Photocatalytic Activity of Pure and Zinc Doped Tin Oxide Nanoparticles Synthesized by One Step Direct Injection Flame Synthesis

A very simple and rapid Direct Injection Flame Synthesis (DIFS) method is effectively used to synthesize pure tin oxide (SnO 2 ) and zinc doped tin oxide (Zn:SnO 2 ) nanoparticles from the metallic tin (Sn) and zinc (Zn) powders for the photocatalytic degradation of methylene blue (MB) dye. The DIFS nanoparticles were characterized using XRD, Raman, UV–Vis, FESEM, PL and EDX studies. The X-ray diffraction analysis indicated that the synthesized SnO 2 and Zn:SnO 2 nanoparticles have pure tetragonal phases and their average crystallite size decreases when Zn was doped with SnO 2 . Raman study confirmed the various mode of vibrations and the crystal structure of the synthesized nanoparticles. Purity, atomic percentage and chemical composition were analysed using Energy dispersive X-ray analysis and found to be free from impurities. The band gap energy increases from 3.5 to 3.6 eV upon doping which was revealed from the UV–Visible spectroscopic analysis. Photoluminescence analysis confirms the red shifted emission for Zn:SnO 2 due to the oxygen deficiency. The CIE chromaticity (x,y) for SnO 2 and Zn:SnO 2 was calculated from the emission spectra and the co-ordinates represents blue and violet region respectively. Field Emission Scanning Electron Microscopy analysis showed that the pure SnO 2 nanoparticles have irregular, agglomerated, nanoflowered and nanoclustered formation whereas Zn:SnO 2 nanoparticles has more crystalline, cubical and nanoflake structure. The photocatalytic activity was enhanced due to the presence of Zn in SnO 2 under UV light irradiation. The efficiency of MB degradation by SnO 2 was found to be 82% and enhanced to 88% upon doping. Thus the Zn doped SnO 2 nanoparticles synthesized by DIFS was found to be an effective photocatalyst than the pure SnO 2 .