In order to solve the contradiction between the rapidly growing energy demand and the excessive exploitation of fossil fuels,it is urgent to research and develops more environmentally friendly and efficient energy sto...In order to solve the contradiction between the rapidly growing energy demand and the excessive exploitation of fossil fuels,it is urgent to research and develops more environmentally friendly and efficient energy storage technologies.Therefore,the development of high-performance cathode materials to enhance the energy density of SIB is currently one of the most important topics of scientific research.Advanced high-voltage and low-cost cathode material for SIBs,a composite of carbon-coated Na_(4)MnCr(PO_(4))_(3)(NASICON-type),polyvinylpyrrolidone(PVP),and modified carbon nanotubes(CNTs)is prepared by sol-gel and freeze-drying method.Due to the high conductivity of CNTs,the conductivity of the composite is significantly improved,and its initial capacity is increased to 114 mAh/g at 0.5 C and 96 mAh/g at 5 C(Mn^(2+)/Mn^(4+)conversion for voltage windows 1.4-4.3 V).Moreover,the multi-electrons transfer of Cr^(3+)/Cr^(4+) and Mn^(2+)/Mn^(4+) can provide a high capacity of 165 mAh/g at 0.1 C and 102 mAh/g at 5 C in the high voltage window of 1.4-4.6 V.Furthermore,PVP can effectively inhibit the Jahn-Teller effect caused by Mn ion,making the composite have more excellent high-rate performance and stability.In addition,GITT,EIS and CV curves were drawn to better reveal the excellent kinetic properties of Na_(4)MnCr(PO_(4))_(3)@C@PVP@CNT cathode,and the mechanism of its performance improvement is deeply studied and discussed.Accordingly,the co-doping of CNTs and PVP is a simple way to high conductivity and fast charging of cathode materials for SIBs.展开更多
Solar-to-hydrogen conversion through photocatalysis is a sustainable and promising strategy for storing solar energy.Recently,elemental red phosphorus(RP)with broad light absorption has been recognized as a potential ...Solar-to-hydrogen conversion through photocatalysis is a sustainable and promising strategy for storing solar energy.Recently,elemental red phosphorus(RP)with broad light absorption has been recognized as a potential candidate for photocatalytic hydrogen evolution,while challenges remain due to the rapid recombination of photogenerated carriers.In this work,RP modified TiO_(2)hollow spheres were designed and fabricated through the chemical vapor deposition method.The optimal hydrogen production rate reaching 215.5μmol/(g h)over TiO_(2)@RP heterostructure was obtained under simulated solar light irradiation.Experimental results evidenced that the hollow sphere structure and RP light absorber extended light absorption ability,and the heterostructure induced interfacial charge migration facilitated photoinduced charge separation,which benefited the photocatalytic hydrogen production performance.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21571080,62174152 and 12204219).
文摘In order to solve the contradiction between the rapidly growing energy demand and the excessive exploitation of fossil fuels,it is urgent to research and develops more environmentally friendly and efficient energy storage technologies.Therefore,the development of high-performance cathode materials to enhance the energy density of SIB is currently one of the most important topics of scientific research.Advanced high-voltage and low-cost cathode material for SIBs,a composite of carbon-coated Na_(4)MnCr(PO_(4))_(3)(NASICON-type),polyvinylpyrrolidone(PVP),and modified carbon nanotubes(CNTs)is prepared by sol-gel and freeze-drying method.Due to the high conductivity of CNTs,the conductivity of the composite is significantly improved,and its initial capacity is increased to 114 mAh/g at 0.5 C and 96 mAh/g at 5 C(Mn^(2+)/Mn^(4+)conversion for voltage windows 1.4-4.3 V).Moreover,the multi-electrons transfer of Cr^(3+)/Cr^(4+) and Mn^(2+)/Mn^(4+) can provide a high capacity of 165 mAh/g at 0.1 C and 102 mAh/g at 5 C in the high voltage window of 1.4-4.6 V.Furthermore,PVP can effectively inhibit the Jahn-Teller effect caused by Mn ion,making the composite have more excellent high-rate performance and stability.In addition,GITT,EIS and CV curves were drawn to better reveal the excellent kinetic properties of Na_(4)MnCr(PO_(4))_(3)@C@PVP@CNT cathode,and the mechanism of its performance improvement is deeply studied and discussed.Accordingly,the co-doping of CNTs and PVP is a simple way to high conductivity and fast charging of cathode materials for SIBs.
基金financially supported by the National Natural Science Foundation of China(Nos.51672143,51808303,52102362)Taishan Scholar Program of Shandong Province,Outstanding Youth of Natural Science in Shandong Province(No.JQ201713)+2 种基金Applied Basic Research of Qingdao City(Special Youth Project)(No.19-6-2-74-cg)State Key Laboratory of Bio-Fibers and Eco-Textiles(Qingdao University)(Nos.ZKT-25,ZKT-26,and ZKT-30)Science and Technology Support Plan for Youth Innovation of Colleges in Shandong Province(No.DC2000000961)。
文摘Solar-to-hydrogen conversion through photocatalysis is a sustainable and promising strategy for storing solar energy.Recently,elemental red phosphorus(RP)with broad light absorption has been recognized as a potential candidate for photocatalytic hydrogen evolution,while challenges remain due to the rapid recombination of photogenerated carriers.In this work,RP modified TiO_(2)hollow spheres were designed and fabricated through the chemical vapor deposition method.The optimal hydrogen production rate reaching 215.5μmol/(g h)over TiO_(2)@RP heterostructure was obtained under simulated solar light irradiation.Experimental results evidenced that the hollow sphere structure and RP light absorber extended light absorption ability,and the heterostructure induced interfacial charge migration facilitated photoinduced charge separation,which benefited the photocatalytic hydrogen production performance.
