Hierarchical polyurethane/RGO/BiOI fiber composite as flexible, self-supporting and recyclable photocatalysts for RhB degradation under visible light

Increasing organic pollutants have seriously affected the ecological environment and human health, photocatalytic technology is considered as one of the most effective and environmentally friendly treatment methods. In this work, a novel hierarchical polyurethane (PU)/reduced graphene oxide (RGO)/bismuth oxyiodide (BiOI) composite fiber photocatalyst is constructed via an energy-saving route consisted of ultrasonic-assisted and co-precipitation method by utilizing PU nanofibers as substrate. The RGO are first evenly wrapped in the PU nanofiber surface and BiOI nanosheets are then uniformly grown on the PU/RGO surface to form the hierarchical PU/RGO/BiOI composite fibers with a core–shell structure. The composition, morphology and electrochemical performance of the obtained PU/RGO/BiOI were characterized by XRD, XPS, SEM, BET, I-t and EIS. Benefited from the high specific surface area of the PU nanofiber and the excellent electron transfer ability of the RGO, a remarkable photocatalytic activity was achieved for the PU/RGO/BiOI composite fibers and the degradation rate of RhB is 93.2% within 180 min. Notably, compared to the traditional suspended nanoparticles, the PU/RGO/BiOI fibers exhibit excellent flexibility and self-supporting property, and can be easily separated and recovered from the contaminated water. Thus, the obtained PU/RGO/BiOI composite fibers with high photocatalytic activity and easily separable property are expected to possess great potential in water purification.