A multifunctional noble-metal-free catalyst of CuO/TiO2 hybrid nanofibers

Exploiting photocatalysts/catalysts with characteristics of low cost, high reactivity and easy recovery is of great significance for energy efficiency and environmental remediation. Herein, CuO/TiO2 hybrid nanofibers with different CuO contents were fabricated by a simple and low-cost method of electro-spinning followed with calcinations in air. The hybrid nanofibers possess some distinct merits including mesoporous structure, extended light response range, and large TiO2/CuO interface. The CuO/TiO2 hybrid nanofibers showed improved photocatalytic activity for organic dye degradation under both simulated sunlight (UV-vis) and visible light (lambda > 420 nm), compared with pure TiO2 nanofibers. Both processes exhibited humplike activity dependence upon CuO addition, with a peak at 1 wt.%-CuO content under UV-vis light and a peak at 5 wt.%-CuO content under visible light, respectively. The mechanism for the CuO-content dependent photocatalysis was discussed with the photoelectrochemical analysis in evidence. Moreover, the CuO/TiO2 hybrid nanofibers exhibited very high catalytic efficiency for the reduction of nitrophenols by sodium borohydride, and the apparent reaction rate constants ascended with the increased CuO content. The optimized CuO/TiO2 nanofibers are expected to act a highly efficient catalyst to replace the noble metals in this field. Therefore, this work demonstrated a convenient case for the exploitation of noble-metal-free catalysts with high efficiency, to meet the increasing demands of industrial applications at reduced costs. (C) 2016 Elsevier B.V. All rights reserved.