Controlled synthesis of nitrogen-doped binary and ternary TiO2 nanostructures with enhanced visible-light catalytic activity

Nitrogen doping in association with a heterostructure not only modifies the band structure of TiO2 to make it more responsive to visible light, but also suppresses charge recombination and leads TiO2 to have enhanced photoactivity. In this paper, we report on the controlled synthesis of nitrogen doped binary and ternary TiO2 nanostructures through a hydrazine-mediated solvothermal approach. The phase, size, and morphology of the samples can be tuned by simply changing the reaction time. Also, the visible-light photoactivity of the samples was evaluated by decomposing methyl orange and formaldehyde in aqueous solution without any external oxidative or reductive radical-generating sources. The as-prepared catalysts exhibit enhanced photocatalytic activity compared to P25 and the undoped counterpart, and the selected catalyst shows high photostability and photoactivity after reuse four times. This new-type TiO2 nanostructures present a promising candidate for applications in photocatalysis, photochemistry, sensors, and solar cells.