Preparation of three-dimensional porous spherical TiO2@g-C3N4 composites and visible light catalytic degradation on organic dyes

In order to improve the visible light catalytic activity of TiO2, the TiO2@g-C3N4 (TCN) composite catalysts with three-dimensional porous structure and rich active sites were prepared by hydrothermal method and calcination method orderly. The synthesized TCN composites microstructures were thoroughly characterized and their performance for the photocatalytic degradation of organic dyes was investigated. The results show that the prepared composites formed the heterojunctions with a core-shell structure, which can effectively broaden the absorption spectrum of TiO2 to visible light region. In the degradation experiments, the TCN composites exhibited excellent photocatalytic degradation effect on organic dyes, which can reach 99.65% under visible light irradiation for 2 h. The strong acid condition was benefit to the catalytic process. After five cycles of testing, the degradation efficiency of organic dyes can still maintain at 95.62% level, which indicate that the TCN composites had excellent visible light catalytic activity and reusability.