Tailoring reactant adsorption on WO₃ via surface bismuth incorporation for enhanced photocatalytic degradation of acetaldehyde

The reactive oxygen species (ROS) are of paramount importance for indoor volatile organic compounds removal through photocatalytic technology. However, generating abundant ROS under visible light remains challenging, resulting in the poor photocatalytic performance. Herein, we report a bismuth-modified tungsten oxide (WO₃-Bi) photocatalyst with enhanced performance in the visible-light-driven degradation of acetaldehyde, a major indoor air pollutant. Bismuth atoms are atomically doped onto WO₃ surface, in which the strong Bi-O adsorption strength facilitates the water and oxygen adsorption to provide abundant ROS. Mechanistic investigations reveal that the photocatalytic oxidation of acetaldehyde involves the C-C breaking of acetic acid into methanol, followed by the complete elimination. These results demonstrate that the surface modification in photocatalyst plays a pivotal role in improving ROS generation and photocatalytic performance, offering a robust and sustainable solution for indoor air purification under visible light.