In Situ Fabrication of Defective CoNx Single Clusters on Reduced Graphene Oxide Sheets with Excellent Electrocatalytic Activity for Oxygen Reduction

4 years ago

In Situ Fabrication of Defective CoNx Single Clusters on Reduced Graphene Oxide Sheets with Excellent Electrocatalytic Activity for Oxygen Reduction

Shuanghua He, Xiaojuan Wang, Minli Tan, Huiqiong Wu, Juan Xiang, Yi Zhang, Peng Xue, Lunzhao Yi, Rujuan Shen, Jing Ma, Ting He, Hui Xue

A facile one-step strategy for anchoring defective CoN_x single clusters on partly reduced graphene oxide (RGO) is constructed to significantly improve the catalytic performance of non-noble metal complexes toward oxygen reduction reaction (ORR). Sequent loading with trace amounts of metal-free porphyrin and Co²⁺ in RGO can dramatically enhance both the half-wave potential and the peak current density. Intriguingly, the RGO/P/2Co single cluster exhibits the best ORR catalytic performance with the half-wave potential of 0.834 V, extremely approaching that of commercial Pt/C (0.836 V). This half-wave potential surpasses most of the reported half-wave potentials of RGO supported non-noble metal ORR catalysts through low-temperature synthesis. Furthermore, the as-prepared RGO/P/2Co delivers a peak current density of 1.3 times higher than that of Pt/C at the same loading, together with a high mass activity of 2.76 A mg_Co^–1. During the durability test, a cathodic current loss less than 10% is recorded after 8000 continuous potential cycles. Insights into this successful example will be conducive to the development of elegant routes for constructing metal nitrogen (MN)-based ORR catalysts with high efficiency, outstanding stability, and excellent selectivity.

Publisher URL: http://dx.doi.org/10.1021/acsami.7b04667

DOI: 10.1021/acsami.7b04667