Green Synthesis of SnO2 Nanoparticles on Bentonite and Study of Its Photocatalytic Activity for Degradation of Eriochrome Black T

In this study, thyme extract was used for green synthesis of tin oxide nanoparticles on bentonite (SnO2 NPs@bent). The aqueous extract of thyme was applied as an effective reducing agent and a green stabilizer in this synthetic approach. SnO2 NPs@bent was characterized by various methods such as infrared Fourier spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray energy diffraction spectroscopy (EDS). After the assurance of the successful synthesis of tin oxide nanoparticles on bentonite, its photocatalytic activity was investigated for the degradation of the organic dye of eriochrome black T, under direct sunlight. The new catalyst exhibited a good catalytic activity, so that the related peak to the eriochrome black T in the UV spectrum decreased over time, until it disappeared completely after 5 hours. In this study, no chemicals or toxic solvents were used, neither in stage of the catalyst production nor in stage of the organic dye degradation, and all conditions were green and safe.