Porous TiO/Carbon Dot Nanoflowers with Enhanced Surface Areas for Improving Photocatalytic Activity.

Electron-hole recombination and the narrow-range utilization of sunlight limit the photocatalytic efficiency of titanium oxide (TiO). We synthesized carbon dots (CDs) and modified TiO nanoparticles (NPs) with a flower-like mesoporous structure, i.e., porous TiO/CDs nanoflowers. Among such hybrid particles, the CDs worked as photosensitizers for the mesoporous TiO and enabled the resultant TiO/CDs nanoflowers with a wide-range light absorption. Rhodamine B (Rh-B) was employed as a model organic pollutant to investigate the photocatalytic activity of the TiO/CDs nanoflowers. The results demonstrated that the decoration of the CDs on both the TiO nanoflowers and the (commercially available AEROXIDE TiO) P25 NPs enabled a significant improvement in the photocatalytic degradation efficiency compared with the pristine TiO. The TiO/CDs nanoflowers, with their porous structure and larger surface areas compared to P25, showed a higher efficiency to prevent local aggregation of carbon materials. All of the results revealed that the introduced CDs, with the unique mesoporous structure, large surface areas and loads of pore channels of the prepared TiO NPs, played important roles in the enhancement of the photocatalytic efficiency of the TiO/CDs hybrid nanoflowers.