A hollow CuS–CuO nanocube core and NiFe-LDH nanosheet shell electrocatalyst for enhanced oxygen evolution reaction

Abstract

Developing highly efficient and durable non-noble metal electrocatalysts for the oxygen evolution reaction (OER) remains a significant challenge. Herein, we synthesized a core–shell electrocatalyst, which consists of a hollow CuS–CuO nanocube core coated with a NiFe-LDH nanosheet shell (CuS–CuO@NiFe-LDH). Compared with the mono-structured electrocatalyst, the hybrid electrocatalyst, a CuS–CuO core coupled with a NiFe-LDH shell, offers a significantly larger specific surface area and a richer variety of pores. This architecture ensures more accessible active sites and provides abundant channels for ionic, electrolyte and product transport. Moreover, the strong interfacial interaction between CuS–CuO and NiFe-LDH promotes the electron rearrangement, promoting the formation of oxidation intermediates to facilitate the activity and dynamics of the OER. Electrochemical tests show that the optimized CuS–CuO@NiFe-LDH exhibits a low overpotential of 285 mV at 10 mA cm⁻², a Tafel slope of 47.65 mV dec⁻¹, and stable performance for up to 15 h under alkaline conditions. This work provides valuable insights into the design of core–shell structured anode catalysts for efficient OER.