Metal Organic Framework Derived Fe-Doped CoSe₂ Incorporated in Nitrogen-Doped Carbon Hybrid for Efficient Hydrogen Evolution

Abstract

Developing cost-efficient hydrogen evolution reaction (HER) electrocatalysts for water splitting has long been a big challenge. Here, a hybrid of Fe doped CoSe2 incorporated in nitrogen doped carbon (Fe-CoSe2@NC) was synthesized by selenization of Fe3+-etched metal organic frameworks (ZIF-67). As a result of the electronic structure engineering and morphology design, the Fe-CoSe2@NC hybrid showed an enhanced HER performance with a low overpotential of −143 mV for 10 mA cm–2 and a small Tafel slope of ∼40 mV dec–1. It also exhibited good stability and a high Faradiac efficiency. The enhanced HER activity might be owing to the increased active surface area due to Fe3+ ions etching. Moreover, the density functional theory (DFT) calculations indicate that the improved HER activity of Fe-CoSe2 could be attributed to the favorable adsorption–desorption behavior and accelerated HER kinetics, which was induced by the doping of iron atoms into CoSe2. This work comes up with a valuable strategy in designing and improving advanced electrocatalysts.