YBa2Cu3-xVxO7-y(x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) superconductors have been prepared. X-ray diffraction shows that the system remains orthorhombic for all compositions studied, but for x > 0.4 V2O5 was detected...YBa2Cu3-xVxO7-y(x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) superconductors have been prepared. X-ray diffraction shows that the system remains orthorhombic for all compositions studied, but for x > 0.4 V2O5 was detected as an impurity phase. Substitution of V5+ for Cu2+ occurs in the Cu(2) sites on the Cu(2)-O planes. The introduction of the high valence element, vanadium, produces the extra free-electrons. These electrons recombine with the positive carrier of the system. It makes depression of the mobility and the Hall number of YBa2Cu3-xVxO7-v and also results in a depression of TC.展开更多
The exploration of cost-effective,high-performance,and stable electrocatalysts for the hydrogen evolution reaction(HER)over wide pH range(0–14)is of paramount importance for future renewable energy conversion technol...The exploration of cost-effective,high-performance,and stable electrocatalysts for the hydrogen evolution reaction(HER)over wide pH range(0–14)is of paramount importance for future renewable energy conversion technologies.Regulation of electronic structure through doping vanadium atoms is a feasible construction strategy to enhance catalytic activities,electron transfer capability,and stability of the HER electrode.Herein,V-doped NiCoP nanosheets on carbon fiber paper(CFP)(denoted as Vx-NiCoP/CFP)were constructed by doping V modulation on NiCoP nanosheets on CFP and used for pH-universal HER.Benefiting from the abundant catalytic sites and optimized hydrogen binding thermodynamics,the resultant V15-NiCoP/CFP demonstrates a significantly improved HER catalytic activity,requiring overpotentials of 46.5,52.4,and 85.3 mV to reach a current density of 10 mA·cm^(−2)in 1 mol·L^(−1) KOH,0.5 mol·L^(−1) H_(2)SO_(4),and 1 mol·L^(−1) phosphate buffer solution(PBS)electrolytes,respectively.This proposed cation-doping strategy provides a new inspiration to rationally enhance or design new-type nonprecious metal-based,highly efficient,and pH-universal electrocatalysts for various energy conversion systems.展开更多
基金Project supported by the National Science and Technology Committee of China and the National Natural Science Foundation of China.
文摘YBa2Cu3-xVxO7-y(x=0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) superconductors have been prepared. X-ray diffraction shows that the system remains orthorhombic for all compositions studied, but for x > 0.4 V2O5 was detected as an impurity phase. Substitution of V5+ for Cu2+ occurs in the Cu(2) sites on the Cu(2)-O planes. The introduction of the high valence element, vanadium, produces the extra free-electrons. These electrons recombine with the positive carrier of the system. It makes depression of the mobility and the Hall number of YBa2Cu3-xVxO7-v and also results in a depression of TC.
基金Key Research and Development Program of Shanxi(Grant No.201803D421085)Shanxi Scholarship Council of China(Grant No.2019070)+1 种基金Shanxi Graduate Education Innovation Project(Grant No.2020BY095)State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University(Grant No.201912)。
文摘The exploration of cost-effective,high-performance,and stable electrocatalysts for the hydrogen evolution reaction(HER)over wide pH range(0–14)is of paramount importance for future renewable energy conversion technologies.Regulation of electronic structure through doping vanadium atoms is a feasible construction strategy to enhance catalytic activities,electron transfer capability,and stability of the HER electrode.Herein,V-doped NiCoP nanosheets on carbon fiber paper(CFP)(denoted as Vx-NiCoP/CFP)were constructed by doping V modulation on NiCoP nanosheets on CFP and used for pH-universal HER.Benefiting from the abundant catalytic sites and optimized hydrogen binding thermodynamics,the resultant V15-NiCoP/CFP demonstrates a significantly improved HER catalytic activity,requiring overpotentials of 46.5,52.4,and 85.3 mV to reach a current density of 10 mA·cm^(−2)in 1 mol·L^(−1) KOH,0.5 mol·L^(−1) H_(2)SO_(4),and 1 mol·L^(−1) phosphate buffer solution(PBS)electrolytes,respectively.This proposed cation-doping strategy provides a new inspiration to rationally enhance or design new-type nonprecious metal-based,highly efficient,and pH-universal electrocatalysts for various energy conversion systems.
