Three-dimensional films of photoluminescent polyoxometalates fabricated by a colloidal crystal template

Three-dimensional ordered thin films based on 12-phosphotungstic acid (PW12O40/SiO2) and lanthanide-substituted phosphotungstate (Eu(PW11O39)2/SiO2, Gd(PW11O39)2/SiO2 and Eu(P2W17O61)2/SiO2) were constructed by an inverse opal method, using polystyrene colloidal crystal as a template. The samples were characterized by elemental analysis, XRD, IR spectra, UV–vis diffuse reflectance spectra (DR-UV–Vis) and SEM techniques. These thin films show well-defined lamellar array with inverse opal structure, and lanthanide polyoxometalate thin films exhibit photoluminescent properties.