Facile construction of N-doped TiO2 nanohybrids with enriched oxygen vacancies for enhanced photocatalytic green hydrogen production

A series of N-doped TiO2 nanohybrids (xN-TiO2) were successfully prepared via a facile solvothermal route by using oleylamine as N source, for enhancing photocatalytic hydrogen evolution reaction (HER). The doped-N atoms induced the generation of abundant oxygen vacancies (OVs). The resulted impurity and defect levels in xN-TiO2 contributed to their narrowed band gap, enhanced visible light response, and promoted separation and transfer of photogenerated carrier. Moreover, the N-doping optimized the distribution of OVs, and therefore affect the conduction band (CB) location of catalyst. Herein, the 3N-TiO2 catalyst with excellent photoelectric properties and appropriate CB location, showed the photocatalytic HER rate of 3984.71 mu mol h- 1 g- 1 under the simulated sunlight irradiation, which was 5.5 and 29.0 times that of the undoped TiO2 and commercial P25, respectively. Meanwhile, the 3N-TiO2 catalyst exhibited the excellent stability and salt-resistance. This work provides a novel insight for the band alignment of photocatalysts by defects regulation, and opens the new possibility for synthesizing N-doped TiO2 catalyst by a more practical and safe method.