Morphological effect of one-dimensional ZnO nanostructures on the photocatalytic activity

Abstract

The chemical and physical properties, including photocatalytic activity, can be tuned by altering the morphology of the ZnO nanostructures. Herein, the correlation between the physical properties (optical and shape) of various one-dimensional (1-D) ZnO and their photocatalytic performance was evaluated. The 1-D ZnO nanostructure (nanorods (NRs), nanowires (NWs), and nanotubes (NTs)) on a glass substrate were successfully synthesized using a hydrothermal method with varying precursor concentrations and reaction temperatures. By reducing the seeding precursor concentration, the morphology of ZnO changed from NRs to NWs, whereas the NRs were transformed into NTs when the incubation time was prolonged. XRD and SEM analysis confirmed the formation of hexagonal wurtzite ZnO NRs, NWs, and NTs with trunk diameters of 151 nm, 60 nm, and 157 nm, respectively. Furthermore, the UV-light photocatalytic efficiency test using methylene blue exhibited that the one with the highest degradation efficiency was ZnO NTs (67.43%), followed by ZnO NWs (53.76%) and ZnO NRs (46.10%). The morphology and physicochemical properties study revealed that the large polar face owned by ZnO NT, which is augmented by the high UV absorption and large photocurrent density, enhanced their photocatalytic efficiency.