製備金奈米線及聚苯胺之核殼結構於石墨箔基材做為電極於擬電容之特性探討

於本研究中，我們藉由電化學沉積法在石墨箔表面進行一維金奈米線合成，並以循環伏安法進行聚苯胺電化學聚合，在金奈米線表層形成核殼結構。其中我們探討循環伏安法中的兩個參數: 合成掃描圈數以及速率，對於聚苯胺表層厚度與重量的變化，以及表面形貌對於電容表現的影響。由掃描式電子顯微鏡以及電化學聚合聚苯胺的重量分析，可以得知掃描圈數越多，在金奈米線表層所形成的聚苯胺重量越多，厚度增加。而掃描速率越低，會影響反應中苯胺單體的擴散速率，導致形成的聚苯胺重量越多，厚度增加。我們在硫酸鈉中以循環伏安法進行不同合成條件下的電容值分析，除了觀察到聚苯胺的氧化還原反應，表現出擬電容的特徵；也觀察到在固定10mV/s的掃速下，聚苯胺厚度5 nm，重量0.06 mg的條件下可以得到最高的比電容值，隨著厚度與重量增加而下降。根據其他聚苯胺核殼結構於擬電容的文獻，5-10 nm厚的聚苯胺層可以達到最低的內電阻以及最低電荷傳輸造成的電阻值。在合成掃描速率200 mV/s, 以及合成掃描圈數5的結構下，在比電容的分析中可於2 mV/s的掃描速率中得到最佳比電阻值1010 F/g，與其他PANI構成之電容材料相比擁有表現良好的比電容值。

關鍵字

金奈米線；聚苯胺；電化學；超級電容

並列摘要

In this thesis, the AuNWs/ PANI was fabricated on graphite substrate through electrochemical deposition and electrochemical polymerization. The influence of polymerization cycle and sweeping rate to AuNWs/PANI composites morphology and capacitance is investigated. By using scanning electrode microscope (SEM) and the weight loading of PANI, it could be concluded that the AuNWs/PANI structure has more PANI weight and thicker layer when increasing the polymerization cycle. In addition, the weight and thickness of PANI increased with slower polymerization sweeping rate due to the influence of diffusion of aniline in the electrolyte. The capacitance performance of electrodes under different synthesis condition was investigated using cyclic voltammetry in three-electrode system, 1 M Na2SO4. It was observed that the AuNWs/PANI composite electrode exhibited a highest specific capacitance of 1010 F/g under a scan rate 2 mV/s, with PANI thickness of 5 nm and weight 0.06 mg, and the specific capacitance decreased with higher PANI thickness and weight. This could be explained by the thickness of PANI had an ideal thickness of 5-10 nm to reduce the internal resistance and shorten the diffusion length of electrons.