以氧化石墨烯为前驱液,采用水热技术在碱性环境下合成出水溶性较好的石墨烯。采用扫描电子显微镜技术（SEM）和X射线粉末衍射（XRD）对石墨烯的结构形貌做了表征。采用循环伏安法等电化学测试技术考察了石墨烯电极对抗坏血酸的电催化性能。实验结果表明,抗坏血酸在该石墨烯电极上的电化学活性显著提高。在pH=6.99条件下,峰电流响应最大。在优化条件下,抗坏血酸的响应电流和其响应浓度（1×10^-4~1×10^-3 mol/L）呈较好的线性关系,线性回归方程为I（A）=14 927.87c（mmol/L）+41.19,线性相关系数R²=0.998 9。该检测方法用于维生素C药片的实际测定,与标准测定方法相比,具有较高的准确度。

Hydrothermal method was used to prepare graphene with good water-solubility selecting graphene oxide as precur-sor in alkaline environment.Scanning electron microscopy（SEM） and powder X-ray diffraction（XRD） were used to character-ize the structure and morphology of as-prepared graphene.The electrocatalytic property of graphene electrode on ascorbic acid was investigated using various elecrochemical testing techniques.The results showed that the electrocatalytic oxidation activity of ascorbic acid on this graphene electrode was significantly enhanced.The response peak current of ascorbic acid was optimum under the condition of pH =6.99.Under the optimized experimental conditions,the response current of ascorbic acid was linear well with its corresponding concentration in the range of 1×10^-4~1×10^-3 mol/L.The linear regression equation was I（A）=14 927.87c（mmol/L）+41.19 and the linear correlation coefficient R²=0.998 9.Compared with the standard method,this method applied to the determination of vitamin C tablets has higher accuracy.