The design and realization of a large-area flexible nanofiber-based mat for pollutant degradation: an application in photocatalysis

This work demonstrates a novel multifunctional nanofibrous mat for photocatalytic applications based on TiO2 nanocables functionalized by Ag nanoparticles and coated with a thin (similar to 2 nm) graphitic shell. In this mat, which was realized by an electrospinning technique, each component serves a unique function: the carbon coating acts as both an adsorption material for capturing pollutants and as a charge-transfer material, the Ag nanoparticles act as a visible-light sensitizing agent and also as a charge-transfer material, finally the TiO2 nanocable mat acts as a UV sensitive photocatalytic matrix and as the flexible substrate for the other functional components. This multicomponent nanocable mat exhibits excellent photocatalytic activity under simulated solar irradiation for the degradation of model pollutants including RhB and phenol. The significant photocatalytic properties are attributed to the synergetic effect of the three functional components and the unique charge transport "freeway" property of the nanofibrous mat. In addition, the porous carbon coating infiltrated into the nanocable matrix endows the mat with excellent flexibility and enables robust, large-area (10 x 10 cm) fabrication, representing a significant advantage over previous brittle ceramic nanofibrous mat photocatalyst substrates. This study provides new insight into the design and preparation of an advanced, yet commercially practical and scaleable photocatalytic composite membrane material. The as-prepared photocatalytic mat might also be of interest in solar cell, catalysis, separation technology, biomedical engineering, and nanotechnology.