Nanostructured metallic FeNi2S4 with reconstruction to generate FeNi-based oxide as a highly-efficient oxygen evolution electrocatalyst

FeNi-based nanomaterials with bimetallic alloying effect deliver a great promise as an efficient electrocatalyst for oxygen evolution reaction (OER). However, the reconstruction to generate in-situ catalytically FeNi-based oxides or hydroxides during OER process and high electrical conductivity demand foster the great pursuit of the rational design of FeNi-based OER electrocatalyst a big challenge. Herein, we design and fabricate a nanostructured metallic FeNi2S4 as a highly efficient OER electrocatalyst. This catalyst exhibits an overpotential of (250 mV) and a Tafel slope (62 mV dec−1), that outperforms the benchmark of commercial RuO2. The experimental results demonstrate that the alloying effect and the superior electrical conductivity, endow it a great electrocatalytic performance. Such a nanostructured metallic OER electrocatalyst shows a great promise in water splitting. Violarite FeNi2S4 nanostructures with tunable shapes were synthesized via a facile colloidal strategy. Benefiting from the unique nanostructure features, the synergistic effect derived from Fe, Ni, S components, and in-situ rGO supporting as well as the reconstruction in the OER process, the prepared FeNi2S4 nanoparticle (NPs) displayed excellent OER performance under alkaline electrolytes. [Display omitted] ●A colloidal method was provided to fabricate FeNi2S4 nanostructure with adjustable shape.●A high-efficiency OER electrocatalyst based on FeNi2S4 nanomaterials was reported.●The rGO support was proved to enhance the OER catalytic activity of FeNi2S4.