| Recently, platelike WO3films prepapred by hydrothermal method using tungsten (W) sheet as the precursor has attracted much interest in the field of photoelectric materials due to its merits of low preparation temperature and simple equipment. However, the opaque base of the platelike WO3films limit its utilization in the application. In the paper, platelike WO3films of transparent substrate were prepapred via RF (radio-frequency) sputtering and hydrothermal method. The photoelectrochemical properties of the platelike WO3films were enhanced by loading CdS quantum dots which can extend its spectral response to the visible region.Platelike WO3·H2O films were prepapred by a facile hydrothermal reaction of RF sputtered W films on the fluorine-doped tin oxide (FTO) glass. The platelike films changed to monclinic WO3and became transparent after annealing at450℃. The annealed film with a thickness of ca.1.5μm was grown vertically on WO3compact layer. The square-shaped plates exhibited an edge length in the range of800nm up to1.2μm and a thickness of50-80nm. The hydrothermal temperature、 reaction time and HNO3concentration have great effects on the morphology and photoelectrochemical propertiy of the films. Optimal reaction conditions for experiments are as follows,1.5M for concentration of HNO3,120℃for hydrothermal temperature,3h for reaction time. The platelike WO3film exhibited a photocurrent density of1.95mA/cm2at1.2V (vs Ag/AgCl sat.)To improve its corrosion resistance to alkaline electrolyte, platelike WO3films was treated with TiCl4. The CdS quantum dots sensitized WO3platelike films were prepapred by chemical bath deposition in alcohol solution. The CdS quantum dots sensitized WO3platelike films exhibited enhanced visible light absorption and photoelectrochemical propertiy compared to the platelike WO3films modified only by TiCl4. The photocurrent density of sensitized films is0.95mA/cm2at-0.1V (vs Ag/AgClsat.)... |
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