We describe a novel synthesis technique for the production of graphitic carbon functionalized Co3O4 (G/Co3O4), which involves the rapid decomposition of cobalt nitrate in the presence of citric acid. Upon immobilization of the G/Co3O4 upon Screen-Printed macroElectrodes (G/Co3O4-SPEs) the G/Co3O4-SPEs were found to exhibit remarkable electrocatalytic properties towards the Oxygen Reduction Reaction (OER). A detailed investigation has been carried out on the influence that the graphitization of the citric acid has, during the course of preparation of Co3O4, upon the ability of the G/Co3O4 to catalyse the OER within alkaline conditions (1.0 M KOH). The graphitization of citric acid ensures the uniform distribution of Co3O4 and enhanced conductivity with maximal exposure of active sites, which are the key parameters to delivering enhanced electrochemical activity. The G/Co3O4-SPEs exhibits an overpotential of 304 mV (recorded at 10 mA cm−2), a Tafel slope of 110 mV dec−1 and remain stable in its signal output (achievable current density) at varying temperatures (5–50 °C), and after 10 h of chronoamperometry in 1.0 M KOH. The G/Co3O4-SPE's OER activity was found to be superior to that of bulk and nano Co3O4. The results exhibited within this study will enable production of high-performance and environmentally benign electrocatalysts towards the OER for use within water splitting devices.

中文翻译：

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功能化 Co3O4 石墨纳米颗粒：用于析氧反应的高性能电催化剂


我们描述了一种用于生产石墨碳功能化 Co3O4 （G/Co3O4） 的新型合成技术，该技术涉及在柠檬酸存在下硝酸钴的快速分解。将 G/Co3O4 固定在丝网印刷大电极 （G/Co3O4-SPE） 上后，发现 G/Co3O4-SPE 对氧还原反应 （OER） 表现出显著的电催化特性。在制备 Co3O4 的过程中，柠檬酸的石墨化对 G/Co3O4 在碱性条件 （1.0 M KOH） 内催化 OER 的能力的影响进行了详细的调查。柠檬酸的石墨化确保了 Co3O4 的均匀分布和增强的导电性，并最大限度地暴露了活性位点，这是提供增强电化学活性的关键参数。G/Co3O4-SPE 表现出 304 mV 的过电位（在 10 mA cm-2 处记录），110 mV dec-1 的塔菲尔斜率，并在不同温度 （5-50 °C） 下保持其信号输出（可实现的电流密度）稳定，并在 1.0 M KOH 中计时安培 10 小时后。发现 G/Co3O4-SPE 的 OER 活性优于块体和纳米 Co3O4。本研究中展示的结果将使生产高性能且对环境无害的电催化剂成为可能，用于 OER 以用于水分解装置。