近年來由於能源危機意識提高，能量儲存成為一個新興領域同時也是節能措施中極為重要的一環，超級電容具有功率密度高、充放電速度快，安全性高的特點，但目前的超級電容之能量密度不及鋰離子電池，限制了超級電容的應用。因此提升超級電容的儲能密度是目前研究的主要方向。
本研究探討石墨烯之合成與利用聚苯乙烯微球(polystyrene spheres)作為模板，製作多孔石墨烯電極並應用於超級電容器上。研究中利用熱還原法還原氧化石墨烯，在還原過程中同時將聚苯乙烯微球移除製備多孔石墨烯電極，希望藉由多孔結構增加比表面積以提升電容值。
實驗中選用兩種尺寸的PS球作為模板，藉由添加不同比例的PS球，來觀察所產生的孔洞大小和數量，以及對電容值的影響，根據實驗結果最好的比例為70 wt% 0.2 μm的PS 球，此比例所製備的多孔石墨烯電極，具有84.5 F/g的電容值。
為了提升材料電性，在製備過程中加入多巴胺，經由800 ℃熱處理後，氮原子成功摻雜多孔石墨烯，形成氮摻雜多孔石墨烯，片電阻下降2個數量級，並使電容值上升至168.8 F/g。

Recently, owing to increase in awareness of energy crisis, energy storage has become a new field as well as an important issue for energy saving. The supercapacitor has attracting great attention owing to its high power density, short charging time and safety during operation. However, the energy density of the supercapacitors is still lower than that of lithium-ion battery, as a result, restricting the application of supercapacitors. In this regards, enhancing energy density of the supercapacitors is the main theme of current research.
In this work, graphene was synthesized and polystyrene (PS) spheres were used as templates to fabricated graphene-based porous electrodes for supercapacitors. The feature of the processing for porous graphene electrodes is that the thermal reduction method to reduce graphene oxide and to remove PS spheres can be completed simultaneously. Owing to the presence of porous structure in electrodes, it is expected that the electrodes possess higher specific surface area and specific capacitance.
Regarding the use of PS spheres, we chose two sizes of PS spheres as templates and studied the influences of PS size and amount on the structure and capacity of the porous graphene electrodes. According to the results, the electrode containing 70 wt% PS spheres with a size of 0.2 μm possess a capacitance of 84.5 F/g.
In order to enhance the electrical conductivity of the electrodes dopamine was added during the process and the electrodes were subsequently subjected to heat treatment at 800 ℃. As a result, nitrogen atoms were successful doped into porous graphene and formed nitrogen-doped porous graphene, which could effectively reduce two orders of magnitude in the sheet resistance and achieved a better capacitance of 168.8 F/g.

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