synthesis of zno/bi2o3 and sno2/bi2o3/bi2o4 mixed oxides and their photocatalytic activity

in the present work, zno/bi2o3, sno2/bi2o3/bi2o4 mixed oxide, bi2o3 rod-like and sno2 nanoparticle have been synthesized. the obtained samples were characterized by field emission scanning electron microscopy (fe-sem) and x-ray diffraction (xrd). the optical properties of samples were evaluated by uv-vis spectrophotometer. the photocatalytic activity of samples was evaluated by decolorization of methylene blue (m.b.) solution. the present work indicates the improving or hampering effect of bi2o3 on the photocatalytic activity of zno/bi2o3. the results show that the photocatalytic performance of zno/bi2o3 which is higher than that of bi2o3, sno2, and sno2/bi2o3/bi2o4 is related to the presence of the zinc oxide semiconductor. furthermore, results indicated that the photoactivity of the sno2/bi2o3 system was not improved. the present work affirms the importanat position of energy levels and also the separation of photogenerated electron/hole pairs on the efficient photocatalytic performance.