The preparation of nitrogen-doped TiO₂ nanocrystals with exposed {001} facets and their visible-light photocatalytic performances

Anatase TiO₂ with exposed {001} facets has been deepgoingly studied for optimizing its photocatalytic activity. In this study, we synthesized N-doped TiO₂ nanocrystals with exposed {001} facets by sol-gel method and solvothermal method, respectively. The physical and chemical properties of as-synthesized samples, such as morphology, crystal phase, surface elements composition, porous structure, specific surface area, and optical response, were characterized in detail. The photocatalytic performances of all samples were evaluated by photocatalytic decoloration of methylene blue under visible-light irradiation (λ > 420 nm). The results showed that the as-prepared samples present high visible-light photocatalytic performances, which can be ascribed to the excellent crystallization, the enhancement of absorbance in the visible-light region, and the strong adsorption performance, and calcination treatment is helpful to further improve the visible-light photocatalytic performance of N-doped TiO₂ nanocrystals with exposed {001} facets.