| Summary: | 碩士 === 國立東華大學 === 光電工程學系 === 103 === The Hydrogen Energy has been regarded as the key energy capable of replacing fossil fuel, and the development of Hydrogen energy technology is therefore attracting attention worldwide; especially the photocatalytic hydrogen production technology is becoming one of the important research issues due to its low energy consumption and low pollution. This dissertation mainly aims to develop some narrow-band-gap (2.19 eV) as well as recyclable NiFe2O4 soft magnetic photocatalytic material, conduct certain photocatalytic reforming Hydrogen production research using the first-generation biofuel to determine the correlations between the process parameters and the crystal’s microscopic structure, surfaces, magnetic features, optic energy band features and Hydrogen production efficiency, and probe into how the use of different first-generation biofuel and light factors affect the chemical composition of the solutions produced during the transformation of saccharomycete into ethanol and its effects upon Hydrogen production efficiency.
The first stage of the research mainly conducted microscopic structure analysis and magnetic feature analysis upon the processed NiFe2O4 photocatalytic material. The XRD result indicated that the designated NiFe2O4 photocatalytic material was polycrystalline structure, whose temperature increased from 1000oC to 1200oC when undergoing thermal treatment; the size of the diffractive surface (311) crystalline grain increased from 39 nm to 45 nm, the preferred orientation of the crystal face was [311], the angle of the main diffractive crest value was 35.6o. Furthermore, the result of the magnetic hysteresis loop analysis showed that the highest saturated magnetic flux density, 77 emu/g, occurred at 1100oC whereas the result of the photo-luminescence spectrometry analysis showed that once the sample had undergone high-temperature thermal treatment, the life cycle of the charge carriers were easily shortened, electrons and electron holes were also easily compounded and therefore resulted in the decrease of its photocatalytic activity. In short, the most optimized process parameter is the sample processed at 1100oC.
The second stage of the research mainly used visible light to assist saccharomycete in transforming different types of starch to produce bio-ethanol. The research showed that after being cultivated on Petri dishes for seven days, the saccharomycete cultivated under visible light obviously contained more hyphae. Furthermore, cornstarch was found to contain the highest fermented concentration of bio-ethanol 268 g/L; the bio-ethanol produced by waxy-rice starch could reach 434 g/L if distilled once. Last but not least, this research integrated all the above-mentioned optimized parameters; especially the bio-ethanol in question as the sacrificial reagent (electron hole scavenger) to proceed to the third stage, i.e. using the NiFe2O4 sample processed at 1100oC as the photocatalyst for conducting the light reforming Hydrogen production research within the photobioreactor. The result pointed out that using the bio-ethanol produced by cornstarch as the sacrificial reagent yielded the highest Hydrogen production rate, 6748 µmol/hr.
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