Photocatalytic Degradation of Methylene Blue by CeO۲ nanoparticles

Over the last decades, the removal of wastewater using active photocatalytic systems has attracted considerable attention, which has led to the development of various nanostructured catalysts for treatment of wastewater. In this regard, the role of pollution of toxic and non-degradable organic dyes that leave their destructive effects on the environment for a long time is undeniable. These compounds are widely used in the textile, leather, paper, food, plastic and cosmetic industries. Methylene blue dye is a multi-nuclear aromatic compound that can not only cause acute toxic effects, but also cause some serious problems such as shortness of breath, chest pain, dizziness, syndrome, burning sensation, nausea, vomiting and diarrhea. In this project, the CeO۲ nanoparticles were prepared using simple Co-precipitation method. Synthesized CeO۲ nanoparticles were characterized by XRD, FESEM & DRS technique. The effect of key parameters such as initial pH, photocatalyst dosage, initial dye concentration and irradiation time on dye removal efficiency were studied. The results of dye removal show that the initial dye concentration has no effect on the removal percentage, but by increasing the pH of solution, the amount of dye removal was increased, and the maximum efficiency was achieved at pH=۸. Also, by increasing the photocatalyst dosage from ۰.۰۱ to ۰.۰۵ mg/۱۰۰mL and increasing the irradiation time from ۱۰ to ۳۰ minutes, the color removal efficiency was increased. Maximum photocatalytic degradation of Methylene Blue was about ۷۱.۷۶% at pH=۳, ۳۰ mg/L of initial Methylene Blue concentration, ۰.۰۵ mg/۱۰۰mL of CeO۲ nanoparticles at ۳۰ min of irradiation time. However, the results indicated that the photocatalytic degradation of Methylene Blue best fitted with pseudo-first order kinetic model. According to the experiments, the CeO۲ nanoparticles has high potential for removal of Methylene Blue under UV light (۳۰۰ watt).