石墨烯负载纳米银的制备及其对H2O2的电化学检测

采用改进的Hummers法制备了氧化石墨烯（GO），然后以水合肼作为还原剂，并控制反应的pH=10来制备还原氧化石墨烯（RGO）。采用化学还原法，以石墨烯为载体，以乙酰丙酮银为前体，以硼氢化锂四氢呋喃溶液为还原剂将银离子还原，制备了石墨烯负载纳米银复合材料。通过X 射线粉末衍射（XRD）、傅里叶变换红外光谱（FTIR）和透射电子显微镜（TEM）等表征方法证明了石墨烯上负载的银纳米颗粒结晶良好、尺寸均一、分布均匀，其中银纳米颗粒直径约为8nm。通过循环伏安和计时电流技术对石墨烯负载纳米银复合材料进行电化学测试，结果表明，石墨烯负载纳米银复合材料对过氧化氢的还原具有良好的电催化活性。以此复合纳米结构构建的过氧化氢传感器测试过氧化氢浓度的线性范围为0.1～62.3mmol/L（R=0.990），检出限为0.017mmol/L（S/N=3），响应时间小于2s。

Preparation of graphene-supported nano-silver and its electrochemical detection of H2O2

Graphene oxide (GO) was prepared by the modified Hummers method. The reduced oxidized graphene (RGO) was prepared by using hydrazine hydrate as a reducing agent and controlling the pH of the reaction to 10. The graphene-loaded nano-silver composites were prepared by hydrothermal synthesis using graphene as the support, silver acetylacetonate as the precursor and lithium borohydride tetrahydrofuran as the reducing agent. X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and other characterization methods demonstrated that the silver nanoparticles supported on graphene had good crystallinity, uniform size and even distribution. The average diameter of the silver nanoparticles was about 8nm. Electrochemical tests of the graphene-loaded nano-silver composites by cyclic voltammetry and chronoamperometry showed that the graphene-loaded nano-silver composites had good electrocatalytic activity for the reduction of hydrogen peroxide. The linear range of hydrogen peroxide concentration measured by the hydrogen peroxide sensor constructed from the composite nanostructure was 0.1—62.3mmol/L (R=0.990) with the detection limit of 0.017mmol/L (S/N=3) and the response time of less than 2s.