NiSe2 Nanoparticles Supported on Halloysite Sheets as an Efficient Electrocatalyst toward Alkaline Oxygen Evolution Reaction

Abstract

The oxygen evolution reaction (OER) with its sluggish kinetics has imposed a significant barrier to the sustainable and green generation of hydrogen fuel (via electrolysis of water) and the development of metal-air batteries. In this study, we report an efficient and novel OER electrocatalyst based on NiSe2 nanoparticles (NPs) and the naturally abundant halloysite clay mineral. The NiSe2/halloysite nanocomposite (NiSe2/H) was prepared by a simple one-step hydrothermal route. The electrocatalytic performance of the as-synthesized nanocomposite and its components (pristine NiSe2 and halloysite) toward OER in 1.0 KOH solution was examined. The NiSe2/H nanocomposite exhibited a significantly enhanced catalytic activity in OER, with a low overpotential of 235 mV (measured at the current density of 60 mA cm–2), a Tafel slope of 146 mV dec–1, and an outstanding long-term electrochemical durability for 16 h. Moreover, this nanocomposite required only 340 mV of overpotential to deliver the high current density of 250 mA cm–2. Further investigations revealed that the improved catalytic performance of NiSe2/H can be attributed to the increased number of active sites and the optimized adsorption energy of OH–. These results indicate that NiSe2/H is a promising non-precious metal-based catalyst for alkaline OER.