Peony flower-like CuxS@NiMn LDH heterostructure as an efficient electrocatalyst for the oxygen evolution reaction

Hydrogen production from electrochemical water splitting has attracted more and more attention, and the development of efficient oxygen evolution reaction (OER) electrocatalyst is of great importance to this technology. In this work, peony flower-like CuxS@NiMn LDH was in situ deposited on nickel foam by simple successive ionic layer adsorption and reaction (SILAR) and hydrothermal method. The results show that CuxS exists in a mixed phase of CuS and Cu2S with porous structure, NiMn LDH grows vertically on CuxS particle surface, and a heterostructure between CuxS and NiMn LDH is formed. The CuxS@NiMn LDH/NF electrode exhibits superior OER activity with an overpotential of 263 mV at a current density of 10 mA cm−2, lower Tafel slope of only 57.79 mV dec−1, and higher stability during a 60-h test. This excellent performance is attributed to the porous structure and synergistic effect between NiMn LDH and CuxS, which can promote mass diffusion, decrease the charge transfer resistance and accelerate the electron transport during the electrocatalytic process.