Synthesis and characterization of SnO2 nanoparticles and photocatalytic activitiy study in methylene blue dye and toxic chromium(VI) heavy metal

Photocatalyst; convert toxins to non-toxin organic and inorganic compounds. The most known photocatalyst TiO2 is a low efficient photocatalyst owing to its fast recombination rate and needed high energetic photon to excite. An efficient photocatalyst should be excited easily with low energy and after excited, having slow recombination rate. In this context scientists focused on new photocatalysts. Tin dioxide (SnO2) is n-type semiconductor photocatalyst. In this work, SnO2 nanoparticles have been successfully synthesized in aqueous medium in the presence of diethylene glycol via simple chemical precipitation method for the first time. The structural, morphological and chemical characterizations were investigated by using FT IR, XRD, SEM and EDX methods. The photocatalytic activity of the synthesized material was investigated by the decolorization of methylene blue dye and reduction of toxic chromium(VI) to non-toxic sample under UV or halogen light irradiation as followed by spectrophotometric monitoring at room temperature. The decolorization efficiency of MB dye solution after 20 min exposure time is 100% under UV light where efficiency of SnO2 is 94% after 120 min under visible light irradiation. Photocatalyst load is a little amount of photocatalyst (0.6 g/L). The reduction efficiency of chromium(VI) after 10 min exposure time is 100% under UV light where efficiency of SnO2 is only 93% after 120 min under visible light irradiation. Photocatalyst load is a little amount of photocatalyst (0.4 g/L). At the end, reusage tested 5 times and it shows that our photocatalyst is stable. Keywords: chromium(VI), methylene blue, photocatalysis, SnO2, textile wastewater treatment