Interfacial construction of P25/Bi2WO6 composites for selective CO2 photoreduction to CO in gas–solid reactions

Abstract

Photocatalysis provides an attractive approach to convert CO₂ into valuable fuels, which relies on a well-designed photocatalyst with good selectivity and high CO₂ reduction ability. Herein, a series of P25/Bi₂WO₆ nanocomposites were synthesized by a simple one-step in situ hydrothermal method. The formation of a heterojunction between Bi₂WO₆, which absorbs visible light, and P25, which absorbs ultraviolet light, expands the utilization of sunlight by the catalysts, and consequently, leads to a remarkably enhanced CO₂ selective photoreduction to CO. The maximum CO yield of the P25/Bi₂WO₆ heterojunction under simulated solar irradiation was 15.815 μmol g⁻¹ h⁻¹, which was 4.04 and 2.80 times higher than that of pure P25 and Bi₂WO₆, respectively. Our investigations verified a Z-scheme charge migration mechanism based on various characterization techniques between P25 and Bi₂WO₆. Furthermore, in situ DRIFTS uncovered the related reaction intermediates and CO₂ photoreduction mechanism. Our work sheds light on investigating the efficacious construction of Bi₂WO₆-based hybrids for light-driven photocatalysis.