Selenium-induced NiSe2@CuSe2 hierarchical heterostructure for efficient oxygen evolution reaction

Electrochemical water splitting is widely studied in the hope of solving the environmental deterioration and energy shortage. The design of inexpensive metal catalysts showing desired catalytic performance and durable stability for efficient oxygen evolution is the pursuit in sustainable and clean energy fields. Herein, a three-dimensional (3D) flower-like NiSe2 primary structure, modified with highly dispersed CuSe2 nanoclusters as secondary structure, is obtained by regulating the growth trend of the nanosheets. Benefiting from the metallicity of selenides and the formation of heterogeneous interface, NiSe2@CuSe2/NF shows comparable performance toward the oxygen evolution reaction (OER) in an alkaline environment. By regulating the synthesis conditions, it is exploited that the catalyst exhibits the optimal performance with ultralow overpotential for the OER when the Ni/Cu molar ratio is 1:0.2, and the hydrothermal temperature and the hydrothermal time are 200 °C and 6 h, respectively. It provides a current density of 10 mA cm-2 when the potential of 201 mV is applied without iR compensation. In this work, the hierarchical heterostructure of NiSe2 and CuSe2 is synthesized, which performs high electroacatalytic activity to oxygen evolution, and provides a new possibility for the extensive application of copper-based compounds in advanced energy fields.