| Summary: | 碩士 === 國立交通大學 === 材料科學與工程學系所 === 104 === The solid oxide fuel cell (SOFC) and proton exchange membrane fuel cell (PEM) with hydrogen as a fuel are presently widely used. The studies on hydrogen production technologies are thus very important now. Among the hydrogen producing technologies, the photoelectrochemical cell (PEC) has a great potential to become the best choice. For PEC electrodes, TiO2 NTs, are useful for water splitting, so we focus on the study of TiO2 NT electrode fabrication.
We employ the anodization method to produce TiO2 NTs, and use doping, and hydrogenation to improve their efficiency. The modified TiO2 NTs have been characterized with SEM, EDS, XPS and XRD. In the last step of our study, we irradiate the samples to measure the efficiency of water splitting with solar simulator.
Based on our analysis, we find that at 300°C hydrogen can diffuse into the TiO2 lattice and generate the Ti-OH bonding to increase the oxygen vacancies, and thus enhances the efficiency of water splitting. In addition, electrochemical reduction TiO2 NTs can also reduce Ti4+ to Ti3+ on the surface to generate oxygen vacancies, and the vacancies can improve the efficiency of water splitting.
We can also improve water splitting efficiency by Ni-doping of TiO2 to catalyze and enhance the TiO2 hydrogenation process with two different methods. First, with the soaking method, samples can achieve 0.452% efficiency for hydrogen production, which is 4.5 times higher than that of untreated TiO2 nanotubes. Second, with the anodization method, the efficiency increases to 0.476%, which is 4.7 times higher than that of untreated TiO2 nanotubes.
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