Precisely loading Pt on Tb4O7/CN heterojunction for efficient photocatalytic overall water splitting: Design and mechanism

Constructing heterojunction is an effective strategy for fighting electron-hole pairs recombination. Loading of hydrogen evolution reaction (HER) cocatalysts on a heterojunction is crucial for efficient photocatalytic overall water splitting (POWS). However, how to achieve a synergy between the heterojunction and HER cocatalyst remains a challenge. Herein, we propose a novel design strategy: selectively loading HER cocatalyst Pt on Tb4O7/CN. We found that engineering Pt on the Tb4O7 section of Tb4O7/CN can synergistically promote the photogenerated charge separation and thus enhances the POWS activity. The H2 production rate is about 2.8 times higher than that of Tb4O7/CN. In contrast, engineering Pt on the CN section leads to increasing photogenerated electron-hole recombination and deactivating the POWS activity, about 2.6 times as low as that of Tb4O7/CN. These findings highlight the significance of synergism of Pt loading sites with the charge separation of heterojunctions, providing insights on developing efficient photocatalysts for POWS.