| Summary: | 碩士 === 臺灣大學 === 化學工程學研究所 === 95 === InTaO4 is a photocatalyst used for water splitting. In the past, InTaO4 was prepared using the solid-state fusion method. By this method, catalysts are calcinated above 1100℃ and the component of InTaO4 is not uniformed. In this study, InTaO4 photocatalysts are prepared from In(NO3)3 and Ta(OC4H9)5 precursors using the thermal hydrolysis and sol-gel methods. This method solves the problems of high calcination temperature and non-uniform distribution, via mixing in the liquid phase. The prepared sol can be coated on quartz plates as well as optical fibers. From SEM analysis, the catalyst surface consists of spherical particles with nano-pores. Particle sizes are about 20nm and film thickness is ranges in 40~45nm. The calcinated catalyst powder was used in the liquid-phase photoreduction of CO2 to examine its photocatalytic activity. GC-analysis shows that methanol is the major products. XRD analysis indicates that at 1100℃, InTaO4 crystalline is formed, however at 850℃~950℃ the crystallization is incompleted. From UV-Vis spectroscoy, the photocatalyst starts to absorb light at 500nm. Experiments show that the 1.0wt%-NiO/InTaO4 has a higher photoactivity. The amount of methanol productions by catalysts calcined at various temperatures are as follows: 16.1μmole/g-cat at 850℃, 23.7μmole/g-cat at 900℃, 27.2μmole/g-cat at 950℃ and 28.0μmole/g-cat at 1100℃ respectively. The catalyst prepared by the solid state reaction method produces 20.5μmole/g-cat of methanol.
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