Benzoate Anion‐Intercalated Layered Cobalt Hydroxide Nanoarray: An Efficient Electrocatalyst for the Oxygen Evolution Reaction

Efficient oxygen evolution reaction (OER) catalysts are highly desired to improve the overall efficiency of electrochemical water splitting. We develop a benzoate anion-intercalated layered cobalt hydroxide nanobelt array on nickel foam (benzoate-Co(OH)₂ /NF) through a one-pot hydrothermal process. As a 3 D electrode, benzoate-Co(OH)₂ /NF with an expanded interlayer spacing (14.72 Å) drives a high OER catalytic current density of 50 mA cm^-2 at an overpotential of 291 mV, outperforming its carbonate anion-intercalated counterpart with a lower interlayer spacing of 8.81 Å (337 mV overpotential at 50 mA cm^-2 ). Moreover, this benzoate-Co(OH)₂ /NF can maintain its catalytic activity for 21 h.