N-Cdots-decorated TiO2(B)/anatase microspheres with high photocatalytic performance in visible light.

Nitrogen-doped carbon dots (N-Cdots) with enhanced absorption in visible light region were combined with TiO 2 (B)/anatase (TiO 2 (A + B)) microspheres consist of nanosheets via a one-step synthesis. The successful connection of N-Cdots and TiO 2 substrate was confirmed by the appearance of new Ti–O–C bond. The degradation rate of Rhodamine B (RhB) for N-Cdots@TiO 2 (B)/anatase was improved to seven times higher than that of initial TiO 2 (B) microspheres under full spectrum illumination. N-Cdots@TiO 2 (B)/anatase photocatalyst also exhibited high photocatalytic ability under visible light irradiation. The possible mechanism was proposed in two irradiation conditions. N-Cdots act as a semiconductor to generate electrons and holes. The electrons were transferred to the conduction band of TiO 2 (B) and anatase, which improved the visible light utilization efficiency. Meanwhile, the heterophase structure of TiO 2 (A + B) substrate restrained the recombination of electron-hole pairs. It is the synergistic effect of heterophase and N-Cdots that enhanced the photocatalytic performance. Image 1 • TiO 2 (B)/anatase microspheres loaded with N-doped carbon dots (N-Cdots) were prepared. • N-Cdots connected with TiO 2 via Ti–O–C bond rather than simple adsorption interaction. • N-Cdots act as a semiconductor to generate electron-hole pairs and enhanced photocatalytic in visible light. • The synergistic effect of N-Cdots and TiO 2 (B)/anatase elevated photocatalysis in full spectrum. [ABSTRACT FROM AUTHOR]