The development of non-noble metal carbon electrocatalysts is of great significance to the development of fuel cell, metal–air battery and water-splitting technology. In this work, a highly active Co–N-doped graphene bifunctional electrocatalyst (Co–N–C/rGO) was prepared by a very mild and simple method. With graphene oxide as the substrate, gluconic acid acts as a dispersion of cobalt and an additional carbon source, while urea acts as a nitrogen source and anchoring cobalt. Co–N–C/rGO showed excellent catalytic performance for the ORR, which even exceeded that of commercial Pt/C. In 0.1 M KOH, the onset potential and half-wave potential of Co–N–C/rGO are 1.04 V and 864 mV, respectively, which are higher than those of most of the similar carbon materials reported. Compared with Pt/C, the half wave potential loss is reduced by 35 mV, and it still shows obvious four-electron transfer characteristics and higher Tafel slope performance. Co–N–C/rGO-based primary liquid ZABs display a higher galvanostatic discharge capacity as well as higher power density. Moreover, we improved the traditional PVA electrolyte, and designed and prepared a PVA + PEO + GO electrolyte with better performance. The flexible ZABs fabricated using air electrodes containing Co–N–C/rGO and this solid electrolyte demonstrate good performance, with a high open circuit potential (1.49 V) and large peak power density (57 mW cm⁻²). In addition, the good HER catalytic performance of Co–N–C/rGO is characterized by a low Tafel slope of 42 mV dec⁻¹ and an overpotential of 220 mV at a current density of 10 mA cm⁻².

中文翻译：

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高活性Co-N掺杂石墨烯可作为高效的双功能电催化剂（ORR / HER），用于柔性全固态锌-空气电池

非贵金属碳电催化剂的开发对燃料电池，金属空气电池和水分解技术的发展具有重要意义。在这项工作中，通过非常温和且简单的方法制备了高活性的Co-N掺杂石墨烯双功能电催化剂（Co-N-C / rGO）。以氧化石墨烯为底物时，葡萄糖酸充当钴和其他碳源的分散体，而尿素充当氮源和锚固钴。Co–N–C / rGO对ORR表现出优异的催化性能，甚至超过了商用Pt / C。在0.1 M KOH中，Co–N–C / rGO的起始电势和半波电势分别为1.04 V和864 mV，高于报道的大多数类似碳材料的电势。与Pt / C相比，半波电势损失降低了35 mV，而且仍然显示出明显的四电子转移特性和更高的塔菲尔斜率性能。基于Co–N–C / rGO的初级液体ZAB表现出更高的恒电流放电能力以及更高的功率密度。此外，我们对传统的PVA电解液进行了改进，设计并制备了性能更好的PVA + PEO + GO电解液。使用包含Co–N–C / rGO的空气电极和这种固体电解质制造的柔性ZAB具有良好的性能，具有高的开路电势（1.49 V）和大的峰值功率密度（57 mW cm 设计并制备了性能更好的PVA + PEO + GO电解液。使用包含Co–N–C / rGO的空气电极和这种固体电解质制造的柔性ZAB具有良好的性能，具有高的开路电势（1.49 V）和大的峰值功率密度（57 mW cm 设计并制备了性能更好的PVA + PEO + GO电解液。使用包含Co–N–C / rGO的空气电极和这种固体电解质制成的柔性ZAB具有良好的性能，具有高的开路电势（1.49 V）和大的峰值功率密度（57 mW cm）^-2）。另外，Co–N–C / rGO具有良好的HER催化性能，其特征是：在10 mA cm ^-2的电流密度下，Tafel斜率低，为42 mV dec ^-1，过电位为220 mV。