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 2 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 2 facilitated the exposure of active sites, promoting separation and migration of photogenerated carriers. DFT calculations further demonstrated that N–TiO 2 possessed better electron transition capabilities and stronger pollutant adsorption abilities. Notably, the optimized N–TiO 2 (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 −1 ) was 2.66 folds higher than that of pure TiO 2 (0.03571 min −1 ). The ·O 2 − 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 2 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.