| Summary: | 碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 102 === Metal-organic frameworks (MOFs, Ni-terephthalic acid) were synthesized by hydrothermal reaction. MOFs were carbonized at different temperatures (400~900℃) to form mesoporous carbon/Ni composite electrodes. The effects of porous structure and surface area on the capacitive behavior were systematically investigated. X-ray diffraction analysis and transmission electron microscopy revealed that the graphitic layers could be formed. Utilization of the specific surface area analyzer observed specific surface area of carbonized MOFs at different temperatures. Cyclic voltammetry (CV) test was carried out in 1 M KOH electrolyte solution to diagnose the reversibility of the electrodes. Galvanostatic charge and discharge tests were used to evaluate the specific capacitance value and the cycle-life stability of the electrodes. Results showed that at a discharge current density of 1 A g-1, the specific capacitance values of up to 886 F g-1 could be reached for the MOF carbonized at 800C (MOF-800 electrode). Either low or high current density test, the specific capacitance of MOF-800 electrode was much higher than that of other carbonization temperatures. Mainly with high specific surface area and porous structure of the MOF-800 electrode, the diffusion of the electrolyte can effectively enter the interior of the electrode, leading to an increase in the specific capacitance. Sufficient amount of graphitic carbon did not significantly reduce the surface area of electrode, but its conductivity was increased drastically, so that the specific capacitance can be improved effectively.
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