Synthesis and application of TiO2/SiO2/rGO photocatalyst for photochemical degradation of erythromycin in aqueous solutions

Today, the widespread use of antibiotics in the treatment of various infections leads to the accumulation of these substances in water and wastewater which in turn causes numerous environmental and health issues. The aim of this study was to evaluate the efficiency of TiO2/SiO2/rGO photocatalyst in removing erythromycin as a representative antibiotic from aqueous solutions.

The present study is an experimental-applied research. TiO2/SiO2/rGO nanoparticles were synthesized as a photocatalyst by sol-gel method and were characterized using different techniques such as FE-SEM, XRD, FT-IR, EDS and TEM. The effects of pH, photocatalyst dose, H2O2 concentration and reaction time on the photochemical removal process of erythromycin were studied. The removal efficiency was determined by UV-Vis spectroscopy at 298 nm.

The characterization results well confirmed the synthesis of TiO2 and SiO2 nanoparticles in the range of 20 to 25 nm on the surface of reduced graphene oxide nanoparticles. The results of optimization showed that the process of photocatalytic degradation of 25 mg/L erythromycin at pH = 7.4, 30 mg nanocomposite, 5 mg/L H2O2 for 140 min irradiation was complete. In comparison, in the presence of TiO2 nano photocalyst less than 4% of the pollutant degradation was achieved in the above conditions.

The results showed that the synthesized TiO2/SiO2/rGO nanocomposite is an effective catalyst in the process of photocatalytic degradation of erythromycin from aqueous solutions and the proposed method are more cost-effective than similar methods.