Novel quantum dot and nano-sheet TiO2 (B) composite for enhanced photocatalytic H2 - Production without Co-Catalyst

Recently, the production of hydrogen through water splitting using titania (TiO2) as photocatalyst has received great attention in the new energy field. In this work, a single one-step hydrothermal method is used to synthesize ultra-thin TiO2 (B) nano-sheets, anatase TiO2, and their composite, using ethylene glycol (EG) and ethanol as the solvent. A new composite nanostructure with anatase TiO2 quantum dots grown on TiO2 (B) nano-sheets is obtained at certain ratios between EG and ethanol. Even without the help of co-catalyst, a high photocatalytic efficiency, about 45 times of that of rutile-anatase mixed Degussa P25, is observed in the TiO2 (B)-anatase composite nanostructure. The outstanding performance can be attributed to its large specific surface area, abundant surface active sites, mixed phase promoted efficient charge separation. Moreover, the properly aligned band structure, with the conduction band level of ultra-thin TiO2 (B) about 0.6 eV higher than that of the anatase, provides a large driving force for the reduction of water.