Modularization of Regional Electronic Structure over Defect-Rich CeO₂ Rods for Enhancing Photogenerated Charge Transfer and CO₂ Activation

Oxygen vacancy (OV) engineering has been widely applied in different types of metal oxide-based photocatalytic reactions. Our study has shown that the redistributed OVs resulting from voids in CeO₂ rods lead to significant differences in the band structure in space. The flat energy band within the highly crystallized bulk region hinders the recombination of photogenerated carrier pairs during the transfer process. The downward curved energy band in the surface region enhances the activation of the absorbents. Therefore, the localization of the band structure through crystal structure regionalization renders V-CeO₂ capable of achieving efficient utilization of photogenerated carriers. Practically, the V-CeO₂ rod shows a remarkable turnover number of 190.58 μmol g^–1 h^–1 in CO₂ photoreduction, which is ∼9.4 times higher than that of D-CeO₂ (20.46 μmol g^–1 h^–1). The designed modularization structure in our work is expected to provide important inspiration and guidance in coordinating the kinetic behavior of carriers in OV defect-rich photocatalysts.