Ultrasound-assisted phyto-mediated synthesis of SnO2 nanoparticles as photocatalyst in tetracycline photocatalytic oxidation

Antibiotic-containing wastewater from pharmaceutical industries have become serious organic pollutants need to be serious treated, and one of the important antibiotics is tetracycline (TC). Advanced oxidation process (AOPs) including photocatalytic oxidation is recognized as efficient method. Respect to the emergence of nanomaterials utilization in many aspects, syntheses of nanoparticles and nanomaterials photocatalyst are also developed. With consideration of green chemistry approach, in this research, phyto-mediated synthesis of SnO2 nanoparticles (SnO2 NPs) by using Tinosphora cordifolia stem extract with the applied ultrasound irradiation method was conducted. Study on the effect of calcination temperature to the physicochemical feature and photocatalytic activity towards TC photooxidation were focused. The NPs samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), and x-ray photoelectron spectroscopy (XPS). The results showed a single phase SnO2 produced at two varied calcination temperature of 200 degrees C and 500 degrees C with the particle size ranging at 2-7 nm, and 5-15 nm, respectively. Both samples exhibited the high photocatalytic activity for TC photooxidation under UV and visible light exposure as the degradation efficiency of 97.9 % was achieved by NPs calcined at 200 degrees C under UV light, meanwhile the efficiency achieved by visible light exposure was 55.7 %. In summary, reported procedure for SnO2 NPs synthesis using the extract and ultrasound-irradiation intensification was a potential method to be developed due to its fast, efficient, environmental-friendly, and timeeffectiveness for providing high active photocatalyst in organic compounds-contaminated wastewater.