Research on hard carbon(HC)anodes for sodium-ion storage has focused on sodium storage mechanisms in both the high-potential slope and low-potential plateau regions,with the latter being particularly critical for enha...Research on hard carbon(HC)anodes for sodium-ion storage has focused on sodium storage mechanisms in both the high-potential slope and low-potential plateau regions,with the latter being particularly critical for enhancing energy density.Herein,a novel approach that combines ion exchange with low-temperature pyrolysis is presented to develop a closed-pore structure within HC.Leveraging a hard-template design,this approach precisely controls pore distribution and morphology,leading to a significant increase in the proportion of closed pores.In-situ characterization,density functional theory(DFT)calculations,and multi-scale simulations are used to investigate the micropore filling by sodium ions and the formation of clusters within the closed-pore structure.The findings underscore the crucial role of these structural features in enhancing electrochemical performance and offer a quantitative framework for the design of advanced HC materials.The optimized HC demonstrates a high reversible capacity of 413 mAh g^(-1)at a current density of 0.1 A g^(-1),excellent rate capability,and exceptional stability over 10,000 cycles.This study offers valuable insights into sodium-ion storage mechanisms in closed-pore HC and lays the groundwork for developing efficient and durable sodium storage materials.展开更多
Mesoporous La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） perovskite oxides were synthesized via hard-templating with ordered mesoporous silica SBA-15 as the template. The as-prepared samples were characterized by XRD, SE...Mesoporous La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） perovskite oxides were synthesized via hard-templating with ordered mesoporous silica SBA-15 as the template. The as-prepared samples were characterized by XRD, SEM, AFM, BET, and XPS and the catalytic activity was tested for CO oxidation. The wide-angle XRD patterns showed that La0.8Sr0.2MnO3＋σ perovskite was formed. The SEM and AFM analyses exhibited that La0.8Sr0.2MnO3＋σ by hard-templating method had much smaller particle size（18 nm） than that（40 nm） by the sol-gel method. The perovskite-type oxides La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） also displayed a higher BET surface area from 70 to 143.7 m^2/g and a disordered mesostructure from nitrogen sorption analysis, as well as a small-angle XRD pattern. Moreover, the La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） perovskite exhibited a much higher activity in CO oxidation than the conventional La0.8Sr0.2MnO3＋σ perovskite. Further analysis by the means of XPS techniques indicated that the existence of high content of Oads/Olatt species contributed to the high activity.展开更多
Mesoporous silicas such as MCM-41 and SBA-15 possess high surface areas, ordered nanopores, and excellent thermal stability, and have been often used as catalyst supports. Although mesoporous metal oxides have lower s...Mesoporous silicas such as MCM-41 and SBA-15 possess high surface areas, ordered nanopores, and excellent thermal stability, and have been often used as catalyst supports. Although mesoporous metal oxides have lower surface areas compared to mesoporous silicas, they generally have more diversified functionalities. Mesopor- ous metal oxides can be synthesized via a soft-templating or hard-templating approach, and these materials have recently found some applications in environmental cata- lysis, such as CO oxidation, N20 decomposition, and elimination of organic pollutants. In this review, we summarize the synthesis of mesoporous transition metal oxides using mesoporous silicas as hard templates, high- light the application of these materials in environmental catalysis, and furnish some prospects for future develop- ment.展开更多
A unique“integrated hard-templating strategy”is described for facile synthesis of a carbonaceous material with a novel three-dimensional(3 D)branched hollow architecture.A set of steps,including template formation,s...A unique“integrated hard-templating strategy”is described for facile synthesis of a carbonaceous material with a novel three-dimensional(3 D)branched hollow architecture.A set of steps,including template formation,surface coating and template removal,all occur in a spontaneous and orderly manner in the one-pot hydrothermal process.Investigations on structural evolution during the process reveal that pre-synthesized zeolitic imidazolate framework-8(ZIF-8)nanoparticles are first dissociated and then self-assembled into 3 D branched superstructures of ZnO as templates.Initial self-assembly is followed by coating of the glucose-derived carbonaceous materials and etching of interior ZnO by organic acids released in situ by hydrolysis of glucose.The 3 D-branched hollow architecture is shown to greatly enhance supercapacitor performance.The research described here provides guidance into the development of strategies for complex hollow carbonaceous architectures for a variety of potential applications.展开更多
