alimorad rashidi - nanotechnology research center
mahshad alaei - nanotechnology research center
alireza mahjoub - department of chemistry faculty of science tarbiat modares university

tungsten trioxide nanoparticles with two defferent sizes (average particle size about 50 and 80nm) were prepared by the spray pyrolysis method.photo degradation of congo red azo dye showed that photo catalytic property of the as -prepared WO3 nanoparticles with average size about 80 nm higher than the sample with average size about 50nm. photo degradationof rhodamine B cationic triarylmethane dye showed that photo catalytic property of the as - prepared WO3 nanoparticles with average size about 50nm is higher than the sample with average size about 80nm. the samples were characterized with X-ray diffraction XRD , scanning electron microscopy SEM, EDX analysis and UV -visible spectrum. different interatcions between dyes and the photo catalyst surface, probably causes the inverse behavior of WO3 nanoparticles with two different sizes in congo red rhodamine B photo degradation reactions.

WO3,photo degradation, rhodamine B,congo red