Realizing improved defect-mediated charge separation by assembling C–TiO2-X nanodots into nanostructured microspheres

Abstract

Nanostructured C–TiO2-X microspheres were prepared by facile modified solvothermal method and employed as an efficient visible light photocatalyst for photocatalytic antibiotic elimination. The acetone as well as distilled water not only induced the high crystallization of nanostructured C–TiO2-X microspheres, the formation of C–TiO2-X nanodots, and oxygen vacancies, but also boosted the assembling of C–TiO2-X nanodots into nanostructured microspheres. The photocatalytic performance of nanostructured C–TiO2-X microspheres was evaluated by photocatalytic antibiotic degradation under visible light and Xe lamp irradiation. The prepared C–TiO2-X microspheres showed highly improved visible light absorption, charge separation, and visible light photocatalytic activity. The visible light photocatalytic activity of nanostructured C–TiO2-x-180 microspheres was approximately 3.14 times of commercial TiO2, which could be attributed to the construction of unique nanostructures, oxygen vacancies, and carbon doping for efficient solar light harvesting and utilization, the diffusion of degraded products, and charge separation. Besides, the detailed energy band structures, active species for visible light photocatalytic tetracycline degradation, and visible light photocatalytic mechanism of nanostructured C–TiO2-X microspheres were also proposed in the work.