基金supported by the National Natural Science Foundation of China(22269020,U23A20582,42167068)the Outstanding Youth Fund of Gansu Province(20JR5RA539)+1 种基金the Gansu Province Higher Education Industry Support Plan Project(2023CYZC-17)2024 Major Cultivation Project for University Research and Innovation Platforms(2024CXPT-10)。
文摘Research on hard carbon(HC)anodes for sodium-ion storage has focused on sodium storage mechanisms in both the high-potential slope and low-potential plateau regions,with the latter being particularly critical for enhancing energy density.Herein,a novel approach that combines ion exchange with low-temperature pyrolysis is presented to develop a closed-pore structure within HC.Leveraging a hard-template design,this approach precisely controls pore distribution and morphology,leading to a significant increase in the proportion of closed pores.In-situ characterization,density functional theory(DFT)calculations,and multi-scale simulations are used to investigate the micropore filling by sodium ions and the formation of clusters within the closed-pore structure.The findings underscore the crucial role of these structural features in enhancing electrochemical performance and offer a quantitative framework for the design of advanced HC materials.The optimized HC demonstrates a high reversible capacity of 413 mAh g^(-1)at a current density of 0.1 A g^(-1),excellent rate capability,and exceptional stability over 10,000 cycles.This study offers valuable insights into sodium-ion storage mechanisms in closed-pore HC and lays the groundwork for developing efficient and durable sodium storage materials.
文摘Mesoporous La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） perovskite oxides were synthesized via hard-templating with ordered mesoporous silica SBA-15 as the template. The as-prepared samples were characterized by XRD, SEM, AFM, BET, and XPS and the catalytic activity was tested for CO oxidation. The wide-angle XRD patterns showed that La0.8Sr0.2MnO3＋σ perovskite was formed. The SEM and AFM analyses exhibited that La0.8Sr0.2MnO3＋σ by hard-templating method had much smaller particle size（18 nm） than that（40 nm） by the sol-gel method. The perovskite-type oxides La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） also displayed a higher BET surface area from 70 to 143.7 m^2/g and a disordered mesostructure from nitrogen sorption analysis, as well as a small-angle XRD pattern. Moreover, the La0.8Sr0.2MnO3＋σ/z SBA-15（z = 1, 2, 4） perovskite exhibited a much higher activity in CO oxidation than the conventional La0.8Sr0.2MnO3＋σ perovskite. Further analysis by the means of XPS techniques indicated that the existence of high content of Oads/Olatt species contributed to the high activity.
文摘Mesoporous silicas such as MCM-41 and SBA-15 possess high surface areas, ordered nanopores, and excellent thermal stability, and have been often used as catalyst supports. Although mesoporous metal oxides have lower surface areas compared to mesoporous silicas, they generally have more diversified functionalities. Mesopor- ous metal oxides can be synthesized via a soft-templating or hard-templating approach, and these materials have recently found some applications in environmental cata- lysis, such as CO oxidation, N20 decomposition, and elimination of organic pollutants. In this review, we summarize the synthesis of mesoporous transition metal oxides using mesoporous silicas as hard templates, high- light the application of these materials in environmental catalysis, and furnish some prospects for future develop- ment.
基金supported by the National Natural Science Foundation of China(21872105,22072107)the Natural Science Foundation of Zhejiang Province(LQ20B030001 and LY20E020002)。
文摘A unique“integrated hard-templating strategy”is described for facile synthesis of a carbonaceous material with a novel three-dimensional(3 D)branched hollow architecture.A set of steps,including template formation,surface coating and template removal,all occur in a spontaneous and orderly manner in the one-pot hydrothermal process.Investigations on structural evolution during the process reveal that pre-synthesized zeolitic imidazolate framework-8(ZIF-8)nanoparticles are first dissociated and then self-assembled into 3 D branched superstructures of ZnO as templates.Initial self-assembly is followed by coating of the glucose-derived carbonaceous materials and etching of interior ZnO by organic acids released in situ by hydrolysis of glucose.The 3 D-branched hollow architecture is shown to greatly enhance supercapacitor performance.The research described here provides guidance into the development of strategies for complex hollow carbonaceous architectures for a variety of potential applications.
