Nitrogen-induced TiO2 electric field polarization for efficient photodegradation of high-concentration ethyl acetate: Mechanisms and reaction pathways

Volatile organic compounds (VOCs) posed a significant threat to the sustainability of ecosystems and human health, and photocatalytic oxidation technology emerged as one of the promising strategies. In this work, N-doped TiO composites were prepared by ball milling utilized melamine as a precursor for the photodegradation of high-concentration ethyl acetate under visible light. The electric field polarization effect of TiO facilitated the exposure of active sites, promoting separation and migration of photogenerated carriers. DFT calculations further demonstrated that N–TiO possessed better electron transition capabilities and stronger pollutant adsorption abilities. Notably, the optimized N–TiO (9-N-P25) exhibited an ethyl acetate removal rate of up to 98.8 % (2000 ppm) under visible light irradiation, and the speed constant k values (0.09488 min) was 2.66 folds higher than that of pure TiO (0.03571 min). The ·O and ·OH free radicals played major roles in the photodegradation process, and the interaction mechanism between free radicals and pollutant molecules was analyzed through in-situ infrared. Additionally, the mechanism of photocatalytic degradation of ethyl acetate by N–TiO was further elucidated. This work provided new insights into the semiconductor photodegradation of high-concentration VOCs, offering novel pathways for removing VOCs in the atmospheric environment.