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。
{"title":"Synergistic Catalysis of Rh Single-Atom and Clusters Supported on TiO2 Nanosheet Array for Highly Efficient Removal of CO and NOx","authors":"Liu Yang, Junchao Wang, Tingting Liu, Hanze He, Xinyu Li, Xinglai Zhang, Jing Li, Song Li, Baodan Liu","doi":"10.1002/sstr.202400230","DOIUrl":"https://doi.org/10.1002/sstr.202400230","url":null,"abstract":"Developing an efficient catalyst is the key to selective catalytic reduction (SCR) of NO<sub><i>x</i></sub> by CO (CO-SCR) to simultaneously address the pollution of toxic NO<sub><i>x</i></sub> and CO. Herein, a novel Rh/TiO<sub>2</sub>/Ti monolithic catalyst is designed and synthesized, featuring Rh species in the form of single atoms (Rh<sub>1</sub>) and clusters (Rh<sub><i>n</i></sub>). 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/TiO<sub>2</sub>/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 –N<sub>2</sub>O species and ultimately resulting in the complete conversion of NO and CO to N<sub>2</sub> and CO<sub>2</sub>. 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.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260174","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}
The trade-off between gas permeability and resistance to plasma leakage imposes a great challenge for the practical use of membranes in extracorporeal membrane oxygenation (ECMO). Herein, a polypropylene (PP) hollow-fiber composite membrane is fabricated by simply grafting mesoporous silica nanoparticles onto the commercial PP membrane, which shows a significantly enhanced gas permeability and superior resistance to plasma leakage. The performance metrics such as gas permeability, bubble point, surface hydrophobicity, and plasma leakage resistance are largely influenced by the type of functional groups on the silica nanoparticles (hydroxyl, vinyl, or trifluoropropyl). It is shown that the trifluoropropyl-group functionalized mesoporous silica nanoparticle grafted composite membrane demonstrates a superior performance than the commercial ECMO membrane of poly(4-methyl-1-pentene) (PMP). The bubble point is greatly elevated from 0.36 to 1.20 MPa while the decrease in gas flux is negligible within 4%. And the leakage resistance time is significantly prolonged from 600 to 4140 min. The gained benefits are originated from the enhanced mass transfer area and diminished surface pores of the composite membrane are grafted with the mesoporous nanoparticles. The high-performance PP-based composite membranes are cost-effective and promising in practical applications of ECMO.
{"title":"Mesoporous Silica Nanoparticle Grafted Polypropylene Membrane toward Long-Term Efficient Oxygenation","authors":"Aoxing Feng, Yakai Lin, Dayin Sun, Fangyu Wu, Huanhuan Wu, Yuanhui Tang, Fanchen Zhang, Wei Jia, Lixin Yu, Xiaolin Wang, Zhenzhong Yang","doi":"10.1002/sstr.202400324","DOIUrl":"https://doi.org/10.1002/sstr.202400324","url":null,"abstract":"The trade-off between gas permeability and resistance to plasma leakage imposes a great challenge for the practical use of membranes in extracorporeal membrane oxygenation (ECMO). Herein, a polypropylene (PP) hollow-fiber composite membrane is fabricated by simply grafting mesoporous silica nanoparticles onto the commercial PP membrane, which shows a significantly enhanced gas permeability and superior resistance to plasma leakage. The performance metrics such as gas permeability, bubble point, surface hydrophobicity, and plasma leakage resistance are largely influenced by the type of functional groups on the silica nanoparticles (hydroxyl, vinyl, or trifluoropropyl). It is shown that the trifluoropropyl-group functionalized mesoporous silica nanoparticle grafted composite membrane demonstrates a superior performance than the commercial ECMO membrane of poly(4-methyl-1-pentene) (PMP). The bubble point is greatly elevated from 0.36 to 1.20 MPa while the decrease in gas flux is negligible within 4%. And the leakage resistance time is significantly prolonged from 600 to 4140 min. The gained benefits are originated from the enhanced mass transfer area and diminished surface pores of the composite membrane are grafted with the mesoporous nanoparticles. The high-performance PP-based composite membranes are cost-effective and promising in practical applications of ECMO.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260161","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}
Junho Sung, Minji Kim, Sein Chung, Yongchan Jang, Soyoung Kim, Min-Seok Kang, Hee-Young Lee, Joonhee Kang, Donghwa Lee, Wonho Lee, Eunho Lee
Electrolyte-gated organic synaptic transistors (EGOSTs) have shed light on their potential in bioelectronics and neuromorphic computing. Numerous research have been studied to modulate their electrochemical doping performance and formulate a simple approach to control iontronics through the side-chain modulations; however, the effects of alkyl groups as side moieties have not been studied in detail on EGOSTs. Herein, the structural and electrical properties of conjugated polymers are systematically controlled through copolymerization with two different-alkyl group-derived monomers for enhancing the nonvolatile characteristics of EGOSTs. The relationships between crystal orientation and electrochemical doping states of conjugated copolymers, which varied with the different copolymerization ratios, are revealed. Also, the behavior of biological synapses, including paired-pulse facilitation, spike timing-dependent plasticity, and long-term potentiation/depression, are successfully simulated. In this study, new avenues are opened for the implementation of neuromorphic devices through side-chain engineering by showing that the alkyl chain modulates the doping performance.
