In-situ hydrothermal roasting of Ni-based oxide as efficient oxygen evolution reaction catalysts

Abstract

Oxygen evolution reaction (OER) is the key reaction in the water splitting and CO2 electrochemical reduction. However, the current catalysts for OER still suffer from high potentials and poor stability. Herein, hierarchical self-supporting Ni-based oxides (NiMOx)/Ni–V/Ni foam (NF) (M = Fe, Co, Cu, Mo) catalysts are directly grown on NF by in-situ hydrothermal roasting method. The OER activity of a series of Ni-based oxide catalysts doped with different metal are investigated. The results demonstrate that the NiFeOx/Ni–V/NF exhibits the best OER activity. At the current density of 10 mA cm−2, a smaller overpotential for OER of 270 mV is achieved in 1.0 M KOH electrolyte. No obvious decay in performances is observed after constant electrolysis of about 25 h, demonstrating its outstanding stability. The formation of new oxides compounds and the structure changes due to the addition of Fe, Co, Cu, Mo to the NiOx contribute to the improvements in activity.