Synergy of Bulk Defects and Surface Defects on TiO₂ for Highly Efficient Photocatalytic Production of H₂O₂

Abstract

Artificial photosynthesis of H₂O₂ by TiO₂-based semiconductors is a promising approach for H₂O₂ production. However, the efficiency of pristine TiO₂ is still limited by rapid charge separation and low O₂ adsorption capacity. Here, we found that the synergy between bulk and surface defects on TiO₂ could overcome this demanding bottleneck. The introduced bulk defects act as hole acceptors to induce directional hole transfer, efficiently boosting electron-hole separation. Furthermore, the adsorption of O₂ is strengthened by the introduced surface defects. Consequently, this synergy of bulk and surface defects on TiO₂ significantly improves the photocatalytic performance, with a H₂O₂ production rate of 4560 μmol h^-1 g^-1, outperforming most reported TiO₂-based photocatalysts. This work not only provides a new insight into the mechanism of surface/bulk defects in photocatalysis but also highlights that surface/bulk regulation holds great promise for achiveing efficient photocatalytic conversion.