Abstract

Abstract Hydrogen fuel is considered as one of the most clean renewable resources, warranting it a primary alternative to fossil fuels for future energy supplies. Electrocatalytic water splitting is an eco‐friendly technique for high‐purity hydrogen production. However, the sluggish dynamics of its two half‐reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), are tough challenges impeding the practical application of this technology. In these years, external field‐assisted HER and OER have attracted extensive research interests. Herein, the effects of various fields, including electric field, magnetic field, strain, and light, on electrocatalytic HER and OER are systematically discussed. The focus is how to integrate the external fields with the electrocatalytic systems and the fundamentals of field promoted HER/OER activities. In the end, the key challenges facing this rapidly progressing research field are highlighted and possible strategies addressing them are indicated.