Photocatalytic activity of SnO2 nanoparticles in methylene blue degradation

Abstract Nanosized SnO 2 photocatalysts were prepared with a precipitation method and were characterized by performing transmission electron microscopy (TEM), powder X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). The powder XRD results revealed that the SnO 2 nanoparticles have a typical tetragonal rutile (cassiterite) structure and the average crystallite size was found to be approximately 4.5 nm by using the Debye–Scherrer equation. The prepared SnO 2 nanoparticles consist of agglomerated particles with a mean diameter of around 4–5 nm according to the analysis of TEM images. The XAS data confirmed that the prepared samples have cassiterite structures with tin oxidation state of +4. The prepared SnO 2 nanoparticles were found to exhibit approximately 3.8 times higher activity than bulk SnO 2 in the photodegradation of methylene blue. On the basis of a trapping experiment, we developed a possible mechanism for the photodegradation on SnO 2 nanoparticles.