Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/...Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/Mo_(2)CT_(x))to enhance the hydrogen evolution reaction(HER)and supercapacitor activities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the reallocation of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo_(2)CT_(x) with high HER activities over a broad range of pH.At a current density of 10 mA cm^(-2),overvoltages of 70 and 81 mV are respectively produced in 0.5 M H_(2)SO_(4)and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg^(-1)at a power density of 15989.6Wkg^(-1).This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.展开更多
Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity...Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity fade and low rate capability.In this work,a composite containing ultrasmall CoS(~7 nm)nanoparticles embedded in heteroatom(N,S,and O)-doped carbon was synthesized by an efficient one-step sulfidation process using a Co(Salen)precursor.The ultrasmall CoS nanoparticles are beneficial for mechanical stability and shortening Na-ions diffusion pathways.Furthermore,the N,S,and O-doped defect-rich carbon provides a robust and highly conductive framework enriched with active sites for sodium storage as well as mitigates volume expansion and polysulfide shuttle.As anode for SIB,CoS@HDC exhibits a high initial capacity of 906 mA h g^(-1)at 100 mA g^(-1)and a stable long-term cycling life with over 1000 cycles at 500 mA g^(-1),showing a reversible capacity of 330 mA h g^(-1).Meanwhile,the CoS@HDC anode is proven to maintain its structural integrity and compositional reversibility during cycling.Furthermore,Na-ion full batteries based on the CoS@HDC anode and Na_(3)V_(2)(PO_(4))_(3)cathode demonstrate a stable cycling behavior with a reversible specific capacity of~200 m A h g^(-1)at least for 100 cycles.Moreover,advanced synchrotron operando X-ray diffraction,ex-situ X-ray absorption spectroscopy,and comprehensive electrochemical tests reveal the structural transformation and the Co coordination chemistry evolution of the CoS@HDC during cycling,providing fundamental insights into the sodium storage mechanism.展开更多
Banana peel-derived porous carbon(BPPC) was prepared from banana peel and used as an adsorbent for methyl orange(MO) wastewater removal. BPPC-MO50 is a N,S-doped BPPC obtained via secondary carbonization. The BPPC-MO5...Banana peel-derived porous carbon(BPPC) was prepared from banana peel and used as an adsorbent for methyl orange(MO) wastewater removal. BPPC-MO50 is a N,S-doped BPPC obtained via secondary carbonization. The BPPC-MO50 exhibited a high specific surface area of1774.3 m^2/g. Heteroatom-doped porous carbon(PC) was successfully synthesized from the BPPC absorbed MO at high temperature and used for oxygen reduction. The BPPC-MO50 displayed the highest ORR onset potential among all carbon-based electrocatalysts, i.e., 0.93 V vs.reversible hydrogen electrode(RHE). This is the first report to describe porous carbon-activated materials from agriculture and forestry waste that is used for adsorption of dyes from wastewater via an enhanced heteroatom(N,S) content. These results may contribute to the sustainable development of dye wastewater treatment by transforming saturated PC into an effective material and has potential applications in fuel cells or as energy sources.展开更多
The increasing energy consumption and environmental concerns due to burning fossil fuel are key drivers for the development of effective energy storage systems based on innovative materials.Among these materials,graph...The increasing energy consumption and environmental concerns due to burning fossil fuel are key drivers for the development of effective energy storage systems based on innovative materials.Among these materials,graphene has emerged as one of the most promising due to its chemical,electrical,and mechanical properties.Heteroatom doping has been proven as an effective way to tailor the properties of graphene and render its potential use for energy storage devices.In this view,we review the recent developments in the synthesis and applications of heteroatom-doped graphene in supercapacitors and lithium ion batteries.展开更多
基金supported by the National Natural Science Foundation of China(21905069)the Shenzhen Science and Technology Innovation Committee(JCYJ20180507183907224 and KQTD20170809110344233)the Economic,Trade and Information Commission of Shenzhen Municipality through the Graphene Manufacture Innovation Center(201901161514)。
文摘Vacancy engineering is a useful methodology in the development of catalysts and electrode materials.Herein,we report the introduction of Se-vacancy pairs in heteroatom-doped(N,B,and F)CoSe/Mo_(2)CT_(x) MXene(NBF-CoSe/Mo_(2)CT_(x))to enhance the hydrogen evolution reaction(HER)and supercapacitor activities via an ionic liquid-mediated method.Se vacancy pairs and heteroatom doping enable the reallocation of local electron states and add active sites,improving the electrochemical activity of NBF-CoSe/Mo_(2)CT_(x) with high HER activities over a broad range of pH.At a current density of 10 mA cm^(-2),overvoltages of 70 and 81 mV are respectively produced in 0.5 M H_(2)SO_(4)and 1 M KOH.The optimal structure also exhibits outstanding electrochemical performance in an asymmetric supercapacitor with an energy density of 34.2 Wh kg^(-1)at a power density of 15989.6Wkg^(-1).This study opens new avenues for the introduction of Se vacancies and heteroatom doping to improve the application performance.
