The fabrication of advanced graphene‐based electrodes is currently an open research topic because of their potential in a broad range of applications, such as in light‐emitting diodes, field‐effect transistors, solar cells, supercapacitors, batteries, electrochemical energy storage, and sensors, which can be traced back to their remarkable electronic, mechanical, optical, and thermal properties. Herein, the fabrication and characterization of metal‐free few layer graphene‐based composite electrodes for oxygen reduction reaction (ORR) applications is reported. Electrodes’ characterization and performance are assessed using Raman spectroscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The electrocatalytic activity for ORR is elucidated by determination of the reaction onset potential at different pH values. The best formulation shows cathodic peak current density up to −469 μA cm⁻², accompanied by the lowest potential peak separation of 0.17 V and the lowest charge transfer resistance of 1657 Ω cm⁻², which is almost five times lower if compared with the composite electrode without graphene. The results suggest that similar nanocomposites electrodes might be potentially exploited in life processes such as biological respiration, and in energy converting systems such as fuel cells or microbial fuel cells.

中文翻译：

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基于几层石墨烯纳米片的氧还原反应应用无金属复合电极的制备与表征

目前，基于石墨烯的高级电极的制造是一个开放的研究课题，因为它们在广泛的应用中具有潜力，例如在发光二极管，场效应晶体管，太阳能电池，超级电容器，电池，电化学储能以及传感器，可以追溯到其卓越的电子，机械，光学和热学特性。本文报道了用于氧还原反应（ORR）的无金属少层石墨烯基复合电极的制备和表征。电极的表征和性能使用拉曼光谱，循环伏安法和电化学阻抗谱进行评估。通过确定在不同pH值下的反应开始电位，可以阐明ORR的电催化活性。^-2，伴随着最低的电位峰间距为0.17 V和最低的电荷转移电阻为1657Ωcm ^-2，与不带石墨烯的复合电极相比，几乎低了五倍。结果表明，类似的纳米复合材料电极可能在生命过程（例如生物呼吸）和能量转换系统（例如燃料电池或微生物燃料电池）中得到开发。