ZnO-Zn/CNT hybrid film as light-free nanocatalyst for degradation reaction

wWe report a newly developed ZnO-Zn/carbon nanotube (CNT) hybrid film, which can function as a light-free nanocatalyst in a degradation reaction. The freestanding ZnO-Zn/CNT hybrid film was prepared by using CNTs and ZnO-Zn powder (consisting of ZnO nanorods (NRs) and a ZnO-Zn heterogeneous structure). The ZnO-Zn heterogeneous structure was obtained by hydrolyzing Zn nanoparticles prepared via roller vibration. The hybrid film exhibited effective catalytic properties in degrading methylene blue (MB) in aqueous solution, without the need for special light control at ambient temperature. It is interesting to note that the degradation efficiency is related to not only the catalyst content, but also the deformation of ZnO NRs induced by different flow velocity. It is believed that the piezoelectric effect of the ZnO NRs plays a crucial role in this degradation process. The faster the solution flows, the larger the deformation of the ZnO NRs embedded in the CNT network. This process induced higher ionic charges which degraded MB more effectively. Such novel material's piezoelectric effect opens a new approach to develop a light-free catalyst to degrade organic contaminant. (C) 2013 Elsevier Ltd. All rights reserved.