Spray-Drying Synthesis of Ball-Like ZnO Assembly Composed of ZnO Nanoparticles for Highly Efficient Photocatalysis

In this paper, ball-like ZnO assemblies composed of ZnO nanoparticles were prepared by a spray drying method and showed potential as a photocatalyst. The process included preparing a zinc acetate solution, then producing a ZnO precursor, and then sintering the precursor to obtain the ball-like ZnO assemblies. With an increase in the calcination temperature, the crystallinity degree could be improved along with an increase in the crystallite size. Scanning electron microscopy (SEM) analysis showed zinc oxide formed micron sized spherical structures by agglomeration. The effects of the calcination temperature of ball-like ZnO on the degree of photodegradation have been investigated. Experimental results showed that when the ball-like ZnO assemblies were employed as photocatalysts, the increase of the temperature led to the decrease of the degradation rate of methyl orange.