In this study,for thefirst time,Cu_(2)Nb_(34)O_(78)nanowires were fabricated via an electrospinning technique and exhibited outstanding electrochemical performance as an anode material.The nanowires presented a charge...In this study,for thefirst time,Cu_(2)Nb_(34)O_(78)nanowires were fabricated via an electrospinning technique and exhibited outstanding electrochemical performance as an anode material.The nanowires presented a charge capacity of 279.8 mA h g^(−1)with remarkable long-life stability for 300 cycles(0.037%capacity loss per cycle).Significantly,ex situ X-ray diffraction,ex situ high-resolution transmission electron microscopy,and ex situ X-ray photoelectron spectroscopy were performed to unveil the reaction process and change in the microstructure during charge/discharge cycles in detail.The observed evidence demonstrates that the remarkable Li-storage capability is due to the enhanced contact-specific area and reduced transport path of Cu_(2)Nb_(34)O_(78)nanowires.In addition,the host mechanism is unraveled,in which the contribution of the reversible capacity is discussed based on the Nb^(5+)/Nb^(4+),Nb^(4+)/Nb^(3+)and Cu_(2)+/Cu^(+)redox couples.展开更多
The electrocatalytic activity of catalysts can be significantly enhanced through the utilization of heterogeneous structures.Nevertheless,the optimization of both catalytic activity and durability via heterojunction e...The electrocatalytic activity of catalysts can be significantly enhanced through the utilization of heterogeneous structures.Nevertheless,the optimization of both catalytic activity and durability via heterojunction engineering remains a considerable challenge.In this work,we fabricated electrocatalysts of Co/CoO heterojunctions on a highly porous hollow carbon material.The formation of heterojunctions increases the abundance of accessible active sites and optimizes the electrocatalytic reaction kinetics and reactivity.Thus,the prepared catalysts(Co/CoO@N–C-40)deliver robust and stable bifunctional oxygen electrocatalytic activity during the oxygen reduction/evolution reaction(ORR/OER)process.The performance of rechargeable zinc–air batteries(ZABs)greatly depends on bifunctional oxygen electrocatalysts,which are crucial for efficient charging and discharging processes.Consequently,the Co/CoO@N–C-40-based ZABs have superior cycling stability(750 h)and show a stable energy efficiency of 55.10%at 10 mA cm^(−2)(53.46%after 555 h).This work offers a high-quality oxygen electrocatalyst for ZABs and extends the application of heterogeneous interfacial catalysts in various energy storage and conversion devices.展开更多
Formaldehyde is the most popular and highly toxic indoor pollutants.It is very urgent to develop more sensitive formaldehyde gas sensors with remarkable sensitivity at the ppb level.In this study,for the first time,th...Formaldehyde is the most popular and highly toxic indoor pollutants.It is very urgent to develop more sensitive formaldehyde gas sensors with remarkable sensitivity at the ppb level.In this study,for the first time,the olivine-structured Cd_(2)GeO_(4)was identified as an excellent formaldehyde sensing material.The as-obtained Cd_(2)GeO_(4)and other sensing materials were well characterized by XRD,SEM,TEM,XPS,scanning Kelvin probe and O_(2)temperature-programmed desorption techniques.The sensor based on the asprepared Cd_(2)GeO_(4)exhibits a high response of 14.1,a short response time(about 5 s)towards 10 ppm formaldehyde and a low detection limit of 60 ppb formaldehyde at a relatively low operating temperature of 140℃,benefiting the practical application.We believe that the excellent formaldehyde sensing performance should be attributed to the rich chemisorbed oxygen,the small size and the appropriate Fermi level of Cd_(2)GeO_(4).It can be expected that it will be a promising material for fabricating excellent formaldehyde gas sensors due to its unique sensing characteristics.展开更多
In this study,multi-shelled manganese oxide hollow microspheres with controlled valence were successfully synthesized by varying the Mn-precursor and using an anion-adsorption process for hydrothermal intensification....In this study,multi-shelled manganese oxide hollow microspheres with controlled valence were successfully synthesized by varying the Mn-precursor and using an anion-adsorption process for hydrothermal intensification.Used as the supercapacitor electrode material,the multi-shelled MnO2 hollow microspheres achieved superior specific capacitance(1457 F g^(-1)at the discharge current density of 0.5 A g^(-1))and excellent cycling stability(91.2% retention of the initial capacitance after 4000 cycles),benefiting from the superiorities of these unique hierarchical structures such as increased active sites,shortened ion and electron transport lengths,better contact between the electrolyte and active materials,as well as better protection of interior shells by the exterior shell.展开更多
基金supported by NSAF Joint Fund(U1830106)Science and Technology Innovation 2025 Major Program of Ningbo(2018B10061)K.C.Wong Magna Fund in Ningbo University.
