Enhanced Reactant Activation and Transformation for Efficient Photocatalytic Acetone Degradation on SnO₂ via Hf Doping

Abstract Intensified photocatalytic performance through reducing the recombination of electron–hole pairs and enhancing the oxidation capacity is a key challenge in the field of photocatalytic removal of volatile organic compounds (VOCs). Acetone, as one of the emblematical contaminants VOCs, is a general solvent and widely applied in the pharmaceutical industry, contributing severely to air pollution. Most studies of photocatalysis have focused on the photocatalyst efficiency toward pollutant degradation, but the detailed mechanisms of charge separation as well as transfer and photocatalytic acetone oxidation pathways are not revealed clearly. In this work, it is found that hafnium metal doping on the n‐type semiconductor SnO₂ can modify the electronic structures, restrain the recombination of electron–hole pairs, where the hafnium metal ion acts as the activation site, leading to improved oxidation ability to realize efficient acetone degradation. In addition, the specific path toward the acetone degradation is revealed by closely combined active radical detection, in situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical calculation methods. It provides a new perspective about the detailed and comprehensive reaction mechanism of photocatalytic acetone degradation and carriers transfer between pollutants and photocatalysts, which is expected to promote the practical usage of photocatalytic technology for the expeditious removal VOCs.