Enabling Internal Electric Fields to Enhance Energy and Environmental Catalysis

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.