利用改进的Hummers方法经冷冻干燥制备氧化石墨（GO），以尿素为还原剂和掺氮剂，二甲基亚砜为溶剂，通过改变微波功率合成掺氮石墨烯。利用FT-IR、XRD、SEM、EDS、Raman、XPS、AFM对样品形貌结构进行表征分析，通过循环伏安、交流阻抗、恒流充放电对样品进行电化学测试。结果表明，在微波功率600 W下得到的掺氮石墨烯，其掺氮量最高，达到7.64%，厚度为0.96 nm，片层为微米-纳米结构，在0.5 A/g电流密度下的比电容达到185 F/g。

The graphite oxide (GO) is prepared through freeze drying by the modified Hummers method.The nitrogen-doped graphene is synthesized by changing the microwave power with urea as nitrogen source and reducing agent,and dimethyl sulfoxide as solvent.The morphology and structure of the as-produced graphene samples are characterized by FT-IR,XRD,SEM,EDS,Raman,XPS and AFM.The electrochemical properties of samples are tested by cyclic voltammetry,AC impedance,and constant current charge and discharge.The results show that the nitrogen-doped graphene obtained at a microwave power of 600 W has the highest nitrogen content of 7.56(wt)%,a thickness of 1.2 nm,a lamellar with the micrometer-nanostructure and a specific capacitance of 185 F·g^-1 at 0.5A·g^-1 current density.