BiOI/PPy/cotton photocatalytic fabric for efficient organic dye contaminant degradation and self-cleaning application

Water pollution caused by industrial organic dyes poses a serious threat to human health and the ecological environment. Natural cellulose fibers functionalized with photocatalysts are regarded as promising materials for removing organic dyes. However, the immobilized photocatalysts usually exhibit a high recombination rate of photo-generated charge carriers, which seriously reduces the photocatalytic efficiency. Herein, a photocatalytic functional cotton fabric was prepared by a two-step process, including in-situ gas-phase polymerization of pyrrole and layer-by-layer self-assembly process of bismuth oxyiodide. The conjugated molecular structure of polypyrrole (PPy) conductive polymer could effectively facilitate the separation of photo-generated electron-hole pairs of bismuth oxyiodide photocatalyst on the fiber surface. The ability of composite fabrics to absorb visible light was greatly enhanced. The photocatalytic functional fabric exhibited a high photocatalytic degradation efficiency towards organic dye contaminants. On the other hand, the PPy nano-layers on cotton fibers induced bismuth oxyiodide nanosheets to self-assemble a more dense porous structure, which trapped a large amount of tiny air. The prepared fabric exhibited an obvious superhydrophobicity with a water contact angle above 150° and an excellent self-cleaning ability toward liquid/solid contaminants. This work provides a new insight into water treatment through the development of efficient photocatalytic textiles.