A Facile Strategy for the Preparation of N-Doped TiO 2 with Oxygen Vacancy via the Annealing Treatment with Urea.

Although titanium dioxide (TiO 2 ) has a wide range of potential applications, the photocatalytic performance of TiO 2 is limited by both its limited photoresponse range and fast recombination of the photogenerated charge carriers. In this work, the preparation of nitrogen (N)-doped TiO 2 accompanied by the introduction of oxygen vacancy (Vo) has been achieved via a facile annealing treatment with urea as the N source. During the annealing treatment, the presence of urea not only realizes the N-doping of TiO 2 but also creates Vo in N-doped TiO 2 (N-TiO 2 ), which is also suitable for commercial TiO 2 (P25). Unexpectedly, the annealing treatment-induced decrease in the specific surface area of N-TiO 2 is inhibited by the N-doping and, thus, more active sites are maintained. Therefore, both the N-doping and formation of Vo as well as the increased active sites contribute to the excellent photocatalytic performance of N-TiO 2 under visible light irradiation. Our work offers a facile strategy for the preparation of N-TiO 2 with Vo via the annealing treatment with urea.