Photocatalytic degradation of Rhodamine dyes using zinc oxide nanoparticles

This paper presents the synthesis of nanocrystalline zinc oxide (ZnO) particles via the sol-gel method using zinc acetate as precursor. The calcination temperature of the ZnO was varied to determine its effect on particle size. The resultant samples were characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR), UltraViolet-visible Spectroscopy (UV-Vis) and Scanning Electron Microscopy (SEM). Nanocrystalline wurtzite ZnO particles were produced with crystallite size ranging from ~16 nm to ~30 nm. Energy Band gap of the synthesized zinc oxide nanoparticles decreased with increasing calcination temperature and crystallite size. SEM Micrographs showed rice-like microstructure morphology of ZnO nanoparticles. The usage of the ZnO nanoparticles as a photocatalyst was also explored in the degradation of Rhodamine B dye using UV - light with particular attention to the effect of particle size and catalyst load on the degradation efficiency of the dyes. The nanoparticles calcined at 400 °C with crystallite size of 16 nm resulted in the highest degradation efficiency of ~95.41% when 0.2 g catalyst loading was applied.