Synthesis of black TiO2 with efficient visible-light photocatalytic activity by ultraviolet light irradiation and low temperature annealing

•In this work, we have prepared black titanium dioxide (B-TiO2) nanoparticals in combination with ultraviolet light and low temperature annealing. This method is simple, efficient and environmentally friendly.•The synthesis mechanism of the black B-TiO2 nanomaterials was analyzed by combining the different characterization data with the first-principles calculation results.•The Ti-O lattice and structure of the B-TiO2 sample did not change after low-temperature annealing.•The process of H-doping results in a reduction of the localized Ti3+ states, that are also the recombination centers of excited electrons and holes.•These nanoparticles can absorb a amount of visible light and degrade the organic pollution.