Sulfuric acid is commonly used to electrochemically activate gold electrodes in a variety of electrochemical applications. This work provides the first evaluations of the electrochemical behaviors and a 3D image of an activated screen-printed gold electrode (SPGE, purchased commercially) through electrochemical and imaging analyses. The activated SPGE surface appears rougher than the unactivated SPGE surface when viewed through microtopography images using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Nevertheless, the roughened microscopy structure does not exhibit any substantial changes in roughness factor for the activated SPGE, as indicated by capacitive current analyses. The significant improvement in electrochemical responsiveness of the activated SPGE is mainly attributed to the presence of surface pores created in the microscopic structure as a result of gold oxide layer formation. The presence of surface pores on the activated surface has significantly improved its conductivity by 10-fold. As a result, electron transfer kinetics and mass transports of the activated SPGE are greatly improved. The results presented in this work indicate that the surface of the activated SPGE greatly increased its intrinsic surface pores, and conductivity of the electrode surface and uncovered the electrocatalytic active sites. This significantly improves the activated SPGE's performance in electrochemical applications such as oxygen reduction reaction (ORR). An activated SPGE considerably enhanced limiting current density as well as ∼172 mV versus Ag shifted onset potential to more positive potentials compared to unactivated SPGE.

中文翻译：

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电化学激活丝网印刷金电极的电化学和成像评估


硫酸通常用于在各种电化学应用中对金电极进行电化学活化。这项工作通过电化学和成像分析提供了对电化学行为的首次评估和活化丝网印刷金电极（SPGE，商业购买）的 3D 图像。使用扫描电子显微镜 （SEM） 和原子力显微镜 （AFM） 通过微形貌图像观察时，活化的 SPGE 表面看起来比未活化的 SPGE 表面更粗糙。然而，如电容电流分析所示，粗糙化的显微镜结构在活化的 SPGE 的粗糙度因子上没有表现出任何实质性的变化。活化 SPGE 的电化学响应性的显着改善主要归因于由于氧化金层的形成，在微观结构中产生了表面孔。活化表面上的表面孔隙使其导电性显著提高了 10 倍。因此，活化 SPGE 的电子传递动力学和传质性能得到了极大的改善。这项工作提出的结果表明，活化的 SPGE 表面大大增加了其内禀表面孔隙和电极表面的电导率，并揭示了电催化活性位点。这显著提高了活化 SPGE 在氧还原反应 （ORR） 等电化学应用中的性能。与未活化的 SPGE 相比，活化的 SPGE 显著提高了极限电流密度以及 ∼172 mV 与 Ag 相比，起始电位转变为更正的电位。