Preparation and visible-light photocatalytic property of nitrogen-doped TiO₂ hollow composite microspheres

In order to improve the visible-light photocatalytic property of TiO₂, micrometer polystyrene microspheres were used as template, tetrabutyl titanate was used as precursor, and triethylamine was used as nitrogen source, electrostatic adsorption self-assembly method was applied to prepare the nitrogen-doped TiO₂ hollow composite microspheres with good spherical morphologies whose particle size was 1.20 μm and shell thickness was about 30 nm. The structure and photocatalytic properties were investigated with SEM, XPS, XRD and ultraviolet-visible spectrophotometer. The results show that the entrance of nitrogen into the TiO₂ lattice replaces parts of O and changes the chemical states of Ti and O in the lattice, but has no obvious effect on the crystal structure of TiO₂. The band gap of TiO₂ hollow composite microspheres after nitrogen-doping decreases, nitrogen-doped TiO₂ hollow composite microspheres not only have stronger light absorption ability in ultraviolet region, but also have stronger light response in visible region, the photocatalytic degradation rate of methyl orange is enhanced obviously compared with Degussa P25 nanometer TiO₂. The conclusion has theoretical guiding significance for the application of TiO₂ in photocatalysis research.