activity and enables the ultrasensitive colorimetric detection of biologically relevant targets, such as bovine serum albumin and fluoride ions, with low detection limits and robust matrix tolerance. This study pioneers the integration of strain‐gradient‐induced polarization into nanozyme catalysis, establishing a generalizable framework for constructing adaptive and mechanically responsive artificial enzymes.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/sstr.202500559","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147334072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polymeric foams have garnered significant interest in advanced engineering applications due to their unique porous architectures. Ice templating represents a promising strategy for creating polymeric foams with tunable pore morphology, yet faces practical constraints including reliance on energy‐intensive lyophilization and/or insufficient mechanical properties of the resulting foams. To address this challenge, a strategy is developed to prepare mechanically robust polymeric foams by photo‐crosslinking ice‐templated emulsions. By incorporating dynamic hindered urea bonds into the emulsion, dynamic network reconfiguration is achieved, which dramatically improves mechanical properties. The resultant foam (≈65% porosity) exhibits tensile strength and breaking strains of 7.9 MPa and 533%, with toughness of 15.8 MJ m −3 . In addition, this strategy permits the construction of intricate 3D architectures using 3D‐printed sacrificial thermoplastic templates, expanding their potential applications in demanding engineering scenarios.
{"title":"Dynamic Network Reconfiguration Toward Mechanically Robust Polymeric Foam via Ice Templating","authors":"Chenggang Xu, Xing‐Qun Pu, Runzhi Lu, Yongbo Jiang, Qian Zhao, Zizheng Fang, Tao Xie","doi":"10.1002/sstr.202500570","DOIUrl":"https://doi.org/10.1002/sstr.202500570","url":null,"abstract":"Polymeric foams have garnered significant interest in advanced engineering applications due to their unique porous architectures. Ice templating represents a promising strategy for creating polymeric foams with tunable pore morphology, yet faces practical constraints including reliance on energy‐intensive lyophilization and/or insufficient mechanical properties of the resulting foams. To address this challenge, a strategy is developed to prepare mechanically robust polymeric foams by photo‐crosslinking ice‐templated emulsions. By incorporating dynamic hindered urea bonds into the emulsion, dynamic network reconfiguration is achieved, which dramatically improves mechanical properties. The resultant foam (≈65% porosity) exhibits tensile strength and breaking strains of 7.9 MPa and 533%, with toughness of 15.8 MJ m −3 . In addition, this strategy permits the construction of intricate 3D architectures using 3D‐printed sacrificial thermoplastic templates, expanding their potential applications in demanding engineering scenarios.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"6 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/sstr.202500570","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Converting CO 2 into high‐value‐added products via “artificial photosynthesis” under mild conditions is a promising yet challenging strategy for developing efficient photocatalysts. This study reports a simple two‐step solvothermal approach to fabricate the dual‐metal–organic framework (MOF) nanocomposite NH 2 ‐UiO‐66@PCN‐224 (NU‐66@PCN‐224) with tightly integrated interfaces, which achieves efficient CO 2 to CO photocatalytic reduction under light irradiation. The epitaxially grown PCN‐224, composed of Zr 6 clusters and tetrakis (4‐carboxyphenyl) porphyrin (TCPP), serves as a shell layer and a visible light‐absorbing antenna, thereby broadening the light absorption range of the composite material. Moreover, the tightly integrated interfaces of NU‐66@PCN‐224 enhance the mobility of photogenerated charge carriers, consequently enhancing its capability for CO 2 catalytic reduction. As a result, the combination of NU‐66 and PCN‐224 retains their individual advantages while achieving a synergistic enhancement of both adsorption and catalysis, further improving the photocatalytic performance. The as‐prepared NU‐66@PCN‐224 catalyst exhibits outstanding photocatalytic performance, yielding 74.6 μmol g −1 h −1 of CO under irradiation without sacrificial agents or photosensitizers. This work demonstrates a straightforward and effective method for designing MOF‐on‐MOF photocatalysts with enhanced photoactivity.