{"title":"Modulating Alkyl Groups in Copolymer to Control Ion Transport in Electrolyte-Gated Organic Transistors for Neuromorphic Computing","authors":"Junho Sung, Minji Kim, Sein Chung, Yongchan Jang, Soyoung Kim, Min-Seok Kang, Hee-Young Lee, Joonhee Kang, Donghwa Lee, Wonho Lee, Eunho Lee","doi":"10.1002/sstr.202400319","DOIUrl":"https://doi.org/10.1002/sstr.202400319","url":null,"abstract":"Electrolyte-gated organic synaptic transistors (EGOSTs) have shed light on their potential in bioelectronics and neuromorphic computing. Numerous research have been studied to modulate their electrochemical doping performance and formulate a simple approach to control iontronics through the side-chain modulations; however, the effects of alkyl groups as side moieties have not been studied in detail on EGOSTs. Herein, the structural and electrical properties of conjugated polymers are systematically controlled through copolymerization with two different-alkyl group-derived monomers for enhancing the nonvolatile characteristics of EGOSTs. The relationships between crystal orientation and electrochemical doping states of conjugated copolymers, which varied with the different copolymerization ratios, are revealed. Also, the behavior of biological synapses, including paired-pulse facilitation, spike timing-dependent plasticity, and long-term potentiation/depression, are successfully simulated. In this study, new avenues are opened for the implementation of neuromorphic devices through side-chain engineering by showing that the alkyl chain modulates the doping performance.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260163","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}
Ti3C2, one typical MXene, has great potential to be coupled with various transition metals. Herein, a novel and effective catalyst is developed by synergistically loading VCoCOx onto Ti3C2-modified nickel foam (VCoCOx–Ti3C2@NF). Field emission scanning electron microscope and high-resolution transmission electron microscopy are employed to characterize the morphology and structure. As expected, the catalyst optimized by response surface methodology attains overpotentials of 290 and 64 mV and Tafel slopes of 82 and 79 mV dec−1 for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. By using the bifunctional VCoCOx–Ti3C2@NF catalyst, the water splitting current density achieves 10 mA cm−2 in 1.0 mol L−1 KOH electrolyte at cell voltage of 1.52 V, comparable with the noble metal electrolyzer Pt@C@NF||RuO2@NF (1.57 V). Furthermore, the resulting catalyst exhibits excellent cycling durability after 120 h of continuous catalysis, which retains 103.8% and 105.4% of potential (V vs reversible hydrogen electrode) for OER and HER, respectively. Density functional theory calculation reveals that the Gibbs free energy barriers for the OER and HER intermediates are reduced due to the integration of VCoCOx with Ti3C2@NF. The fabricated VCoCOx–Ti3C2@NF catalyst is a promising electrochemical material for clean energy production.
