A heterostructure NiSe₂ nanoparticle @ FeSe₂ microrod catalyst for efficient electrocatalytic oxygen evolution

Finding a low-cost, efficient, and stabilized catalyst to accelerate the sluggish oxygen evolution reaction (OER) process, which hinders the production of clean hydrogen energy, is a frontier issue. Here, we synthesized a three-dimensional heterostructure NiSe₂ nanoparticle @ FeSe₂ microrod (FeSe₂/NiSe₂) electrocatalyst using a facile one-step hydrothermal method. Compared to single-phase NiSe₂ and FeSe₂ catalysts, this heterostructured catalyst exhibits an improved OER performance in alkaline electrolyte, that is, a low overpotential of 316 mV and a Tafel slope of 137 mV dec⁻¹ at a current density of 20 mA cm⁻² with a long-term durability. Benefitting from a large electrochemical active surface area provided by the specific heterostructure and the modulation of electronic structure at the heterointerface, the OER kinetics of the as-prepared FeSe₂/NiSe₂ is accelerated. This work may provide a new insight to fabricate a low-cost and efficient heterostructure electrocatalyst for oxygen evolution reaction.