Growth of black TiO2 nanowire/carbon fiber composites with dendritic structure for efficient visible-light-driven photocatalytic degradation of methylene blue

The utilization of solar energy and recombination of electron-hole pairs are two major barriers that significantly limit the use of TiO2 in photocatalysis. In this article, dendritic TiO2/CF composites, which significantly improve the adsorption ability and maximize light-harvesting efficiency, were synthesized by hydrothermal method. With further reduction by hydrogen, black TiO2/CF composites were obtained, which have extended photoresponse range due to the produced surface defects and oxygen vacancies. In the photocatalytic degradation of methylene blue, the black TiO2/CF composites show greatly enhanced photocatalytic ability compared with the white ones. The improved photocatalytic efficiency could be owned to three aspects: the improved adsorption ability, the enhanced light absorption, and the introduced oxygen vacancies and defects in the surface layer of black TiO2. This study indicates the great potential of these black TiO2/CF composites in photocatalysis and related areas, and provides a new strategy to synthesize photocatalysts with enhanced photocatalytic efficiency.