{"title":"Construction of NH<sub>2</sub>‐UiO‐66@PCN‐224 Nanocomposites with Tightly Integrated Interfaces for Boosting Photocatalytic CO<sub>2</sub> Reduction with H<sub>2</sub>O","authors":"Jinglian Fan, Yiming He, Wenji Li, Zhongxing Zhao, Zhenxia Zhao","doi":"10.1002/sstr.202500206","DOIUrl":"https://doi.org/10.1002/sstr.202500206","url":null,"abstract":"Converting CO 2 into high‐value‐added products via “artificial photosynthesis” under mild conditions is a promising yet challenging strategy for developing efficient photocatalysts. This study reports a simple two‐step solvothermal approach to fabricate the dual‐metal–organic framework (MOF) nanocomposite NH 2 ‐UiO‐66@PCN‐224 (NU‐66@PCN‐224) with tightly integrated interfaces, which achieves efficient CO 2 to CO photocatalytic reduction under light irradiation. The epitaxially grown PCN‐224, composed of Zr 6 clusters and tetrakis (4‐carboxyphenyl) porphyrin (TCPP), serves as a shell layer and a visible light‐absorbing antenna, thereby broadening the light absorption range of the composite material. Moreover, the tightly integrated interfaces of NU‐66@PCN‐224 enhance the mobility of photogenerated charge carriers, consequently enhancing its capability for CO 2 catalytic reduction. As a result, the combination of NU‐66 and PCN‐224 retains their individual advantages while achieving a synergistic enhancement of both adsorption and catalysis, further improving the photocatalytic performance. The as‐prepared NU‐66@PCN‐224 catalyst exhibits outstanding photocatalytic performance, yielding 74.6 μmol g −1 h −1 of CO under irradiation without sacrificial agents or photosensitizers. This work demonstrates a straightforward and effective method for designing MOF‐on‐MOF photocatalysts with enhanced photoactivity.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"6 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147333661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Oil spills and water pollution present significant environmental challenges, calling for the development of sustainable and efficient material solutions. In this study, aerogels are prepared from chitosan and sodium alginate, two renewable natural polysaccharides, through ultrasonication‐assisted nanofiber assembly combined with freeze casting. This approach leverages the inherent electrostatic interactions between two polysaccharides to assemble nanofibers, which are then aggregated into an anisotropic honeycomb‐like cellular microstructure during freeze casting. The addition of methyltrimethoxysilane further consolidates the nanofiber network, resulting in CSNF‐Si aerogels with a superlow density of 0.0198 g cm −3 , yet high mechanical strength (105.7 kPa at 80% strain) and shape recovery (95% after 80% deformation). In addition, the aerogels exhibit superhydrophobicity with a water contact angle of 151° and a rolling angle of 4.3°, enabling effective oil absorption with capacities reaching up to 90 times their own weight. They also demonstrate excellent reusability over multiple oil absorption‐release cycles, thanks to their enhanced shape recovery ability. Furthermore, this study presents a hierarchical fabrication strategy that synergistically integrates molecular, nano‐, and microscale designs to reinforce and functionalize aerogels for sustainable engineering solutions.
石油泄漏和水污染提出了重大的环境挑战，要求开发可持续和高效的材料解决方案。以壳聚糖和海藻酸钠这两种可再生天然多糖为原料，采用超声辅助纳米纤维组装结合冷冻铸造法制备了气凝胶。这种方法利用两种多糖之间固有的静电相互作用来组装纳米纤维，然后在冷冻铸造过程中聚集成各向异性的蜂窝状细胞微观结构。甲基三甲氧基硅烷的加入进一步巩固了纳米纤维网络，使得CSNF - Si气凝胶具有0.0198 g cm−3的超低密度，但具有很高的机械强度（80%应变时105.7 kPa）和形状恢复（80%变形后95%）。此外，气凝胶具有超疏水性，水接触角为151°，滚动角为4.3°，有效吸油能力可达自身重量的90倍。由于其增强的形状恢复能力，它们在多次吸油释放周期中也表现出了出色的可重复使用性。此外，本研究提出了一种分层制造策略，该策略协同集成了分子、纳米和微尺度设计，以增强和功能化气凝胶，以实现可持续的工程解决方案。
{"title":"Biomass Nanofiber‐Assembled Superhydrophobic Aerogels with Simultaneously Enhanced Mechanical Strength and Shape Recovery","authors":"Xinyu Dong, Quyang Liu, Hao Zhuo, Yuan Cao, Yijing Zhao, Hongzhi Zheng, Linxin Zhong, Wei Zhai","doi":"10.1002/sstr.202500009","DOIUrl":"https://doi.org/10.1002/sstr.202500009","url":null,"abstract":"Oil spills and water pollution present significant environmental challenges, calling for the development of sustainable and efficient material solutions. In this study, aerogels are prepared from chitosan and sodium alginate, two renewable natural polysaccharides, through ultrasonication‐assisted nanofiber assembly combined with freeze casting. This approach leverages the inherent electrostatic interactions between two polysaccharides to assemble nanofibers, which are then aggregated into an anisotropic honeycomb‐like cellular microstructure during freeze casting. The addition of methyltrimethoxysilane further consolidates the nanofiber network, resulting in CSNF‐Si aerogels with a superlow density of 0.0198 g cm −3 , yet high mechanical strength (105.7 kPa at 80% strain) and shape recovery (95% after 80% deformation). In addition, the aerogels exhibit superhydrophobicity with a water contact angle of 151° and a rolling angle of 4.3°, enabling effective oil absorption with capacities reaching up to 90 times their own weight. They also demonstrate excellent reusability over multiple oil absorption‐release cycles, thanks to their enhanced shape recovery ability. Furthermore, this study presents a hierarchical fabrication strategy that synergistically integrates molecular, nano‐, and microscale designs to reinforce and functionalize aerogels for sustainable engineering solutions.