Cu₃P Nanoarrays Fabricated on Copper Foam Substrates Followed by Coating with CoFe Layered Double Hydroxide Nanosheets as Electrocatalysts for Water Splitting

Abstract

Developing efficient and abundant electrocatalysts for hydrogen/oxygen evolution reactions (HER/OER) is a significant challenge in the electrochemical water splitting process. This study introduces a Cu3P nanoarray structure on a copper foam substrate, intricately coated with CoFe-LDH nanosheets (Cu3P–CoFe LDH/CF). This nanoscale design significantly enhances the electrochemically active surface area, promoting water molecule adsorption and facilitating a synergistic interaction at the nanoscale heterogeneous interface between CoFe LDH and Cu3P. This interaction boosts charge transfer and improves the conductive properties of CoFe LDH, notably enhancing HER kinetics (170 ± 6 mV at a current density of 10 mA cm–2) and optimizing OER kinetics (201 ± 3 mV at a current density of 10 mA cm–2) through a synergistic oxide/hydroxide mechanism during the reaction. Cu3P–CoFe LDH/CF also demonstrates a low cell voltage of 1.60 V in overall water splitting (10 mA cm–2) and exhibits strong stability for 20 h. These observations provide valuable evidence for the practical application potential of the catalyst and highlight its usefulness.