Enhancing Photocatalytic H ₂ O ₂ Production Over Ag Co‐Catalyst Through Charge Transfer Modulation

ABSTRACT Recently, noble metal nanoparticles (e.g., Au, Ag, and Pt) have gained widespread attention as promising co‐catalysts with potential applications in reducing O ₂ into H ₂ O ₂ . However, the O ₂ ‐to‐H ₂ O ₂ conversion efficiency is generally limited due to their inherent weak adsorption capability toward O ₂ . Herein, we have designed p‐type Ag/CdZnS Schottky junctions to address this issue. It is demonstrated that Ag nanoparticles are regulated to be electron‐deficient through diffusion of thermoelectrons (thermally excited at any temperature) from Ag to CdZnS, thereby enhancing O ₂ adsorption on the Ag active sites. On the other hand, the photoelectrons generated in CdZnS during the photocatalysis process are driven by the created interface electric field to reach the Ag active sites for photoreduction reactions. The yield rate of H ₂ O ₂ over the optimal photocatalyst 0.7Ag/CZS reaches 1450 µmol g ⁻¹ h ⁻¹ , showing a 3.1 fold increase over that of single CdZnS. Density functional theory (DFT) calculations and experimental characterizations were combined to elucidate the charge transfer, O ₂ adsorption, and photocatalysis mechanisms. The present work highlights an important strategy to optimize the noble metal co‐catalysts for achieving excellent photocatalytic H ₂ O ₂ synthesis.