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.