Construction of Fe3Se4@NiSe2 heterogeneous structures with low overpotentials for oxygen evolution reaction

Abstract

Hydrogen generation from electrochemical water splitting (EWS) is considered as one of the best ways to store renewable energy. To synthesize the highly effective electrocatalyst with low cost is vital to promote the larger-scale development of EWS technology. To improve the activity of NiSe2, Fe3Se4@NiSe2 heterostructures is designed and synthesized by solvothermal method and selenization treatment. Ni(OH)2 nanosheets inducing the growth of nickel iron metal-organic framework (NiFe-MOF) made up of Ni node and organic ferric ligand is designed as the precursor to gain the hierarchical morphology. The morphology, electron state and composition of Fe3Se4@NiSe2 are engineered through adjusting the condition of selenidation treatment. Benefiting from the tuned electron state of Ni, Se elements, hierarchical morphology and lower Rct value, the optimized Fe3Se4@NiSe2 electrode exhibits ultralow overpotentials (110 mV) for oxygen evolution reaction (OER) to drive 10 mA cm−2, small Tafel slope (29.32 mV dec−1) and high Faraday efficiency (FE = 99.50 %) in 1 M KOH. The construction of Fe3Se4@NiSe2 provide novel electrocatalyst as an outstanding non-precious electrocatalysts for OER.