Nanometric-sized titanium oxide (TiO2) powders were synthesized through two emulsions method. In which two solutions of reverse emulsion, one containing Ti4+ chelated with citric acid/cellulose aqueous droplets and the other aqueous ammonia droplets, with the same water/oil (w/o) ratio are mixed together to form a slurry of titanium citrate precursor. Then the precursors were recovered and calcined to form TiO2 at various temperatures. The powders prepared from volume ratio of w/o at 1/100 had a relatively uniform and spherical with less aggregation. When the volume ratio of w/o was increased, the particle size had more aggregation and bigger. The particle sizes of powders obtained from volume ratio of 1/100 were estimated to be 6-8 nm. Finally, photocatalytic experiments for water splitting and producing hydrogen was examined in methanol solution by utilizing 65 mg nanometric-sized Pt (0.6 wt%)/TiO2 powder, and about 70 micromol hydrogen was produced in 6 h.
Journal of Nanoscience and Nanotechnology 9(6),3843-3847