Self-supporting amorphous nanoporous NiFeCoP electrocatalyst for efficient overall water splitting

The design of cost-effective and earth-abundant bifunctional electrocatalysts for highly efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is important for water splitting as an advanced renewable energy transformation system. In this work, the self-supporting amorphous NiFeCoP catalyst with nanoporous structure via a facile electrochemical dealloying method is reported. Benefiting from the bicontinuous nanostructure, disordered atomic arrangement, abundant active sites and synergic effect of various transition metals, the as-prepared nanoporous NiFeCoP (np-NiFeCoP) catalyst exhibits good electrocatalytic activity, which achieves the current densities of 10 mA cm−2 at low overpotentials of 244 mV and 105 mV for OER and HER in 1.0 M KOH, respectively. In addition, the bifunctional electrocatalyst also shows outstanding and durable electrocatalytic activity in water splitting with a small voltage of 1.62 V to drive a current density of 10 mA cm−2 in a two-electrode electrolyzer system. The present work would provide a feasible strategy to explore the efficient and low-cost bifunctional electrocatalysts toward overall water splitting.