Development of cheap,abundant and noblemetal-free materials as high efficient oxygen reduction electrocatalysts is crucial for future energy storage system. Here,one-dimensional（1D） MnO N-doped carbon nanofibers（Mn...Development of cheap,abundant and noblemetal-free materials as high efficient oxygen reduction electrocatalysts is crucial for future energy storage system. Here,one-dimensional（1D） MnO N-doped carbon nanofibers（MnO-NCNFs） were successfully developed by electrospinning combined with high temperature pyrolysis. The MnO-NCNFs exhibit promising electrochemical performance,methanol tolerance,and durability in alkaline medium. The outstanding electrocatalytic activity is mainly attributed to several issues.First of all,the uniform 1D fiber structure and the conductive network could facilitate the electron transport. Besides,the introduction of Mn into the precursor can catalyze the transformation of amorphous carbon to graphite carbon,while the improved graphitization means better conductivity,beneficial for the enhancement of catalytic activity for oxygen reduction reaction（ORR）. Furthermore,the porous structure and high surface area can effectively decrease the mass transport resistance and increase the exposed ORR active sites,thus improve utilization efficiency and raise the quantity of exposed ORR active sites. The synergistic effect of MnO and NCNFs matrix,which enhances charge transfer,adsorbent transport,and delivers efficiency in the electrolyte solution,ensures the high ORR performance of MnO-NCNFs.展开更多
It is a great challenge to prepare non-noble metal electrocatalysts toward hydrogen evolution reaction(HER)with large current density.Synergistic electronic and morphological structures of the catalyst have been consi...It is a great challenge to prepare non-noble metal electrocatalysts toward hydrogen evolution reaction(HER)with large current density.Synergistic electronic and morphological structures of the catalyst have been considered as an effective method to improve the catalytic performance,due to the enhanced intrinsic activity and enlarged accessible active sites.Herein,we present novel ternary Co_(1-x)V_(x)P nanoneedle arrays with modulated electronic and morphological structures as an electrocatalyst for highly efficient HER in alkaline solution.The NF@Co1-xVxP catalyst shows a remarkable catalytic ability with low overpotentials of 46 and 226 mV at current densities of 10 and 400 mA cm^(-2),respectively,as well as a small Tafel slope and superior stability.Combining the experimental and computational study,the excellent catalytic performance was attributed to the improved physical and chemical properties(conductivity and surface activity),large active surface area,and fast reaction kinetics.Furthermore,the assembled Co–V based electrolyzer(NF@Co_(1-x)V_(x)–HNNs(+)||NF@Co_(1-x)V_(x)P(-))delivers small full-cell voltages of 1.58,1.75,and 1.92 V at 10,100,and 300 mA cm^(-2),respectively.Our findings provide a systematic understanding on the V–incorporation strategy to promote highly efficient ternary electrocatalysts via synergistic control of morphology and electronic structures.展开更多
Germanium based sulfides are potentially attractive as anode material for sodium ion batteries but rarely investigated. Herein, we firstly investigated Na^＋storage properties of pristine Cu2GeS3（PCGS） and found an ...Germanium based sulfides are potentially attractive as anode material for sodium ion batteries but rarely investigated. Herein, we firstly investigated Na^＋storage properties of pristine Cu2GeS3（PCGS） and found an effective strategy to improve its performance by a single lithiation/delithiation cycle obtaining ultrafine nanoparticle copper germanium sulfide（NCGS）. The lithiation/delithiation process leads to the formation of a stable Li-containing solid electrolyte interphase film and a significant improvement of sodiation kinetics. Therefore, the NCGS anode delivers favorable capacity retention and better rate capability compared with that of a PCGS whether in the half cell or in the full cell,showing great promise for energy storage application.展开更多
基金supported by the National Natural Science Foundation of China (21671096 and 21603094)the Natural Science Foundation of Guangdong Province (2016A030310376)+2 种基金Shenzhen Key Laboratory Project (ZDSYS201603311013489)the Natural Science Foundation of Shenzhen (JCYJ20150630145302231 and JCYJ20150331101823677)the Undergraduate Training Program for Innovation and Entrepreneurship of Guangdong (2016S10)
文摘Development of cheap,abundant and noblemetal-free materials as high efficient oxygen reduction electrocatalysts is crucial for future energy storage system. Here,one-dimensional（1D） MnO N-doped carbon nanofibers（MnO-NCNFs） were successfully developed by electrospinning combined with high temperature pyrolysis. The MnO-NCNFs exhibit promising electrochemical performance,methanol tolerance,and durability in alkaline medium. The outstanding electrocatalytic activity is mainly attributed to several issues.First of all,the uniform 1D fiber structure and the conductive network could facilitate the electron transport. Besides,the introduction of Mn into the precursor can catalyze the transformation of amorphous carbon to graphite carbon,while the improved graphitization means better conductivity,beneficial for the enhancement of catalytic activity for oxygen reduction reaction（ORR）. Furthermore,the porous structure and high surface area can effectively decrease the mass transport resistance and increase the exposed ORR active sites,thus improve utilization efficiency and raise the quantity of exposed ORR active sites. The synergistic effect of MnO and NCNFs matrix,which enhances charge transfer,adsorbent transport,and delivers efficiency in the electrolyte solution,ensures the high ORR performance of MnO-NCNFs.
