电泳沉积制备氧化石墨烯-银电极及其氧还原催化性能

通过在1-甲基-2-吡咯烷酮（NMP）中超声剥离氧化石墨制备出稳定的氧化石墨烯（GO）分散液，添加AgNO₃使氧化石墨烯吸附Ag+而带正电荷。采用电泳沉积法使GO沉积到阴极的玻璃碳电极上，Ag+被电化学还原为单质银，均匀的分散在GO片层当中。通过AFM、SEM、Raman、XRD及元素面扫分析对制备电极的形貌、结构进行表征。在碱性环境中进行氧还原测试，结果表明GO+Ag电极的氧还原起始电位较玻璃碳电极最大正移228mV，还原电流密度最大为7.564mA·cm^-2，是玻璃碳电极的3.4倍。通过不同转速下的线性扫描曲线绘制Koutechy-Levich图，计算氧还原反应的电子转移数为3.3。

Preparation of Graphene Oxide-silver Electrodes by Electrophoretic Deposition and Its Catalytic Performance for Oxygen Reduction

Graphene oxide (GO) nanosheets were exfoliated from Graphite Oxide in 1-Methyl-2-pyrrolidinone (NMP), and silver nitrate was added, then GO was charged by the silver ions. GO nanosheets were deposited on glassy carbon (GC) electrode by electrophoretic deposition (EPD), the silver ions were electrochemically reduced to silver particles, uniformly dispersed in the GO nanosheets. The modified electrodes morphology and microstructure were characterized by AFM, SEM, Raman, XRD and elemental mapping. The catalytic behavior during oxygen reduction on the modified electrodes was studied in alkaline medium. This research revealed that the onset potential of oxygen reduction on the GO+Ag electrode shifted to the positive direction by 228 mV compared with the GC electrode; the reduction current density on the GO+Ag electrode was found to be 7.564 mA·cm^-2, which is 3.4 times as that of the GC electrode. Using the LSV curves recorded at different rotation rates to construct Koutechy-Levich plots, the electron numbers is 3.3.