Ag-Regulated Interfacial\nElectron Transfer between\nTiO<sub>2</sub> and MoS<sub><i>x</i></sub> for Enhanced\nH<sub>2</sub>O<sub>2</sub> Production

The electronic configuration mismatch between the TiO<sub>2</sub> support and the MoS<sub><i>x</i></sub> cocatalyst\ninduces\nspontaneous free-electron transfer in an unfavorable direction, resulting\nin stronger O<sub>2</sub> adsorption on Mo active sites and causing\nlimited H<sub>2</sub>O<sub>2</sub> production. Herein, we propose\na strategy for directional free-electron transfer to produce electron-enriched\nMo<sup>(4 – δ)+</sup> sites via introducing\nan Ag mediator into the TiO<sub>2</sub>/MoS<sub><i>x</i></sub> photocatalyst, which aims to weaken O<sub>2</sub> adsorption\nfor improving H<sub>2</sub>O<sub>2</sub> production activity. To achieve\nthis, a core–shell Ag@MoS<sub><i>x</i></sub> cocatalyst\nwas ingeniously constructed on the TiO<sub>2</sub> surface to synthesize\nthe TiO<sub>2</sub>/Ag@MoS<sub><i>x</i></sub> photocatalyst.\nThe resultant TiO<sub>2</sub>/Ag@MoS<sub><i>x</i></sub> achieves\na significantly enhanced H<sub>2</sub>O<sub>2</sub> production rate\nof 16.13 mmol g<sup>–1</sup> h<sup>–1</sup> with an\nAQY value of 8.79%, surpassing TiO<sub>2</sub>/Ag and TiO<sub>2</sub>/MoS<sub><i>x</i></sub> by 10.0 and 237.2 times, respectively.\nTheoretical calculations and experimental results reveal that the\nincorporation of the Ag mediator into the TiO<sub>2</sub>/Ag@MoS<sub><i>x</i></sub> system can facilitate directional free-electron\ntransfer to the MoS<sub><i>x</i></sub> cocatalyst. This\ncauses the creation of electron-enriched Mo<sup>(4 – δ)+</sup> sites and an increase in the antibonding-orbital occupancy of Mo–O<sub>ads</sub>, ultimately weakening the Mo–O<sub>ads</sub> bond\nand enabling high activity in H<sub>2</sub>O<sub>2</sub> production.\nThis study provides valuable insights into optimizing reactant adsorption\nfor efficient artificial photosynthesis.