Comparison of ball milling-hydrothermal and hydrothermal methods for synthesis of ZnO nanostructures and evaluation of their photocatalytic performance

Zinc oxide nanostructures with different morphologies, were successfully synthesized by two methods (hydrothermal and ball mill-hydrothermal), and characterized by common techniques. The effects of the ball mill and base type on the photocatalytic activity of ZnO nanostructures synthesized by each methods were evaluated for phenazopyridine (PhP) degradation. ZnO nanoparticles with quasi-prismatic morphology (synthesized by ball mill-hydrothermal and KOH) displayed a higher photocatalytic activity (45%) than the other ZnO nanostructures. The ball milling before hydrothermal process caused changing in the morphology, increasing the specific surface area, and improving the photocatalytic activity as well as changing the optical properties.