Simultaneous Photoreduction and Nitrogen Doping of Graphene Oxide for Supercapacitors by Direct Laser Writing

Graphene-based supercapacitors have attracted tremendous attention owing to their outstanding electro-chemical performance. In terms of material, nitrogen(N)-doped graphene(NDG) displays enhanced specific capaci- tance and rate performance compared with bare graphene used as a supercapacitor electrode. However, it still remains a challenge to develop a facile and simple method of NDG in cost-effective manner. Here, we used a simple direct laser writing technique to accomplish the simultaneous photoreduction and N-doping of graphene oxide(GO) using urea as a N source. The N content of the resultant reduced N-doped graphene oxide(NGO) reached a maximum value of 6.37%. All reduced NGO(NRGO)-based supercapacitors exhibited a higher specific capacitance than those based on pure reduced GO(RGO). Interestingly, the electrochemical performance of NRGO-based supercapacitors varied with different contents of N species. Therefore, we can control the properties of the obtained NRGOs by adjusting the doping ratios, an important step in developing effective graphene-based energy storage devices.