使用大氣電漿製程製作石墨烯/奈米碳管奈米複合材料超級電容

Abstract

本研究利用氮氣大氣噴射電壓處理石墨烯、石墨烯/奈米碳管、奈米碳管電極，並應用於超級電容之製作。利用網印法將石墨烯/奈米碳管製作於電極上後，再利用大氣噴射電漿進行熱處理。由光放射頻譜發現氮氣與碳產生劇烈反應；由電子微探儀和X射線光電子能譜儀發現大氣噴射電漿對碳纖維布的氮摻雜作用；由掃描式電子顯微鏡發現對於石墨烯和奈米碳管之最佳製程時間為15 ~ 30 秒。在超級電容應用方面，大氣電漿處理能有效提昇超級電容之電容值，石墨烯超級電容、石墨烯/奈米碳管超級電容、奈米碳管超級電容在掃描速率2 mV/s 循環伏安法下比電容值為82.5、67.3、60.6 F/g。改良為凝膠態電解液後，增加材料負載(materials loading)下的石墨烯超級電容在掃描速率2 mV/s 循環伏安法下有著 145.3 F/g (10.6 mF/cm2)的表現。

This study investigates the reduced graphene oxides (rGOs), carbon nanotubes (CNTs), and CNT/rGO composites sintered by nitrogen dc-pulse atmospheric-pressure plasma jet (APPJ). The sintered nanoporous materials are used for the electrodes of supercapacitors. The rGO/CNTs was coated on the electrode by screen printing and sintered by APPJ. Optical emission spectroscopy results indicate that the vigorous interaction between the nitrogen APPJ and the carbon. The nitrogen doping effect on carbon fiber cloth was observed by EPMA and XPS. The optimum process time for rGO and CNTs is 15 to 30 s. APPJ sintering significantly improves the charge storage and capacitance value. Evaluated by cyclic voltammetry under a potential scan rate of 2 mV/s, the best achieved specific capacitances are 82.5, 67.3, and 60.6 F/g for 15-s APPJ-sintered pure rGO, 15-s APPJ-sintered rGO/CNT and 30-s APPJ-sintered pure CNT supercapacitors, respectively. The specific capacitance is 145.3 F/g (areal capacitance = 10.6 mF/cm2) with a H2SO4/polyvinyl alcohol (PVA) gel electrolyte pure rGO supercapacitors.