Stacked ZnO nanorods synthesized by solution precipitation method and their photocatalytic activity study

ZnO has been considered as a promising photocatalyst for wastewater treatment. Although many works have been done to enhance the photocatalytic activity of ZnO particles, it is difficult to synthesize well-controlled morphology of ZnO particles having high photocatalytic activity. In this work, stacked ZnO nanorods were synthesized at different growth time via solution precipitation method. Their length and diameter of stacked ZnO nanorods increased with growth time. The formation of stacked ZnO nanorods was attributed to the joining of (002) polar surfaces at the tips of a smaller ZnO nanorods during the synthesis process. A small amount of PVP was added to minimize the agglomeration and to reduce the secondary nucleation of ZnO nanorods. The photocatalytic study showed that the photodegradation of RhB solution by stacked ZnO nanorods under UV light followed first-order kinetic. The results also indicated that a larger effective surface area of stacked ZnO nanorods leads to a higher adsorption of organic molecules, causing a better photocatalytic activity for RhB dye removal. Stacked ZnO nanorods synthesized by solution precipitation method and their photocatalytic activity study.