Ti3C2 是一种典型的 MXene，具有与各种过渡金属耦合的巨大潜力。本文通过在 Ti3C2 改性泡沫镍（VCoCOx-Ti3C2@NF）上协同负载 VCoCOx，开发了一种新型有效的催化剂。利用场发射扫描电子显微镜和高分辨率透射电子显微镜对其形态和结构进行了表征。正如预期的那样，通过响应面方法优化的催化剂在氧进化反应（OER）和氢进化反应（HER）中的过电位分别为 290 和 64 mV，Tafel 斜率分别为 82 和 79 mV dec-1。通过使用双功能 VCoCOx-Ti3C2@NF 催化剂，在 1.0 mol L-1 KOH 电解液中，电池电压为 1.52 V 时，水分离电流密度达到 10 mA cm-2，与贵金属电解器 Pt@C@NF||RuO2@NF (1.57 V) 不相上下。此外，所产生的催化剂在连续催化 120 小时后表现出卓越的循环耐久性，在 OER 和 HER 中分别保持了 103.8% 和 105.4% 的电位（V vs 可逆氢电极）。密度泛函理论计算表明，由于 VCoCOx 与 Ti3C2@NF 的结合，OER 和 HER 中间产物的吉布斯自由能垒有所降低。所制备的 VCoCOx-Ti3C2@NF 催化剂是一种很有前景的清洁能源生产电化学材料。
{"title":"Clustered VCoCOx Nanosheets Anchored on MXene–Ti3C2@NF as a Superior Bifunctional Electrocatalyst for Alkaline Water Splitting","authors":"Wenxin Wang, Yourong Tao, Lulu Xu, Ruilong Ye, Peng Yang, Junjie Zhu, Liping Jiang, Xingcai Wu","doi":"10.1002/sstr.202400278","DOIUrl":"https://doi.org/10.1002/sstr.202400278","url":null,"abstract":"Ti<sub>3</sub>C<sub>2</sub>, one typical MXene, has great potential to be coupled with various transition metals. Herein, a novel and effective catalyst is developed by synergistically loading VCoCO<i>x</i> onto Ti<sub>3</sub>C<sub>2</sub>-modified nickel foam (VCoCO<i>x</i>–Ti<sub>3</sub>C<sub>2</sub>@NF). Field emission scanning electron microscope and high-resolution transmission electron microscopy are employed to characterize the morphology and structure. As expected, the catalyst optimized by response surface methodology attains overpotentials of 290 and 64 mV and Tafel slopes of 82 and 79 mV dec<sup>−1</sup> for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), respectively. By using the bifunctional VCoCO<i>x</i>–Ti<sub>3</sub>C<sub>2</sub>@NF catalyst, the water splitting current density achieves 10 mA cm<sup>−2</sup> in 1.0 mol L<sup>−1</sup> KOH electrolyte at cell voltage of 1.52 V, comparable with the noble metal electrolyzer Pt@C@NF||RuO<sub>2</sub>@NF (1.57 V). Furthermore, the resulting catalyst exhibits excellent cycling durability after 120 h of continuous catalysis, which retains 103.8% and 105.4% of potential (V vs reversible hydrogen electrode) for OER and HER, respectively. Density functional theory calculation reveals that the Gibbs free energy barriers for the OER and HER intermediates are reduced due to the integration of VCoCO<sub><i>x</i></sub> with Ti<sub>3</sub>C<sub>2</sub>@NF. The fabricated VCoCO<i>x</i>–Ti<sub>3</sub>C<sub>2</sub>@NF catalyst is a promising electrochemical material for clean energy production.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"195 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260165","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}
Claire Hotton, Daniel García-Lojo, Evgeny Modin, Rahul Nag, Sergio Gómez-Graña, Jules Marcone, Jaime Gabriel Trazo, Jennifer Bodin, Claire Goldmann, Thomas Bizien, Isabel Pastoriza-Santos, Brigitte Pansu, Jorge Pérez-Juste, Victor Balédent, Cyrille Hamon
Supercrystals, extended lattices of closely packed nanoparticles (NPs), present exciting possibilities for various applications. Under high pressures, typically in the gigapascal (GPa) range, supercrystals undergo significant structural changes, including adjustable interparticle distances, phase transformations, and the formation of new nanostructures through coalescence. While prior research has focused on ligand engineering's impact on supercrystal mechanical response, the influence of NP shape remains unexplored, especially for NPs larger than 10 nm coated with hydrosoluble ligands. This study examines the effects of NP shape on the mechanical properties of supercrystals using high-pressure small-angle X-ray scattering and focused ion beam–scanning electron microscopy tomography. Notably, supercrystals exhibit higher hardness levels compared to previously reported values for gold supercrystals, attributed to the use of larger NPs. Spherical and tetrahedral NPs rearrange before collapsing under pressure, whereas rods and octahedra coalesce without prior structural rearrangement, likely due to their higher packing fraction. Additionally, anisotropic deformation of NP lattices and sintering does not always correlate with deviatoric stresses. These findings refine the understanding of complex processes governing supercrystal structure under high pressure, opening new avenues for NP engineering and advancing plasmonic applications under extreme conditions.