基金the financial support from China Scholarship Council(202108080263)Financial support by the Federal Ministry of Education and Research(BMBF)under the project“He Na”(03XP0390C)+1 种基金the German Research Foundation(DFG)under the joint German-Russian DFG project“KIBSS”(448719339)are acknowledgedthe financial support from the Federal Ministry of Education and Research(BMBF)under the project“Ka Si Li”(03XP0254D)in the competence cluster“Excell Batt Mat”。
文摘Transition metal sulfides have been regarded as promising anode materials for sodium-ion batteries(SIB).However,they face the challenges of poor electronic conductivity and large volume change,which result in capacity fade and low rate capability.In this work,a composite containing ultrasmall CoS(~7 nm)nanoparticles embedded in heteroatom(N,S,and O)-doped carbon was synthesized by an efficient one-step sulfidation process using a Co(Salen)precursor.The ultrasmall CoS nanoparticles are beneficial for mechanical stability and shortening Na-ions diffusion pathways.Furthermore,the N,S,and O-doped defect-rich carbon provides a robust and highly conductive framework enriched with active sites for sodium storage as well as mitigates volume expansion and polysulfide shuttle.As anode for SIB,CoS@HDC exhibits a high initial capacity of 906 mA h g^(-1)at 100 mA g^(-1)and a stable long-term cycling life with over 1000 cycles at 500 mA g^(-1),showing a reversible capacity of 330 mA h g^(-1).Meanwhile,the CoS@HDC anode is proven to maintain its structural integrity and compositional reversibility during cycling.Furthermore,Na-ion full batteries based on the CoS@HDC anode and Na_(3)V_(2)(PO_(4))_(3)cathode demonstrate a stable cycling behavior with a reversible specific capacity of~200 m A h g^(-1)at least for 100 cycles.Moreover,advanced synchrotron operando X-ray diffraction,ex-situ X-ray absorption spectroscopy,and comprehensive electrochemical tests reveal the structural transformation and the Co coordination chemistry evolution of the CoS@HDC during cycling,providing fundamental insights into the sodium storage mechanism.
基金supported by the Doctor Foundation of Bingtuan (No.2014BB004)National Natural Science Foundation of China (U130329)+1 种基金the Program for Changjiang Scholars, Innovative Research Team in University (No. IRT_15R46)the Program of Science and Technology Innovation Team in Bingtuan (No. 2015BD003)
文摘Banana peel-derived porous carbon(BPPC) was prepared from banana peel and used as an adsorbent for methyl orange(MO) wastewater removal. BPPC-MO50 is a N,S-doped BPPC obtained via secondary carbonization. The BPPC-MO50 exhibited a high specific surface area of1774.3 m^2/g. Heteroatom-doped porous carbon(PC) was successfully synthesized from the BPPC absorbed MO at high temperature and used for oxygen reduction. The BPPC-MO50 displayed the highest ORR onset potential among all carbon-based electrocatalysts, i.e., 0.93 V vs.reversible hydrogen electrode(RHE). This is the first report to describe porous carbon-activated materials from agriculture and forestry waste that is used for adsorption of dyes from wastewater via an enhanced heteroatom(N,S) content. These results may contribute to the sustainable development of dye wastewater treatment by transforming saturated PC into an effective material and has potential applications in fuel cells or as energy sources.
文摘The increasing energy consumption and environmental concerns due to burning fossil fuel are key drivers for the development of effective energy storage systems based on innovative materials.Among these materials,graphene has emerged as one of the most promising due to its chemical,electrical,and mechanical properties.Heteroatom doping has been proven as an effective way to tailor the properties of graphene and render its potential use for energy storage devices.In this view,we review the recent developments in the synthesis and applications of heteroatom-doped graphene in supercapacitors and lithium ion batteries.
