High-performance nonprecious electrocatalysts toward water splitting are in high demand but currently their development is still challenging.Here,we demonstrate that heterometallic two-dimensional(2D)metal phosphonate...High-performance nonprecious electrocatalysts toward water splitting are in high demand but currently their development is still challenging.Here,we demonstrate that heterometallic two-dimensional(2D)metal phosphonates with improved catalytic activity and durability could be realized through defect engineering and heterometallic doping.The optimal electrocatalyst QAU-1-FeNi(1:2)exhibits prominent oxygen evolution reaction(OER)activity in alkaline electrolytes with a very low overpotential of 230 mV at 10 mA cm^(-2)and a small Tafel slope of 47 mV dec^(-1)and is superior to the commercial electrocatalyst IrO_(2).Meanwhile,QAU-1-FeNi(1:2)shows outstanding stability for at least 20 hours and continuous CV scanning for more than 2000 cycles.In this work,a novel strategy of optimization of phosphonate based electrocatalysts by defect engineering and heterometallic doping has been proposed,which has significant potential in the preparation of catalysts for energy conversion applications.展开更多
Currently,the investigation of two-dimensional(2D)crystalline materials,notably transition metal tungsten-based sulfides,is scarcely reported in the wide-temperature field.Thus,tungsten sulphide encapsulated in a sulp...Currently,the investigation of two-dimensional(2D)crystalline materials,notably transition metal tungsten-based sulfides,is scarcely reported in the wide-temperature field.Thus,tungsten sulphide encapsulated in a sulphurized polyacrylonitrile composite(WS_(2)-SPAN)was prepared using an electrospinning technology combined with a sulphuration process.By virtue of the abundant S vacancies and in situ N doping,the WS_(2)-SPAN composite shows an impressively ultralong lifespan and stable circulation capacity over a wide temperature range(−15-50℃).For sodium storage,the WS_(2)-SPAN-2 composite delivers optimized high-rate performance and ultrastable cycling properties(464 mA h g^(-1)/450 cycles at 0.5 A g^(-1);354 mA h g^(-1)/1400 cycles at 2 A g^(-1),190 mA h g^(-1)/12000 cycles at 5 A g^(-1);129 mA h g^(-1)/18000 cycles at 10 A g^(-1),surpassing previously reported WS_(2)-based anodes for SIBs).This is paired with an Na_(3)V_(2)(PO_(4))_(3)cathode,which exhibits excellent storage capacity(241 mA h g^(-1)/200 cycles at 0.5 A g^(-1)).Potassium storage also demonstrates admirable performance(362 mA h g^(-1)/100 cycles at 0.1 A g^(-1);278 mA h g^(-1)/3000 cycles at 1 A g^(-1)).In addition,a detailed illustration of the electrochemical storage mechanism of WS_(2)-SPAN composites is presented through theoretical calculations and electrochemical dynamics.Thus,the present investigation provides new insights into the preparation of novel WS_(2)-based anodes for sodium/potassium-ion batteries with ultralong lifespans and wide-temperature workability.展开更多
基金financial support from the Natural Science Foundation of Shandong Province(ZR2020MB015)the Qingdao Science and Technology Program(No.19-6-1-43-nsh)+1 种基金the Advanced Talents Foundation of Qingdao Agricultural University(663/1118024)the Postgraduate Innovation Program of Qingdao Agricultural University(QNYCX20018).
文摘High-performance nonprecious electrocatalysts toward water splitting are in high demand but currently their development is still challenging.Here,we demonstrate that heterometallic two-dimensional(2D)metal phosphonates with improved catalytic activity and durability could be realized through defect engineering and heterometallic doping.The optimal electrocatalyst QAU-1-FeNi(1:2)exhibits prominent oxygen evolution reaction(OER)activity in alkaline electrolytes with a very low overpotential of 230 mV at 10 mA cm^(-2)and a small Tafel slope of 47 mV dec^(-1)and is superior to the commercial electrocatalyst IrO_(2).Meanwhile,QAU-1-FeNi(1:2)shows outstanding stability for at least 20 hours and continuous CV scanning for more than 2000 cycles.In this work,a novel strategy of optimization of phosphonate based electrocatalysts by defect engineering and heterometallic doping has been proposed,which has significant potential in the preparation of catalysts for energy conversion applications.
基金financially supported by the National Key Research and Development Program of China(2019YFC1904500)the National Natural Science Foundation of China(NSFC 51502036 and 21875037)+2 种基金the Department of Ecology and Environment of Fujian Province(2021R024)the Young Top Talent of Fujian Young Eagle Program of Fujian Province,the Educational Commission of Fujian Province(2022G02022)the Natural Science Foundation of Distinguished Young Scholars for Fujian Province(2019J06015).
文摘Currently,the investigation of two-dimensional(2D)crystalline materials,notably transition metal tungsten-based sulfides,is scarcely reported in the wide-temperature field.Thus,tungsten sulphide encapsulated in a sulphurized polyacrylonitrile composite(WS_(2)-SPAN)was prepared using an electrospinning technology combined with a sulphuration process.By virtue of the abundant S vacancies and in situ N doping,the WS_(2)-SPAN composite shows an impressively ultralong lifespan and stable circulation capacity over a wide temperature range(−15-50℃).For sodium storage,the WS_(2)-SPAN-2 composite delivers optimized high-rate performance and ultrastable cycling properties(464 mA h g^(-1)/450 cycles at 0.5 A g^(-1);354 mA h g^(-1)/1400 cycles at 2 A g^(-1),190 mA h g^(-1)/12000 cycles at 5 A g^(-1);129 mA h g^(-1)/18000 cycles at 10 A g^(-1),surpassing previously reported WS_(2)-based anodes for SIBs).This is paired with an Na_(3)V_(2)(PO_(4))_(3)cathode,which exhibits excellent storage capacity(241 mA h g^(-1)/200 cycles at 0.5 A g^(-1)).Potassium storage also demonstrates admirable performance(362 mA h g^(-1)/100 cycles at 0.1 A g^(-1);278 mA h g^(-1)/3000 cycles at 1 A g^(-1)).In addition,a detailed illustration of the electrochemical storage mechanism of WS_(2)-SPAN composites is presented through theoretical calculations and electrochemical dynamics.Thus,the present investigation provides new insights into the preparation of novel WS_(2)-based anodes for sodium/potassium-ion batteries with ultralong lifespans and wide-temperature workability.