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"6 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/sstr.202500009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhichao Yu, Juqing Li, Qiurui Zhang, Pei Xiang, Jincheng Lei
Humidity sensors functioned by 1D nanostructural metal oxides (1D NMOs) are promising for real‐time respiratory monitoring. However, the preparation and assembly of 1D NMOs on sensor structures are quite challenging due to the complicated synthesis procedures and vulnerability of nanomaterials. Herein, a multi‐laser processing technology is developed to fabricate nano‐cotton TiO 2 humidity sensors for respiratory monitoring. The nano‐cotton TiO 2 is in situ synthesized and assembled to the interdigitate electrodes of the sensor structure using the transmitted picosecond laser deposition. The as‐deposited TiO 2 layers are in situ post‐annealed by a CO 2 laser to optimize the crystallinity and phase compositions for humidity sensing. By investigating the evolution mechanism of the nanostructures of the laser‐induced plasma plumes during sputtering, it is demonstrated that the nanostructures of the laser‐deposited TiO 2 layers can be flexibly controlled by varying the target‐to‐substrate distance. The crystallinity, phase composition, surface roughness, and layer thickness of the nano‐cotton TiO 2 are estimated to evaluate the developed technology. The fabricated sensors exhibit high sensitivity and rapid response to the variation of relative humidity under both steady and transient states. To demonstrate for real‐time respiratory monitoring, the fabricated sensor is integrated into a commercial mask to monitor human's breathing under different respiratory modes.
{"title":"Laser‐Induced in situ Synthesis and Assembly of Nano‐Cotton TiO<sub>2</sub> Humidity Sensors with High Sensitivity and Fast Response for Real‐Time Respiratory Monitoring","authors":"Zhichao Yu, Juqing Li, Qiurui Zhang, Pei Xiang, Jincheng Lei","doi":"10.1002/sstr.202400593","DOIUrl":"https://doi.org/10.1002/sstr.202400593","url":null,"abstract":"Humidity sensors functioned by 1D nanostructural metal oxides (1D NMOs) are promising for real‐time respiratory monitoring. However, the preparation and assembly of 1D NMOs on sensor structures are quite challenging due to the complicated synthesis procedures and vulnerability of nanomaterials. Herein, a multi‐laser processing technology is developed to fabricate nano‐cotton TiO 2 humidity sensors for respiratory monitoring. The nano‐cotton TiO 2 is in situ synthesized and assembled to the interdigitate electrodes of the sensor structure using the transmitted picosecond laser deposition. The as‐deposited TiO 2 layers are in situ post‐annealed by a CO 2 laser to optimize the crystallinity and phase compositions for humidity sensing. By investigating the evolution mechanism of the nanostructures of the laser‐induced plasma plumes during sputtering, it is demonstrated that the nanostructures of the laser‐deposited TiO 2 layers can be flexibly controlled by varying the target‐to‐substrate distance. The crystallinity, phase composition, surface roughness, and layer thickness of the nano‐cotton TiO 2 are estimated to evaluate the developed technology. The fabricated sensors exhibit high sensitivity and rapid response to the variation of relative humidity under both steady and transient states. To demonstrate for real‐time respiratory monitoring, the fabricated sensor is integrated into a commercial mask to monitor human's breathing under different respiratory modes.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"6 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/sstr.202400593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147334137","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Han Zhao, Fangyu Zhu, Yusi Guo, Xuliang Deng, Wenwen Liu
