Tailoring π-symmetry electrons in cobalt–iron phosphide for highly efficient oxygen evolution

Developing highly efficient and affordable catalysts towards oxygen evolution reaction (OER) is highly desirable, but still faces challenges. Here, we report a novel Fe doped CoP nanocuboid (Co x Fe 1-x P) via the successive oxidation and phosphidation of the Co–Fe precursor strategy. By preparation and measurement of the control samples, the optimized Co 0.8 Fe 0.2 P is found, affording an overpotential of 285 mV to deliver a current density of 10 mA cm −2 , yielding a Tafel slope of 40 mV dec −1 , and endowing robust stability for 10 h with only 5.78% degradation. The outstanding OER performance should be ascribed to the redistribution of the electron spin status via π-donation due to the introduction of Fe into the CoP lattices, enabling optimization of the adsorption/desorption feature of the intermediate species on the catalyst surface. This work paves the ways for exploration of high efficient catalysts with deliberate electron spin tailoring.