ABSTRACT
ZnO nanoparticles of rod-like architecture have excellent potential to be used in wastewater treatment as a photocatalyst. They were synthesized by utilizing sonochemical/hydration- dehydration techniques using glutamine as a biotemplate. The effects of calcination temperatures, that is, 300°C, 500°C, and 700°C, on the crystallinity, optical properties, and photocatalytic activity of synthesized zinc oxide nanoparticles were investigated. X-ray diffraction (XRD) results indicated that all calcinated samples have a crystalline hexagonal wurtzite structure. Morphology and elemental compositions were investigated using field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. The XRD and Fourier transform infrared (FTIR) spectra revealed that the samples were amorphous at 100°C; however, it changed into a crystalline structure amid the calcination process. Optical properties were determined using a UV-visible reflection spectrophotometer and showed abatement in the band gap with increasing annealing temperature. The progress of the photocatalytic degradation was monitored by a UV-visible spectrophotometer, while the mineralization ability was estimated by total organic carbon tests of ZnO-calcinated samples. The effect of various operational parameters the photocatalytic efficiency and rate of dye degradation was studied. High photocatalytic degradation of maxilon blue dye (GRL) was found at pH 6.3.
