We report the fabrication of highly ordered Nb_(2)O_(5)nanochannel film(Nb_(2)O_(5)-NCF)onto niobium foil by an anodization method.After thermal treatment,the obtained Nb_(2)O_(5)-NCF with rich oxygen vacancies exhibi...We report the fabrication of highly ordered Nb_(2)O_(5)nanochannel film(Nb_(2)O_(5)-NCF)onto niobium foil by an anodization method.After thermal treatment,the obtained Nb_(2)O_(5)-NCF with rich oxygen vacancies exhibits electrochemical N_(2)reduction reaction(NRR)activity with an NH3 yield rate of 2.52×10^(-10)mol cm^(-2)s^(-1)and a faradaic efficiency of 9.81%at-0.4 V(vs.RHE)in 0.1 mol/L Na2SO4 electrolyte(pH 3.2).During electrocatalytic NRR,the Nb_(2)O_(5)-NCF takes place electrochromism(EC),along with a crystalline phase transformation from pseudo hexagonal phase to hexagonal phase owing to H+insertion.This results in the reduced NRR activity due to the decrease of oxygen vacancies of hexagonal phase Nb_(2)O_(5),which can be readily regenerated by low-temperature thermal treatment or applying an anodic potential,showing superior recycling reproducibility.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2017YFA0207203)the Natural Science Foundation of China(No.51872292)。
文摘We report the fabrication of highly ordered Nb_(2)O_(5)nanochannel film(Nb_(2)O_(5)-NCF)onto niobium foil by an anodization method.After thermal treatment,the obtained Nb_(2)O_(5)-NCF with rich oxygen vacancies exhibits electrochemical N_(2)reduction reaction(NRR)activity with an NH3 yield rate of 2.52×10^(-10)mol cm^(-2)s^(-1)and a faradaic efficiency of 9.81%at-0.4 V(vs.RHE)in 0.1 mol/L Na2SO4 electrolyte(pH 3.2).During electrocatalytic NRR,the Nb_(2)O_(5)-NCF takes place electrochromism(EC),along with a crystalline phase transformation from pseudo hexagonal phase to hexagonal phase owing to H+insertion.This results in the reduced NRR activity due to the decrease of oxygen vacancies of hexagonal phase Nb_(2)O_(5),which can be readily regenerated by low-temperature thermal treatment or applying an anodic potential,showing superior recycling reproducibility.
