Fe doped NiSe2 nanoarrays to boost electrocatalytic oxygen evolution reaction

Transition metal selenides (TMSes) have attracted increasing attention for electrocatalysts due to fascinating properties, such as low cost, intrinsic metallic properties, and high catalytic activities. In addition, bimetallic selenides exhibit more excellent performance in the oxygen evolution reaction (OER) process than monometallic selenides via synergistic effect. Herein, we synthesized Fe doped NiSe2 on carbon cloth (CC) employed as electrodes for boosting OER by a facile two-step hydrothermal method. These electrodes display excellent electrocatalytic activity for OER in alkaline electrolytes, in which Ni0.8Fe0.2Se2/CC is evidenced by the overpotential of 257 mV at the current density of 10 mA cm−2, and Tafel slope of 43 mV dec−1. The synthesized three-dimensional structure with the aid of carbon cloth helps for the mass and charge transfer. Furthermore, Fe doping not only induces stronger electron interaction but tunes electronic structure, thus improving the OER performance. After a long-term OER process, Ni0.8Fe0.2Se2 transforms into NiFe-based (oxy)hydroxides, which may serve as "real" active phase. Doping engineering strategy makes TMSes manifest a superb performance for OER and expands ways for designing effective OER electrodes.