| Summary: | 碩士 === 國立中興大學 === 化學工程學系所 === 102 === Hydrogen is one of the green energy. It is clean and contain high energy (285.8J/mol). The photocatalysis is a potential method to produce hydrogen. In this study, InVO4 was chosen as a photocatalysts to split the water into hydrogen. By controlling the preparation conditions for the synthesis InVO4 to identify the surface structures、crystalline phases and the efficiency for the water splitting.
Hydrothermal method has been used to synthesize InVO4 catalysts. The control parameters of hydrothermal synthesis include In/V ratio of 2:1、1:1、1:2； hydrothermal time of 1hr、2hr、4hr、8hr； pH value of 3、5、7、9 and hydrothermal temperature of 160°C、180°C、200°C、220°C. The InVO4 catalysts were characterized by FE-SEM、TEM、XRD、BET、FT-IR、and GC for analyzed the water splitting efficiency.
When the starting material of In3+ is relatively higher in concentration, the SEM images of crystalline particle size is about 100 nm, but there have In(OH)3 residues present for in XRD and FT-IR analysis. In addition, the crystalline structure of InVO4 could be incomplete when there is only 1hr hydrothermal treatment. There is a better hydrogen production of 102.7μmole/g‧cat when the hydrothermal treatment time increase to 4hr and the ratio of In:V=1:2. The pH value also affects the InVO4 catalysts preparation. In strong acid environment, there is a large amount of by-products (NH4)2V6O16 form. In alkaline environment, however, there is a large amount of residues In(OH)3. As the result, the optimum conditions to synthesis InVO4 are at the ratio of In:V=1:2, pH5 and hydrothermal temperature and treatment time are 200°C for 4hr. The cumulative concentration of hydrogen after 4hr water splitting reaction is 113.9μmole/g‧cat .
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