Synthesis of oxygen vacancy-rich black TiO2 nanoparticles and the visible light photocatalytic performance

The oxygen vacancy-rich black TiO2 (B-TiO2) consisted of compactly and densely stacked nanoparticles was prepared by thermal treatment amorphous Ti(OH)(x) in vacuum. A series of characterization were used to investigate the structure, light absorption ability and chemical environment of samples. Phenol was used to evaluate the photocatalytic performance of the materials under visible light irradiation. The results show that the removal rate constant of B-TiO2 in visible light reaches to 0.1316 h(-1), is the 5.2 times of P-25, exhibiting excellent photocatalytic performance. The excellent photocatalytic performance of B-TiO2 possibly results from the large amounts of oxygen vacancies and the special structure. The large amounts of oxygen vacancies expand the visible light scope. And, the compactly and densely stacked nanoparticles aggregation exhibit large specific areas, plentiful pores and high separation efficiency of photogenerated electrons-holes so that the photocatalytic performance of B-TiO2 is enhanced drastically.