Synthesis of ZnO-nanoparticles by microwave assisted sol-gel method and its role in photocatalytic degradation of food dye Tartrazine (Acid Yellow 23)

ZnO- nanoparticles with an average particle size of 24 nm were successfully synthesized using the microwave assisted sol- gel technique. Structural and morphological properties of the nanoparticles were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), Energy disperse spectrum (EDS) and Fourier transform infrared spectroscopy (FTIR). The band gap energy was measured to be 3.27 eV. The photocatalytic degradation of tartrazine has been studied in aqueous solution under UV-C irradiation at different pH values, catalyst doses, and tartrazine concentration. Degradation of samples was monitored by a spectrophotometer. Results have shown that 95% of 50 mg L-1 tartrazine was degraded in 120 min due to the photocatalytic degradation in presence of 0.02 g of ZnO-nanoparticles. The photocatalytic degradation kinetics has also been investigated. The experimental data were fitted very well in the pseudo-first-order kinetic and Langmuir-Hinshelwood models.