synthesis and characterization of sn-doped tio2 nanoparticles and the evaluation of their photocatalytic performance under vis-lights

Dyes are produced as water pollutants in the textile, plastic, and dye industries. many efforts have been made to remove dyes from industrial wastewater. in this area, photocatalytic performance under vis-lights is a useful and effective method. in this study, a series of highly efficient sn-doped tio2 photocatalysts were successfully developed using a simple heat treatment process. three concentrations of sncl2 powder (3%, 5%, and 7 %) were used for the preparation of materials.  the characterizations of resulting materials were distinguished by scanning electron microscopy (sem), diffusion reflection spectroscopy (drs), and x-ray diffraction spectroscopy (edx). also, methyl orange dye was served to indicate the photocatalytic activity of sn-doped material under visible light irradiation. the results indicated that both doped and also pure tio2 have a uniform size. anatase was the only identified phase in all the products, whether doped or un-doped. the resulting sn-doped materials have demonstrated a band gap value range of 3.14 to 2.68 ev in comparison with pure tio2 which shows a value of 3.2 ev. the photocatalytic evaluations indicated that the samples prepared in the presence of 3, 5, and 7% sncl2 have degradation efficiencies of 85%, 85%, and 90%, respectively within 120 min, which are much higher than that of un-doped tio2. the enhancement in the efficiency was attributed to the gap changes in anatase by the incorporation of sn ions into the tio2 lattice structure. compared to pure tio2, which has a band gap of 3.2 ev, the band gap values for doped tio2 ranged from 3.14 to 2.68 ev.