Intrinsic carbon-doping induced synthesis of oxygen vacancies-mediated TiO2 nanocrystals: enhanced photocatalytic NO removal performance and mechanism

Abstract Herein, we developed a facile approach to fabricate oxygen vacancies-mediated TiO2 (OVs-TiO2) nanocrystals via an intrinsic carbon-doping induced strategy. The intrinsic carbon-doped TiO2 nanocrystals were firstly synthesized by water-controlled-releasing solvothermal (WCRS) process using ethanol, acetic acid and titanium tetraisopropoxide (TTIP) as precursors. The carbon-doped TiO2 was calcined at 325 °C under N2 atmosphere to introduce the OVs. The obtained OVs-TiO2 displayed outstanding photocatalytic NO removal performance under visible light irradiation (λ˃510 nm), in comparison with the commercial P25. With the aid of DFT calculations, we revealed that the intrinsic carbon-doping was beneficial for the formations of OVs in carbon-doped TiO2. Moreover, the OVs played crucial roles in improving light absorption, facilitating charge separation, and activating surface reactions to enhance the photocatalytic NO removal performance.