An S-scheme CdS/K2Ta2O6 heterojunction photocatalyst for production of H2O2 from water and air.

[Display omitted] • A flower-like CdS/K 2 Ta 2 O 6 S-scheme heterojunction was prepared. • The S-scheme charge transfer mechanism between CdS and K 2 Ta 2 O 6 was revealed. • Excellent ability for photocatalytic H 2 O 2 production from water and air. • The route and mechanism of the photocatalytic H 2 O 2 production were proposed. The hydrogen peroxide (H 2 O 2) production using solar energy is of great significance in chemical industry and environmental remediation. However, this technique requires that photocatalysts have efficient charge separation and migration efficiency. Herein, we designed a flower-like CdS/K 2 Ta 2 O 6 (CdS/KTO) S-scheme heterojunction with promoted charge separation and migration by a facile two-step hydrothermal strategy. The CdS/KTO photocatalyst exhibited an outstanding performance with a H 2 O 2 production rate of 160.89 μmol g−1 h−1 without using any sacrificial agents and adding additional O 2. The combination of the in situ irradiated X-ray photoemission spectroscopy (XPS), electron paramagnetic resonance (EPR) and density functional theory (DFT) calculations revealed that the formation of an S-scheme heterojunction between CdS and KTO could greatly promote the separation of photogenerated electron-hole pairs toward efficient H 2 O 2 production. This work provides insights for the charge transfer mechanism of S-scheme heterojunction and an innovative stratagem for green, energy-saving and sustainable H 2 O 2 production. [ABSTRACT FROM AUTHOR]