incorporation of 12-tungstophosphoric acid in titania spheres and fabrication of core-shell polyoxotungstate/titania nanostructures

core-shell 12-tungstophosphoric acid/tio2 (hpw/tio2) nanoparticles at 10 and 20% of hpw have been synthesized by simple in-situ sol- gel method. characterization of the samples was carried out by x-ray diffraction (xrd), scanning electron microscopy (sem), fourier transform infrared (ftir). the x-ray diffraction patterns of as prepared solid samples, indicated characteristic peaks of titania with additional peaks concerning to hpw in a very low intensities. this result in addition to the ftir and sem - edx analysis data confirmed incorporation of hpw / tio2 nanostructure in spherical morphology with a particle size of around 25 nm.