Enhancing oxygen evolution reaction of CoP nanosheets via interfacial engineering with CoFe-LDH nanosheets

Abstract

Recently, transition-metal phosphides have emerged as favorable electrocatalysts for facilitating oxygen evolution reactions (OERs). This study successfully synthesized a heterostructure comprising interconnected ultrathin nanosheet arrays of CoxP grown on nickel foam (NF) through electrodeposition and phosphorization processes. Subsequently, a layer of CoFe layered double hydroxides (LDH) was electrodeposited onto the CoxP/NF substrate, resulting in the formation of the heterostructure CoxP@CoFe-LDH. The OER efficiency of the CoxP nanosheets exhibited substantial improvement because of the more accessible active sites and faster electron transfer capability of the heterostructure system. This improvement can be attributed to the higher surface area and well-established interfacial coupling between the ultrathin nanosheets of CoxP and CoFe-LDH. Consequently, the CoxP6@CoFe2/NF anode displays remarkable performance in enabling OERs, requiring merely a minimal overpotential of 230 mV at a current density of 10 mA·cm−2 in 1 M KOH. This result signifies a substantial improvement when compared to the performance of the bare CoxP and CoFe-LDH samples. Moreover, the heterostructure system enhanced the structural durability during the OERs, leading to remarkable stability over a continuous operation period of 50 h.