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.