Conventional methods to stimulate the metabolism of bone marrow mesenchymal stem cells (BMSCs) for osteogenic differentiation typically involve systemic mobilization, which faces challenges including limited in vivo half‐life, lack of selectivity, and potential side‐effects. Therefore, localized modulation of BMSCs represents a more efficient and safer alternative. However, few studies have explored the regulation of a localized stimuli‐responsive microenvironment to activate osteogenic differentiation via mitochondrial pathways and clarified its underlying mechanisms. Herein, a novel strategy to accelerate the metabolic switch of BMSCs in tissue defects through targeted modulation using built‐in magnetoelectric biomaterials is proposed. BMSCs cultured in the magnetoelectric microenvironment exhibited an increased mitochondrial membrane potential, the highest oxygen consumption rate and enhanced adenosine triphosphate production. Furthermore, BMSCs in the magnetoelectric microenvironment demonstrated a successful metabolic switch of energy resource from glycolysis to oxidative phosphorylation, indicating a strong tendency toward osteogenic differentiation. The highest multiclass metabolite profile, indicating the most active metabolic state, was shown in rats cranial defect model treated with magnetoelectric microenvironment. This research introduces a novel approach to accelerate bone defect repair by targeted modulation of BMSC mitochondria with magnetoelectric microenvironment and provides a promising direction for exploring the intrinsic mechanisms through which the magnetoelectric microenvironment promotes bone regeneration.
{"title":"Metabolic Mechanism of Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cell Regulated by Magnetoelectric Microenvironment","authors":"Han Zhao, Fangyu Zhu, Yusi Guo, Xuliang Deng, Wenwen Liu","doi":"10.1002/sstr.202400466","DOIUrl":"https://doi.org/10.1002/sstr.202400466","url":null,"abstract":"Conventional methods to stimulate the metabolism of bone marrow mesenchymal stem cells (BMSCs) for osteogenic differentiation typically involve systemic mobilization, which faces challenges including limited in vivo half‐life, lack of selectivity, and potential side‐effects. Therefore, localized modulation of BMSCs represents a more efficient and safer alternative. However, few studies have explored the regulation of a localized stimuli‐responsive microenvironment to activate osteogenic differentiation via mitochondrial pathways and clarified its underlying mechanisms. Herein, a novel strategy to accelerate the metabolic switch of BMSCs in tissue defects through targeted modulation using built‐in magnetoelectric biomaterials is proposed. BMSCs cultured in the magnetoelectric microenvironment exhibited an increased mitochondrial membrane potential, the highest oxygen consumption rate and enhanced adenosine triphosphate production. Furthermore, BMSCs in the magnetoelectric microenvironment demonstrated a successful metabolic switch of energy resource from glycolysis to oxidative phosphorylation, indicating a strong tendency toward osteogenic differentiation. The highest multiclass metabolite profile, indicating the most active metabolic state, was shown in rats cranial defect model treated with magnetoelectric microenvironment. This research introduces a novel approach to accelerate bone defect repair by targeted modulation of BMSC mitochondria with magnetoelectric microenvironment and provides a promising direction for exploring the intrinsic mechanisms through which the magnetoelectric microenvironment promotes bone regeneration.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"6 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/pdfdirect/10.1002/sstr.202400466","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147332879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cong Xi, Yixin Nie, Hongjuan Wang, Cunku Dong, Jiuhui Han, Xi-Wen Du
Catalytic hydrogenation of carbon dioxide to methanol offers a promising avenue for recycling CO2, enhancing environmental sustainability. Cu/ZnO has long been identified as one of the most effective heterogeneous catalysts for this reaction, yet the detailed understanding of its reaction mechanism and active sites remains incomplete. Recent advances have highlighted the critical role of defects, such as ZnCu steps and stacking faults on Cu surfaces, in enhancing catalyst performance. Here this concept is explored through first-principles surface simulations of six models, featuring diverse Cu–Zn combinations and specific coordination environments under realistic conditions. It is revealed that Cu/ZnO catalysts with kink defects, rather than surface ZnCu alloys, exhibit optimal activity for methanol synthesis. Specifically, the findings demonstrate how intermediate configurations and rate-determining steps vary with changes in surface structure and reveal the role of the kink in promoting CO2 reduction to methanol through electronic structure calculation. Moreover, it is found that the predominant synthetic pathway for CH3OH from CO2 involves the reverse water gas shift and CO hydrogenation, rather than the formate route, on Cu/ZnO surfaces with kinks.
