Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 94 === To efficiently split water for hydrogen generation relies heavily on the development and design of light-driven photocatalysts including finding new catalysts and improve the old catalysts. The latter can be improved by decreasing the particle size, increasing the surface area , loading metal oxide and doping heteroatom. Suitable modification of the surface sites might increase the photocatalytic activity of the catalyst.
In this study, AgTaO3 catalysts were prepared by solid-state reaction method and sol-gel method and were further modified through loading NiO and doping La. The performances of the prepared catalysts for water splitting under UV light irradiation were investigated. The effects of different preparation parameters on the photocatalytic activities of the catalysts were also studied. The catalysts were characterized by using powder X-ray diffractometer (XRD), scanning electron spectroscope (SEM), ultravillet-visible spectrophotometer (UV-Vis). The photocatalytic reaction was carried out in a Pyrex reactor with 400 W high pressure mercury lamp as UV light source.
All of the AgTaO3 absorb UV light catalysts prepared by solid-state reaction and sol-gel methods were fully crystallized to form Perovskite-type phases after being calcinated at a temperature about 850℃. SEM shows that the particles sizes of catalysts prepared by the sol-gel method are far smaller than those prepared by the solid-state reaction method.
For water splitting, AgTa O3 catalysts prepared by sol-gel method showed higher activities than those prepared by solid-state reaction method. AgTaO3 catalysts prepared by sol-gel method and calcined to 850℃ had the highest activity( Average rate of hydrogen generation = 4.47 μmol/hr‧gcat.). When this catalyst was further loaded with NiO, a loading of 1 wt % would give the best performance ( Rate of H2 evolution = 9.31 μmol/hr‧gcat. ).
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