Hollow core–shell heterojunction TAPB-COF@ZnIn₂S₄ as highly efficient photocatalysts for carbon dioxide reduction

The conversion of carbon dioxide (CO₂) into carbon-neutral fuels using solar energy is crucial for achieving energy sustainability. However, the high carrier charge recombination and low CO₂ adsorption capacity of the photocatalysts present significant challenges. In this paper, a TAPB-COF@ZnIn₂S₄-30 (TAPB-COFZ-30) heterojunction photocatalyst was constructed by <i>in situ</i> growth of ZnIn₂S₄ (ZIS) on a hollow covalent organic framework (HCOF) with a hollow core-shell structure for CO₂ to CO conversion. Both experimental studies and theoretical calculations indicate that the construction of heterojunctions improves the efficiency of carrier separation and utilisation in photocatalysis. The yield of photoreduction of CO₂ to CO by the TAPB-COFZ-30 heterojunction photocatalyst reached 2895.94 μmol g^-1 with high selectivity (95.75%). This study provides a feasible strategy for constructing highly active core-shell composite photocatalysts to optimize CO₂ reduction.