同步辐射X射线吸收精细结构(X-ray absorption fine structure,XAFS)光谱是一种基于同步辐射光源的强大分析技术,用于研究材料局域原子或电子结构,XAFS技术广泛应用于物理学、材料学、化学、环境学等领域。整理了近些年XAFS技术在超级...同步辐射X射线吸收精细结构(X-ray absorption fine structure,XAFS)光谱是一种基于同步辐射光源的强大分析技术,用于研究材料局域原子或电子结构,XAFS技术广泛应用于物理学、材料学、化学、环境学等领域。整理了近些年XAFS技术在超级电容器NiCo_(2)O_(4)电极材料研究方面的应用,主要内容包括:(1)X射线吸收近边结构(X-ray absorption near edge structure,XANES)光谱在确定元素价态、电荷转移上的应用;(2)扩展X射线吸收精细结构(extended X-ray absorption fine structure,EXAFS)光谱在确定原子配位结构上的应用;(3)原位XAFS在确定电化学反应机理上的应用。希望帮助科研人员从微观结构角度对NiCo_(2)O_(4)材料电化学储能机理有更深入的理解,促进NiCo_(2)O_(4)电极材料和超级电容器的发展。展开更多
The advancement of planar micro-supercapacitors(PMSCs)for micro-electromechanical systems(MEMS)has been significantly hindered by the challenge of achieving high energy and power densities.This study addresses this is...The advancement of planar micro-supercapacitors(PMSCs)for micro-electromechanical systems(MEMS)has been significantly hindered by the challenge of achieving high energy and power densities.This study addresses this issue by leveraging screen-printing technology to fabricate high-performance PMSCs using innovative composite ink.The ink,a synergistic blend of few-layer graphene(Gt),carbon black(CB),and NiCo_(2)O_(4),was meticulously mixed to form a conductive and robust coating that enhanced the capacitive performance of the PMSCs.The optimized ink formulation and printing process result in a micro-supercapacitor with an exceptional areal capacitance of 18.95 mF/cm^(2)and an areal energy density of 2.63μW·h/cm^(2)at a current density of 0.05 mA/cm^(2),along with an areal power density of 0.025 mW/cm^(2).The devices demonstrated impressive durability with a capacitance retention rate of 94.7%after a stringent 20000-cycle test,demonstrating their potential for long-term applications.Moreover,the PMSCs displayed excellent mechanical flexibility,with a capacitance decrease of only 3.43%after 5000 bending cycles,highlighting their suitability for flexible electronic devices.The ease of integrating these PMSCs into series and parallel configurations for customized power further underscores their practicality for integrated power supply solutions in various technologies.展开更多
Semiconductor photocatalysis has been considered as a potential technology for the removal of organic dyes from wastewater.The development of photocatalysts with high stability and strong catalytic activity is the mos...Semiconductor photocatalysis has been considered as a potential technology for the removal of organic dyes from wastewater.The development of photocatalysts with high stability and strong catalytic activity is the most important in application.Visible-light-induced NiCo_(2)O_(4)@Co_(3)O_(4) core/shell heterojunctions were synthesized via a sol-gel method in this paper.Compared to bare NiCo_(2)O_(4) and Co_(3)O_(4),NiCo_(2)O_(4)@Co_(3)O_(4) showed a remarkably enhanced removal rate towards congo red(CR)degradation with 98.4%of the removal rate to CR at 120 min under irradiation.The excellent performance of NiCo_(2)O_(4)@Co_(3)O_(4) benefits from the effective separation of photogenerated electron-holes by forming a heterojunction,and the rapid transfer efficiency of photo-generated charge carriers results from the core/shell architectures.A mechanism that NiCo_(2)O_(4)@Co_(3)O_(4) degrades CR to harmless inorganic substances by h^(+),•O-2 and•OH during the photocatalytic process was proposed.展开更多