基金the National Natural Science Foundation of China(21671096,21603094 and21905180)the Natural Science Foundation of Guangdong Province(2018B030322001 and 2018A030310225)+4 种基金Shenzhen Peacock Plan(KQTD2016022620054656)Shenzhen Key Laboratory Project(ZDSYS201603311013489)the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen(JCYJ20190809115413414)the Science and Technology Development Fund from Macao SAR(FDCT–0102/2019/A2,FDCT–0035/2019/AGJ and FDCT–0154/2019/A3)the Multi-Year Research Grants(MYRG2017–00027–FST and MYRG2018–00003–IAPME)from the University of Macao。
文摘It is a great challenge to prepare non-noble metal electrocatalysts toward hydrogen evolution reaction(HER)with large current density.Synergistic electronic and morphological structures of the catalyst have been considered as an effective method to improve the catalytic performance,due to the enhanced intrinsic activity and enlarged accessible active sites.Herein,we present novel ternary Co_(1-x)V_(x)P nanoneedle arrays with modulated electronic and morphological structures as an electrocatalyst for highly efficient HER in alkaline solution.The NF@Co1-xVxP catalyst shows a remarkable catalytic ability with low overpotentials of 46 and 226 mV at current densities of 10 and 400 mA cm^(-2),respectively,as well as a small Tafel slope and superior stability.Combining the experimental and computational study,the excellent catalytic performance was attributed to the improved physical and chemical properties(conductivity and surface activity),large active surface area,and fast reaction kinetics.Furthermore,the assembled Co–V based electrolyzer(NF@Co_(1-x)V_(x)–HNNs(+)||NF@Co_(1-x)V_(x)P(-))delivers small full-cell voltages of 1.58,1.75,and 1.92 V at 10,100,and 300 mA cm^(-2),respectively.Our findings provide a systematic understanding on the V–incorporation strategy to promote highly efficient ternary electrocatalysts via synergistic control of morphology and electronic structures.
基金National Natural Science Foundation of China (51502319)Shandong Provincial Natural Science Foundation (BS2015CL014)the Think-Tank Mutual Fund of Qingdao Energy Storage Industry Scientific Research and Qingdao Key Lab of Solar Energy Utilization and Energy Storage Technology
文摘Germanium based sulfides are potentially attractive as anode material for sodium ion batteries but rarely investigated. Herein, we firstly investigated Na^＋storage properties of pristine Cu2GeS3（PCGS） and found an effective strategy to improve its performance by a single lithiation/delithiation cycle obtaining ultrafine nanoparticle copper germanium sulfide（NCGS）. The lithiation/delithiation process leads to the formation of a stable Li-containing solid electrolyte interphase film and a significant improvement of sodiation kinetics. Therefore, the NCGS anode delivers favorable capacity retention and better rate capability compared with that of a PCGS whether in the half cell or in the full cell,showing great promise for energy storage application.