文摘In this study,for thefirst time,Cu_(2)Nb_(34)O_(78)nanowires were fabricated via an electrospinning technique and exhibited outstanding electrochemical performance as an anode material.The nanowires presented a charge capacity of 279.8 mA h g^(−1)with remarkable long-life stability for 300 cycles(0.037%capacity loss per cycle).Significantly,ex situ X-ray diffraction,ex situ high-resolution transmission electron microscopy,and ex situ X-ray photoelectron spectroscopy were performed to unveil the reaction process and change in the microstructure during charge/discharge cycles in detail.The observed evidence demonstrates that the remarkable Li-storage capability is due to the enhanced contact-specific area and reduced transport path of Cu_(2)Nb_(34)O_(78)nanowires.In addition,the host mechanism is unraveled,in which the contribution of the reversible capacity is discussed based on the Nb^(5+)/Nb^(4+),Nb^(4+)/Nb^(3+)and Cu_(2)+/Cu^(+)redox couples.
基金supported by the Hebei Provincial Natural Science Foundation(no.E2024501010)the National Natural Science Foundation of China(no.52374301)+2 种基金the Shijiazhuang Basic Research Project(no.241790667A)the Fundamental Research Funds for the Central Universities(no.N2423054)the Performance Subsidy Fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(no.22567627H).
文摘The electrocatalytic activity of catalysts can be significantly enhanced through the utilization of heterogeneous structures.Nevertheless,the optimization of both catalytic activity and durability via heterojunction engineering remains a considerable challenge.In this work,we fabricated electrocatalysts of Co/CoO heterojunctions on a highly porous hollow carbon material.The formation of heterojunctions increases the abundance of accessible active sites and optimizes the electrocatalytic reaction kinetics and reactivity.Thus,the prepared catalysts(Co/CoO@N–C-40)deliver robust and stable bifunctional oxygen electrocatalytic activity during the oxygen reduction/evolution reaction(ORR/OER)process.The performance of rechargeable zinc–air batteries(ZABs)greatly depends on bifunctional oxygen electrocatalysts,which are crucial for efficient charging and discharging processes.Consequently,the Co/CoO@N–C-40-based ZABs have superior cycling stability(750 h)and show a stable energy efficiency of 55.10%at 10 mA cm^(−2)(53.46%after 555 h).This work offers a high-quality oxygen electrocatalyst for ZABs and extends the application of heterogeneous interfacial catalysts in various energy storage and conversion devices.
基金supported by the National Natural Science Foundation of China(21975093)the Key research and development program of Liaoning provincial(2020JH2/10600003).
文摘Formaldehyde is the most popular and highly toxic indoor pollutants.It is very urgent to develop more sensitive formaldehyde gas sensors with remarkable sensitivity at the ppb level.In this study,for the first time,the olivine-structured Cd_(2)GeO_(4)was identified as an excellent formaldehyde sensing material.The as-obtained Cd_(2)GeO_(4)and other sensing materials were well characterized by XRD,SEM,TEM,XPS,scanning Kelvin probe and O_(2)temperature-programmed desorption techniques.The sensor based on the asprepared Cd_(2)GeO_(4)exhibits a high response of 14.1,a short response time(about 5 s)towards 10 ppm formaldehyde and a low detection limit of 60 ppb formaldehyde at a relatively low operating temperature of 140℃,benefiting the practical application.We believe that the excellent formaldehyde sensing performance should be attributed to the rich chemisorbed oxygen,the small size and the appropriate Fermi level of Cd_(2)GeO_(4).It can be expected that it will be a promising material for fabricating excellent formaldehyde gas sensors due to its unique sensing characteristics.
基金supported financially by the National Natural Science Foundation of China(No.21590795,51572261,51302266,21401199,21201167,51372245,51202248,51472244,51372245,51272165,51541206)the National Science Fund for Distinguished Young Scholars(No.21325105)Australian Research Council(ARC)Discovery Project(No.160104817).
文摘In this study,multi-shelled manganese oxide hollow microspheres with controlled valence were successfully synthesized by varying the Mn-precursor and using an anion-adsorption process for hydrothermal intensification.Used as the supercapacitor electrode material,the multi-shelled MnO2 hollow microspheres achieved superior specific capacitance(1457 F g^(-1)at the discharge current density of 0.5 A g^(-1))and excellent cycling stability(91.2% retention of the initial capacitance after 4000 cycles),benefiting from the superiorities of these unique hierarchical structures such as increased active sites,shortened ion and electron transport lengths,better contact between the electrolyte and active materials,as well as better protection of interior shells by the exterior shell.