催化二氧化碳加氢制甲醇为二氧化碳的循环利用提供了一条前景广阔的途径，从而提高了环境的可持续性。Cu/ZnO 早已被确定为该反应最有效的异相催化剂之一，但对其反应机理和活性位点的详细了解仍不全面。最近的研究进展凸显了缺陷在提高催化剂性能方面的关键作用，如 ZnCu 台阶和铜表面的堆叠断层。在此，我们通过对六种模型的第一原理表面模拟来探讨这一概念，这些模型具有不同的铜锌组合和特定的配位环境，并处于现实条件下。结果表明，具有扭结缺陷的 Cu/ZnO 催化剂，而不是表面 ZnCu 合金，在甲醇合成中表现出最佳活性。具体而言，研究结果表明了中间构型和速率决定步骤如何随表面结构的变化而变化，并通过电子结构计算揭示了扭结在促进 CO2 还原成甲醇过程中的作用。此外，研究还发现，在具有扭结的 Cu/ZnO 表面上，由 CO2 生成 CH3OH 的主要合成途径涉及反向水气变换和 CO 加氢，而不是甲酸盐途径。
{"title":"Thermal Methanol Synthesis from CO2 Using Cu/ZnO Catalysts: Insights from First-Principles Calculations","authors":"Cong Xi, Yixin Nie, Hongjuan Wang, Cunku Dong, Jiuhui Han, Xi-Wen Du","doi":"10.1002/sstr.202400345","DOIUrl":"https://doi.org/10.1002/sstr.202400345","url":null,"abstract":"Catalytic hydrogenation of carbon dioxide to methanol offers a promising avenue for recycling CO<sub>2</sub>, enhancing environmental sustainability. Cu/ZnO has long been identified as one of the most effective heterogeneous catalysts for this reaction, yet the detailed understanding of its reaction mechanism and active sites remains incomplete. Recent advances have highlighted the critical role of defects, such as ZnCu steps and stacking faults on Cu surfaces, in enhancing catalyst performance. Here this concept is explored through first-principles surface simulations of six models, featuring diverse Cu–Zn combinations and specific coordination environments under realistic conditions. It is revealed that Cu/ZnO catalysts with kink defects, rather than surface ZnCu alloys, exhibit optimal activity for methanol synthesis. Specifically, the findings demonstrate how intermediate configurations and rate-determining steps vary with changes in surface structure and reveal the role of the kink in promoting CO<sub>2</sub> reduction to methanol through electronic structure calculation. Moreover, it is found that the predominant synthetic pathway for CH<sub>3</sub>OH from CO<sub>2</sub> involves the reverse water gas shift and CO hydrogenation, rather than the formate route, on Cu/ZnO surfaces with kinks.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing electrocatalysts that exhibit exceptional activity without relying on noble metals, all while ensuring high efficiency and durability for the oxygen reduction and evolution reactions, poses a challenging yet highly desired task. Monodispersed nanoparticles on a conductive framework through strong metal–support interactions are known to show excellent catalytic performance. Herein, monodispersed iron selenide embedded in a carbon nanotube network is synthesized. Graphitic carbon shells enclosing monodispersed iron selenide address the primary challenge of nanoparticle catalysts—aggregation and corrosion of nanoparticles over repeated oxygen redox reactions. By amplifying the interaction of Fe with carbon nanotubes, the heterogeneous catalyst forms highly active centers for oxygen redox reaction from the coordinated iron atoms, along with conductive iron–nitrogen–carbon nanotube pathways for rapid charge transfer. As a result, the heterogeneous catalyst exhibits superior activity for both oxygen reduction (E1/2 = 0.88 V) and oxygen evolution (η = 360 mV@10 mA cm−2) and excellent stability of negligible degradation over 5000 cycles. The overall catalytic performance surpasses the noble metals. Therefore, rechargeable zinc–air batteries using the heterogeneous catalyst exhibit a high power density of 130.9 mW cm−2, excellent round-trip efficiency of ≈70%, and cycling stability for over 1100 h at 10 mA cm−2.
