Enhancing Solar Light-Driven Photocatalytic Activity of Mesoporous Carbon–TiO2 Hybrid Films via Upconversion Coupling

Solar energy conversion has emerged as an attractive pathway in the decomposition of hazardous organic pollutants. Herein, tridoped β-NaYF4:Yb3+,Tm3+,Gd3+ upconversion (UC) nanorods were embedded in a carbon-doped mesostructured TiO2 hybrid film using triblock copolymer P123 acting as a mesoporous template and carbon source. The photoactivity of our novel material was reflected in the degradation of nitrobenzene, as a representative organic waste. The broad-band absorption of our rationally designed UC nanorod-embedded C-doped TiO2 in the UV to NIR range unveiled a remarkable increase in nitrobenzene degradation (83%) within 3 h compared with pristine TiO2 (50%) upon light irradiation. These results establish for the first time a synergetic bridge between the effects of a creative photon trapping TiO2 architecture, improved NIR light-harvesting efficiency upon UC nanorod incorporation, and a simultaneous decrease in the band gap energy and increased visible light absorption by C-doping of the oxide lattic...