Metal oxide (Co3O4 and Mn3O4) impregnation into S, N-doped graphene for oxygen reduction reaction (ORR)
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Date
2020
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
To address aggravating environmental and energy problems, active, efficient, low-cost, and robust electrocatalysts (ECs) are actively pursued as substitutes for the current noble metal ECs. Therefore, in this study, we report the preparation of graphene flakes (GF) doped with S and N using 2-5-dimercapto-1,3,4-thiadiazole (S3N2) as precursor followed by the immobilization of cobalt spinel oxide (Co3O4) or manganese spinel oxide (Mn3O4) nanoparticles through a one-step co-precipitation procedure (Co/S3N2-GF and Mn/S3N2-GF). Characterization by different physicochemical techniques (Fourier Transform Infrared (FTIR), Raman spectroscopy, Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) of both composites shows the preservation of the metal oxide spinel structure and further confirms the successful preparation of the envisaged electrocatalysts. Co/S3N2-GF composite exhibits the best ORR performance with an onset potential of 0.91 V vs. RHE, a diffusion-limiting current density of-4.50 mA cm-2 and selectivity for the direct four-electron pathway, matching the results obtained for commercial Pt/C. Moreover, both Co/S3N2-GF and Mn/S3N2-GF showed excellent tolerance to methanol poisoning and good stability.
Description
Keywords
Carbon materia, Heteroatom doping, Metal oxides, Oxygen reduction
Citation
Mathumba, P. et al. (2020). Metal oxide (Co3O4 and Mn3O4) impregnation into S, N-doped graphene for oxygen reduction reaction (ORR). Materials ,13(7),1562