Iron-Doped NiSe2 and Its Enhanced Oxygen Evolution Reaction Activity

Doping a third element or external functional components into binary alloy nanostructured catalysts typically significantly enhances their electrocatalytic performance. This study demonstrates that doping nickel selenide (NiSe2) with approximately 10 at% iron (Fe) is an effective strategy for improving its oxygen evolution reaction (OER) catalytic activity. The resulting Ni0.9Fe0.1Se2 undergoes a structural transformation from its original nanodendritic morphology and exhibits outstanding OER catalytic performance in alkaline media. It achieves a low overpotential of 231 mV at a current density of 10 mA cm−2, which is approximately 30% lower than that of NiSe2 (301 mV). The Tafel slope of Ni0.9Fe0.1Se2 is 116 mV dec−1. However, degradation observed after 5 h of stability testing suggests that the doping process requires further optimization.