{"title":"Elucidating Supercrystal Mechanics and Nanoparticle Size and Shape Effects under High Pressure","authors":"Claire Hotton, Daniel García-Lojo, Evgeny Modin, Rahul Nag, Sergio Gómez-Graña, Jules Marcone, Jaime Gabriel Trazo, Jennifer Bodin, Claire Goldmann, Thomas Bizien, Isabel Pastoriza-Santos, Brigitte Pansu, Jorge Pérez-Juste, Victor Balédent, Cyrille Hamon","doi":"10.1002/sstr.202400303","DOIUrl":"https://doi.org/10.1002/sstr.202400303","url":null,"abstract":"Supercrystals, extended lattices of closely packed nanoparticles (NPs), present exciting possibilities for various applications. Under high pressures, typically in the gigapascal (GPa) range, supercrystals undergo significant structural changes, including adjustable interparticle distances, phase transformations, and the formation of new nanostructures through coalescence. While prior research has focused on ligand engineering's impact on supercrystal mechanical response, the influence of NP shape remains unexplored, especially for NPs larger than 10 nm coated with hydrosoluble ligands. This study examines the effects of NP shape on the mechanical properties of supercrystals using high-pressure small-angle X-ray scattering and focused ion beam–scanning electron microscopy tomography. Notably, supercrystals exhibit higher hardness levels compared to previously reported values for gold supercrystals, attributed to the use of larger NPs. Spherical and tetrahedral NPs rearrange before collapsing under pressure, whereas rods and octahedra coalesce without prior structural rearrangement, likely due to their higher packing fraction. Additionally, anisotropic deformation of NP lattices and sintering does not always correlate with deviatoric stresses. These findings refine the understanding of complex processes governing supercrystal structure under high pressure, opening new avenues for NP engineering and advancing plasmonic applications under extreme conditions.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"190 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142269547","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}
Marcin Giza, Aleksey Kozikov, Paula L. Lalaguna, Jake D. Hutchinson, Vaibhav Verma, Benjamin Vella, Rahul Kumar, Nathan Hill, Dumitru Sirbu, Elisabetta Arca, Noel Healy, Rebecca L. Milot, Malcolm Kadodwala, Pablo Docampo
Surface treatment of perovskite materials with their layered counterparts has become an ubiquitous strategy for maximizing device performance. While layered materials confer great benefits to the longevity and long-term efficiency of the resulting device stack via passivation of defects and surface traps, numerous reports have previously demonstrated that these materials evolve under exposure to light and humidity, suggesting that they are not fully stable. Therefore, it is crucial to study the behavior of these materials in isolation and in conditions mimicking a device stack. Here, it is shown that perovskite capping layers templated by a range of cations on top of methylammonium lead iodide devolve in conditions commonly found during perovskite fabrication, such as exposure to light, solvent, and moisture. Photophysical, structural, and morphological studies are used to show that the degradation of these layered perovskites occurs via a self-limiting, pinhole-mediated mechanism. This results in the loss of whole perovskite sheets, from a few monolayers to tens of nanometers of material, until the system stabilizes again as demonstrated for exfoliated flakes of PEA2PbI4. This means that initially targeted structures may have devolved, with clear optimization implications for device fabrication.