文摘同步辐射X射线吸收精细结构(X-ray absorption fine structure,XAFS)光谱是一种基于同步辐射光源的强大分析技术,用于研究材料局域原子或电子结构,XAFS技术广泛应用于物理学、材料学、化学、环境学等领域。整理了近些年XAFS技术在超级电容器NiCo_(2)O_(4)电极材料研究方面的应用,主要内容包括:(1)X射线吸收近边结构(X-ray absorption near edge structure,XANES)光谱在确定元素价态、电荷转移上的应用;(2)扩展X射线吸收精细结构(extended X-ray absorption fine structure,EXAFS)光谱在确定原子配位结构上的应用;(3)原位XAFS在确定电化学反应机理上的应用。希望帮助科研人员从微观结构角度对NiCo_(2)O_(4)材料电化学储能机理有更深入的理解,促进NiCo_(2)O_(4)电极材料和超级电容器的发展。
基金supported by the Shanxi Province Central Guidance Fund for Local Science and Technology Development Project(YDZJSX2024D030)the National Natural Science Foundation of China(22075197,22278290)+2 种基金the Shanxi Province Key Research and Development Program Project(2021020660301013)the Shanxi Provincial Natural Science Foundation of China(202103021224079)the Research and Development Project of Key Core and Common Technology of Shanxi Province(20201102018).
文摘The advancement of planar micro-supercapacitors(PMSCs)for micro-electromechanical systems(MEMS)has been significantly hindered by the challenge of achieving high energy and power densities.This study addresses this issue by leveraging screen-printing technology to fabricate high-performance PMSCs using innovative composite ink.The ink,a synergistic blend of few-layer graphene(Gt),carbon black(CB),and NiCo_(2)O_(4),was meticulously mixed to form a conductive and robust coating that enhanced the capacitive performance of the PMSCs.The optimized ink formulation and printing process result in a micro-supercapacitor with an exceptional areal capacitance of 18.95 mF/cm^(2)and an areal energy density of 2.63μW·h/cm^(2)at a current density of 0.05 mA/cm^(2),along with an areal power density of 0.025 mW/cm^(2).The devices demonstrated impressive durability with a capacitance retention rate of 94.7%after a stringent 20000-cycle test,demonstrating their potential for long-term applications.Moreover,the PMSCs displayed excellent mechanical flexibility,with a capacitance decrease of only 3.43%after 5000 bending cycles,highlighting their suitability for flexible electronic devices.The ease of integrating these PMSCs into series and parallel configurations for customized power further underscores their practicality for integrated power supply solutions in various technologies.
基金Project(2017TP1031)supported by the Hunan Key Laboratory for Rare Earth Functional Materials,ChinaProject(2020JJ4735)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(2018GK4001)supported by Science and Technology Department of Hunan Province Tackling Key Scientific and Technological Problems and Transformation of Major Scientific and Technological Achievements,ChinaProject(CSUZC202126)supported by the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University,China。
文摘Semiconductor photocatalysis has been considered as a potential technology for the removal of organic dyes from wastewater.The development of photocatalysts with high stability and strong catalytic activity is the most important in application.Visible-light-induced NiCo_(2)O_(4)@Co_(3)O_(4) core/shell heterojunctions were synthesized via a sol-gel method in this paper.Compared to bare NiCo_(2)O_(4) and Co_(3)O_(4),NiCo_(2)O_(4)@Co_(3)O_(4) showed a remarkably enhanced removal rate towards congo red(CR)degradation with 98.4%of the removal rate to CR at 120 min under irradiation.The excellent performance of NiCo_(2)O_(4)@Co_(3)O_(4) benefits from the effective separation of photogenerated electron-holes by forming a heterojunction,and the rapid transfer efficiency of photo-generated charge carriers results from the core/shell architectures.A mechanism that NiCo_(2)O_(4)@Co_(3)O_(4) degrades CR to harmless inorganic substances by h^(+),•O-2 and•OH during the photocatalytic process was proposed.
