Flexible and porous TiO2/SiO2/carbon composite electrospun nanofiber mat with enhanced interfacial charge separation for photocatalytic degradation of organic pollutants in water

Semiconductor photocatalysis has long been considered as a promising approach for remediation of polluted water. However, the high recombination rate of electrons and holes, as well as a low reaction rate, have impeded its large-scale applications. Therefore, it is of great importance to develop appropriate photocatalysts for promoting its practical application. In this study, a novel TiO2/SiO2/carbon electrospun nanofiber mat (TSC NFM) with flexibility and porous hierarchy has been successfully designed and fabricated by a facile method of electrospinning and carbonization. Characterization results show that the TSC NFM consists of closely-packed and well-distributed anatase (TiO2) nanocrystals, amorphous SiO2 nanoparticles, and carbon with interconnected meso- and macro-pores. The photocatalytic performance of the TSC NFM was evaluated by degrading rhodamine B and 4-nitrophenol in batch systems. The results show that TSC NFM exhibits a higher photocatalytic activity than TiO2/SiO2 nanofiber mat, which does not contain carbon. The enhanced performance of the TSC NFM can be attributed to the improved adsorption capacity toward the organic pollutants due to the presence of carbon and to the enhanced interfacial charge separation between TiO2 nanoparticles and carbon. Besides, the as-prepared TSC NFM displays good stability and reusability. Notably, the flexible TSC NFM can be used in a continuous-flow reactor to efficiently treat wastewater. Our work provides new insights into the fabrication of carbon-based inorganic nanofiber mats, which have great potential in water treatment. (C) 2019 Elsevier Inc. All rights reserved.