Photocatalytic H2O splitting and CO2 reduction with internal electric field modulation

The separation efficiency of the photogenerated carriers was regarded as one of the most critical factors in photocatalytic renewable fuel production from H2O splitting and CO2 reduction. The charge separation efficiency was considered as one of the main reasons. Recently, studies on the built-in electric field in photocatalysis received much attention and were proposed as the most important factors for the improvement of photocatalytic efficiency since it will affect the separation efficiency of photocarriers during the procedure phase migration. In this review, the research related to the built-in electric field modulation was investigated and summarized. The fundamental formation mechanisms and the measurement technique of the internal electric field were concluded. More importantly, several strategies, like element doping (including the coordination bond construction method, unit cell distortion and structure modulation, surface gradient diffusion, the anion exchange, and single atom exchange) and defects engineering, junction engineering (including p-n junction, heterojunction, facet junction as well as hetero-homojunction), functional group modulation (for organic photocatalysts), were proposed as the significant method for the modulation of internal electric field, which also has the potential to be an efficient strategy for promoting the generation rate and selectively of renewable fuels via photocatalysis.