Dynamic redistribution of intermediates induced by a local electric field microenvironment boosts efficient overall water electrolysis.

Reaction intermediates (RI) are key factors that directly determine the efficiency of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). In this study, a local electric field microenvironment was built in a FeNi and MoNi heterostructure (H-FeNiMo/NMF) to induce the redistribution of hydroxyls and protons on the metal sites during the OER and HER. H-FeNiMo/NMF requires only 270 and 155 mV to reach 100 mA cm in alkaline media for OER and HER, respectively. The catalyst exhibited satisfactory durability for 100 h at 2 A cm, with no significant attenuation in either the HER or OER. Experiments combined with computational studies demonstrated that the local electric field microenvironment can not only establish a rich OH interface during the OER but also build a rich H interface during the HER. Furthermore, the field effectively regulated the adsorption/desorption of RI during the reaction owing to the asymmetry of the charge distribution. This study offers a novel approach for the rational design of high-performance bifunctional electrocatalysts.