Internal Electric Field and Adsorption Effect Synergistically Boost Carbon Dioxide Conversion on Cadmium Sulfide@Covalent Triazine Frameworks Core–Shell Photocatalyst

Abstract Solar‐driven photocatalytic conversion of carbon dioxide (CO₂) into carbon‐neutral fuels is of significance for energy sustainability. The critical challenges in this process are high charge carrier recombination and low CO₂ adsorption capacity. Here, by integrating porous covalent triazine frameworks (CTFs) with cadmium sulfide (CdS) nanospheres, a CdS@CTF‐HUST‐1 heterojunction photocatalyst with core–shell structure is developed for CO₂‐to‐CO conversion. Experimental investigations combined with density functional theory simulations reveal that the formation of an internal electric field provides the driving force for accelerating S‐scheme charge transfer, resulting in enhanced separation and utilization efficiency of charge carriers in photocatalysis. Together with the improved CO₂ adsorption capacity contributed by the porous structure of the CTF‐HUST‐1 shell, the CdS@CTF‐HUST‐1 heterojunction photocatalyst gives an impressive CO yield rate of 168.77 µmol g⁻¹ h⁻¹ with high selectivity. This research furnishes a feasible strategy to construct highly active core–shell composite photocatalysts for optimizing CO₂ adsorption and conversion.