Synergistic Coupling of CoFe-LDH Nanosheets with Cu₃P Nanoarrays for Efficient Water Splitting

A crucial requirement for overall water splitting (OWS) is the creation of highly active bifunctional electrocatalysts. In this study, a CoFe-LDH (LDH = layered double hydroxide) nanosheet is integrated on a Cu₃P nanowire to form heterogeneous structure Cu₃P@CoFe-LDH/CF. Studies prove that the formation of a p–n heterojunction between Cu₃P and CoFe-LDH promotes the charge-transfer reaction. Due to the synergistic contribution of the heterogeneous structure, Cu₃P@CoFe-LDH/CF displays promising electrocatalytic activity. The overpotentials of 293 mV at 100 mA cm^–2 for oxygen evolution reaction and 181 mV at 100 mA cm^–2 for hydrogen evolution reaction are achieved in 1 M KOH. In addition, the alkaline electrolyzer of Cu₃P@CoFe-LDH/CF||Cu₃P@CoFe-LDH/CF shows a low cell voltage of 1.45 V at 10 mA cm^–2 as well as great stability for OWS. This work provides a facile method to enhance the electrocatalytic activity by constructing heterogeneous structures with p–n heterojunctions, which holds significant promise for application in renewable energy technology.