Catalysts for Efficient Alkaline Water Splitting Achieved through the Combination of Polydopamine Coordination and Nitridation Strategy

The oxygen evolution reaction (OER) is the rate‐limiting step in overall water splitting for hydrogen production. Transition metal hydroxides have emerged as the most promising candidate for efficient OER. In this study, polydopamine coordination and nitridation strategy is combined to obtain a series of bimetallic catalysts including FeCoN/NF, FeNiN/NF, FeCuN/NF, and CoCuN/NF. Competitive OER activities are achieved with the low overpotentials of 223/268 mV at the current density of 10/100 mA cm −2 in the FeCoN/NF catalyst with a good stability. The OER mechanism is further explored via the introduction of molecular probe of tetramethylammonium cation in the electrolyte and methanol oxidation reaction. The results indicate that the excellent OER activities of the catalysts are achieved through the lattice oxygen oxidation mechanism pathway. Moreover, hydrogen evolution reaction activities of the catalysts are evaluated and the low overpotentials of 302/393 mV at the current density of 10/100 mA cm −2 are achieved in the FeCoN/NF catalyst, suggesting great potential of catalysts in the overall water splitting.