Synthesis and characterizations of three-dimensional ordered gold- nanoparticle-doped titanium dioxide photonic crystals

We developed a simple method to prepare gold-nanoparticle-doped titanium dioxide (GTD) sol-gel solution. The optimized GTD sol-gel solutions were a mixture of TEA, titanium (IV) butoxide, HAuCl4, and deionized water in 0.3:1:0.5:3 volume ratios at room temperature. Using this sol-gel solution, we fabricated the GTD photonic crystal structure by infiltrating this solution by dip-coating into a polystyrene (PS) template. It was found that high quality of thin films was obtained by infiltrating twice the PS templates with the synthesized GTD sol-gel solutions. Energy dispersive X-ray spectroscopy and X-ray photoelectron spectra revealed the doping of TiO2 and Au in the GTD photonic crystals. X-ray diffraction showed that TiO2 and Au existed as anatase phase and metallic Au phase, respectively, in the GTD photonic crystals. The results indicated that the gold nanoparticles were doped into the framework of the photonic crystals.