Facile electrosynthesis of Fe (Ni/Co) hydroxyphosphate as a bifunctional electrocatalyst for efficient water splitting

Porous iron–nickel hydroxyphosphate and iron–cobalt hydroxyphosphate electrodes are prepared by one-step electrodeposition method. The as-prepared iron–nickel hydroxyphosphate and iron–cobalt hydroxyphosphate electrodes show excellent performance for water splitting with high catalytic activity towards the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), with a lower overpotential of 220 and 235 mV for the OER and 145 and 160 mV for the HER, respectively. Moreover, two-electrode electrolyzer using iron-nickel hydroxyphosphate as both the anode and cathode requires a cell voltage of 1.65 V while iron–cobalt hydroxyphosphate requires cell voltage of 1.67 V to gain current density of 10 mA cm−2.