Engineering of ZnO nanostructures for efficient solar photocatalysis

Abstract

Highly photoactive metal oxide catalyst can be developed by engineering the nanostructure of the material. The present study reports the engineering of ZnO nanostructures using the microwave technique. The physicochemical characterization reveals the role of microwave irradiation power and reaction temperature on ZnO nanostructure engineering. The structural and surface analyses of the samples prepared at room temperature and 180 °C, in various microwave power, confirms the formation of nanorods. The higher reaction temperature has favored the nanorods to a flower like structures and increase in microwave power leads to the formation of denser, uniform nanoflowers, with enlarged petal diameter. The photocatalytic performance of the samples was evaluated using Methylene Blue (MB) as probe pollutant under solar irradiation. All the samples showed relatively high photocatalytic performance in terms of rate constant and photonic efficiency. However, the sample prepared at 180 °C and 360 W showed superior photocatalytic performance than the rest, which can be attributed to the effective photon absorption along with reduced charge carrier recombination. This study opens a new low-cost method for engineering the nanostructure for improving the photocatalytic performance.