Highly efficient hybrid electrocatalyst Fe4.5Ni4.5S8/Fe7S8 extracted from nickel ore for hydrogen evolution reaction

Abstract Nanoarchitecture materials are widely investigated to enhance hydrogen evolution reaction (HER) performance. However, it is beset with difficulties to obtain nanomaterials at industrial-scale in comparison with bulk materials. Herein, bulk electrocatalyst Fe4.5Ni4.5S8/Fe7S8 is prepared using flotation method and alkali cleaning from natural nickel ore. Sulfur vacancies and electron interaction between Fe7S8 and Fe4.5Ni4.5S8 may efficiently reduce hydrogen adsorption energy's absolute value, thus significantly improving hydrogen production efficiency. Hybrid catalyst requires ultralow overpotential of 48 mV at 10 mA cm-2 for HER in 0.5 M H2SO4 and exhibits high stability (maintaining an almost constant overpotential after 20,000 cyclic voltammetry sweeps). Therefore, it can be affirmed that it demonstrates promising industrial application as an electrocatalyst towards HER.