Enabling Internal Electric Fields to Enhance Energy and Environmental Catalysis

Abstract Recent years have witnessed an upsurge of interest in exploiting advanced photo‐/electrocatalysts for efficient energy conversion and environmental remediation. Constructing internal electric fields has been highlighted as a rising star to help facilitate various catalytic processes, with the merits of promoting charge transfer/separation, optimizing redox potential and creating effective active/adsorption sites. Internal electric fields are usually formed by the polarization of uneven charge distributions between different constituent layers, which widely exist in piezoelectrics, polar surface terminations, and heterostructure materials. Herein, a groundbreaking and interdisciplinary overview of the latest advances in the construction of internal electric fields to improve photo(electro)catalytic and electrocatalytic activity is provided. This critical review begins with an encyclopedic summary of the classification, advantages, and synthesis strategies of internal electric fields. Subsequently, the identification methods are thoroughly discussed based on the characterization techniques, experiments, and theoretical calculations, which can provide profound guidance for the in‐depth study of internal electric fields. To elaborate the theory–structure–activity relationships for internal electric fields, the corresponding reaction mechanisms, modification strategies, and catalytic performance are jointly discussed, along with a discussion of their practical energy and environmental applications. Finally, an insightful analysis of the challenges and future prospects for internal electric field‐based catalysts are discussed.