Fe-V@NiO heterostructure electrocatalyst towards oxygen evolution reaction
The development of nonprecious and earth-abundant electrocatalyst with high electrocatalytic activity for oxygen evolution reaction (OER) is a rising hot issue and remains a grand challenge. In the present work, we proposed a facile strategy to construct ultrathin NiO nanosheet decorated with Fe-V nanoparticles on nickel foam (Fe-V@NiO/NF) used as OER electrocatalyst. Due to the 3D rational configuration, the Fe-V@NiO/NF with heterostructure shows excellent electrocatalytic activity towards OER. Interestingly, it is found that in situ oxidation by galvanostatic electrolysis in alkaline solution benefits to enhance the OER performance. After 10 h electrolysis, a current density of 50 mA cm-2 will achieve at a low overpotential of 271.1 mV. This is because that during the in situ oxidation process, iron and vanadium ions insert into the NiO lattice and lead to the generation of high active α-FeOOH and amorphous (oxy)-hydroxides layer. Additionally, the charge transfer resistance dramatically reduces with the prolonging of oxidation time.