{"title":"Illuminating the Devolution of Perovskite Passivation Layers","authors":"Marcin Giza, Aleksey Kozikov, Paula L. Lalaguna, Jake D. Hutchinson, Vaibhav Verma, Benjamin Vella, Rahul Kumar, Nathan Hill, Dumitru Sirbu, Elisabetta Arca, Noel Healy, Rebecca L. Milot, Malcolm Kadodwala, Pablo Docampo","doi":"10.1002/sstr.202400234","DOIUrl":"https://doi.org/10.1002/sstr.202400234","url":null,"abstract":"Surface treatment of perovskite materials with their layered counterparts has become an ubiquitous strategy for maximizing device performance. While layered materials confer great benefits to the longevity and long-term efficiency of the resulting device stack via passivation of defects and surface traps, numerous reports have previously demonstrated that these materials evolve under exposure to light and humidity, suggesting that they are not fully stable. Therefore, it is crucial to study the behavior of these materials in isolation and in conditions mimicking a device stack. Here, it is shown that perovskite capping layers templated by a range of cations on top of methylammonium lead iodide devolve in conditions commonly found during perovskite fabrication, such as exposure to light, solvent, and moisture. Photophysical, structural, and morphological studies are used to show that the degradation of these layered perovskites occurs via a self-limiting, pinhole-mediated mechanism. This results in the loss of whole perovskite sheets, from a few monolayers to tens of nanometers of material, until the system stabilizes again as demonstrated for exfoliated flakes of PEA<sub>2</sub>PbI<sub>4</sub>. This means that initially targeted structures may have devolved, with clear optimization implications for device fabrication.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218403","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}
Hao Ding, Jingyu Hou, Kun Zhai, Xin Gao, Junquan Huang, Feng Ke, Bingchao Yang, Congpu Mu, Fusheng Wen, Jianyong Xiang, Bochong Wang, Tianyu Xue, Anmin Nie, Xiaobing Liu, Lin Wang, Xiang-Feng Zhou, Zhongyuan Liu
High pressure provides a unique tuning method depending on structure modulation to explore the structure–property relationship. Herein, the pressure-induced structural phase transformation and enhanced superconductivity in a layered binary phosphide Sn4P3 are reported. Comprehensive measurements using in situ synchrotron X-Ray diffraction and Raman spectroscopy reveal a structural phase transition with mild distortion of SnP3 building blocks and interlayer shrinkage under high pressure. This differs from a conventional trigonal SnAs(P)3 to square SnAs(P)4 topotactic transition in SnAs(P)-based compound. Through this structure reconstruction under high pressure, electron distribution has been reorganized and phonons have softened, facilitating a high superconducting temperature (Tc) value of 7.8 K at 34.9 GPa, which is almost six times higher than its ambient value. The study introduces a new transition route in layered SnAs/SnP-based intermetallic materials and provides insight into the structural and electronic changes under high pressure for Sn4P3.
{"title":"Pressure-Enhanced Superconductivity and Structural Phase Transition in Layered Sn4P3","authors":"Hao Ding, Jingyu Hou, Kun Zhai, Xin Gao, Junquan Huang, Feng Ke, Bingchao Yang, Congpu Mu, Fusheng Wen, Jianyong Xiang, Bochong Wang, Tianyu Xue, Anmin Nie, Xiaobing Liu, Lin Wang, Xiang-Feng Zhou, Zhongyuan Liu","doi":"10.1002/sstr.202400381","DOIUrl":"https://doi.org/10.1002/sstr.202400381","url":null,"abstract":"High pressure provides a unique tuning method depending on structure modulation to explore the structure–property relationship. Herein, the pressure-induced structural phase transformation and enhanced superconductivity in a layered binary phosphide Sn<sub>4</sub>P<sub>3</sub> are reported. Comprehensive measurements using in situ synchrotron X-Ray diffraction and Raman spectroscopy reveal a structural phase transition with mild distortion of SnP<sub>3</sub> building blocks and interlayer shrinkage under high pressure. This differs from a conventional trigonal SnAs(P)<sub>3</sub> to square SnAs(P)<sub>4</sub> topotactic transition in SnAs(P)-based compound. Through this structure reconstruction under high pressure, electron distribution has been reorganized and phonons have softened, facilitating a high superconducting temperature (<i>T</i><sub>c</sub>) value of 7.8 K at 34.9 GPa, which is almost six times higher than its ambient value. The study introduces a new transition route in layered SnAs/SnP-based intermetallic materials and provides insight into the structural and electronic changes under high pressure for Sn<sub>4</sub>P<sub>3</sub>.","PeriodicalId":21841,"journal":{"name":"Small Structures","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218398","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}
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