Efficient MMoO4 (M = Co, Ni) carbon cloth electrodes for water oxidation

Abstract

The development of stable, highly active and cheap electrocatalysts towards the oxygen evolution reaction (OER) has been an ongoing challenge due to practical problems such as slow kinetics and high overpotential. Herein, we utilized a one-pot hydrothermal method to prepare cobalt/nickel molybdate hierarchical microflowers on conductive carbon cloth (MMoO₄-CC, M = Co, Ni) as three-dimensional self-supported electrodes for the oxygen evolution reaction. CoMoO₄-CC showed better catalytic activity than NiMoO₄-CC. Benefiting from the synergistic effect of a large active area, fast charge and mass transport as well as a three-dimensional conducting path, the CoMoO₄-CC nanosheet electrode showed a large current density and a relatively low starting potential, delivering 10 mA cm⁻² current densities at an overpotential of 290 mV and a Tafel slope of 94 mV dec⁻¹. Furthermore, the CoMoO₄-CC nanomaterial shows better electrocatalytic stability than IrO₂-CC^a, which could be a promising electrocatalyst for large-scale water oxidation.