{"title":"Monodispersed Iron Selenide Nanoparticles United with Carbon Nanotubes for Highly Reversible Zinc–Air Batteries","authors":"Hua Zhang, Tong Zeng, Jiale Ma, Yue Jiang, Yang Huang, Yuxin Cheng, Haifeng Ye, Cuiyun Zeng, Chenghui Zeng, Minshen Zhu, Shuiliang Chen","doi":"10.1002/sstr.202400181","DOIUrl":"https://doi.org/10.1002/sstr.202400181","url":null,"abstract":"Developing electrocatalysts that exhibit exceptional activity without relying on noble metals, all while ensuring high efficiency and durability for the oxygen reduction and evolution reactions, poses a challenging yet highly desired task. Monodispersed nanoparticles on a conductive framework through strong metal–support interactions are known to show excellent catalytic performance. Herein, monodispersed iron selenide embedded in a carbon nanotube network is synthesized. Graphitic carbon shells enclosing monodispersed iron selenide address the primary challenge of nanoparticle catalysts—aggregation and corrosion of nanoparticles over repeated oxygen redox reactions. By amplifying the interaction of Fe with carbon nanotubes, the heterogeneous catalyst forms highly active centers for oxygen redox reaction from the coordinated iron atoms, along with conductive iron–nitrogen–carbon nanotube pathways for rapid charge transfer. As a result, the heterogeneous catalyst exhibits superior activity for both oxygen reduction (<i>E</i><sub>1/2</sub> = 0.88 V) and oxygen evolution (<i>η</i> = 360 mV@10 mA cm<sup>−2</sup>) and excellent stability of negligible degradation over 5000 cycles. The overall catalytic performance surpasses the noble metals. Therefore, rechargeable zinc–air batteries using the heterogeneous catalyst exhibit a high power density of 130.9 mW cm<sup>−2</sup>, excellent round-trip efficiency of ≈70%, and cycling stability for over 1100 h at 10 mA cm<sup>−2</sup>.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Liu Yang, Junchao Wang, Tingting Liu, Hanze He, Xinyu Li, Xinglai Zhang, Jing Li, Song Li, Baodan Liu
Developing an efficient catalyst is the key to selective catalytic reduction (SCR) of NOx by CO (CO-SCR) to simultaneously address the pollution of toxic NOx and CO. Herein, a novel Rh/TiO2/Ti monolithic catalyst is designed and synthesized, featuring Rh species in the form of single atoms (Rh1) and clusters (Rhn). This catalyst overcomes the inhibitory effects of oxygen, achieving low-temperature NO conversion. The investigation substantively contributes insights into the strategic manipulation of active metal components, emphasizing the potential of single-atom/cluster catalysts to enhance efficiency. The Rh/TiO2/Ti catalyst has demonstrated exceptional catalytic efficacy, achieving 100% NO conversion at a low temperature of 190 °C in the presence of oxygen. Additionally, it exhibits remarkable stability and water resistance for practical applications. Moreover, comprehensive characterization confirms that Rh clusters and single-atom sites play an important role in the selective adsorption of NO and CO molecules, promoting the formation of –N2O species and ultimately resulting in the complete conversion of NO and CO to N2 and CO2. This study not only provides valuable guidance for designing high-performance CO-SCR catalysts but also underscores the potential of single atoms/clusters catalytic systems in both fundamental research and industrial catalysis.
开发高效催化剂是一氧化碳选择性催化还原氮氧化物（SCR）的关键，可同时解决有毒氮氧化物和一氧化碳的污染问题。本文设计并合成了一种新型 Rh/TiO2/Ti 整体催化剂，其特点是以单个原子（Rh1）和团簇（Rhn）形式存在的 Rh 物种。这种催化剂克服了氧气的抑制作用，实现了氮氧化物的低温转化。这项研究为活性金属成分的战略操作提供了重要见解，强调了单原子/团簇催化剂提高效率的潜力。Rh/TiO2/Ti 催化剂表现出卓越的催化效率，在有氧气存在的 190 °C 低温条件下实现了 100% 的氮氧化物转化。此外，该催化剂还表现出卓越的稳定性和耐水性，适合实际应用。此外，综合表征证实，Rh 团簇和单原子位点在选择性吸附 NO 和 CO 分子、促进 -N2O 物种的形成以及最终将 NO 和 CO 完全转化为 N2 和 CO2 方面发挥了重要作用。这项研究不仅为设计高性能 CO-SCR 催化剂提供了有价值的指导，而且凸显了单原子/簇催化系统在基础研究和工业催化方面的潜力。
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