{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T05:04:48Z","timestamp":1769922288909,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2020,3,28]],"date-time":"2020-03-28T00:00:00Z","timestamp":1585353600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-16422"],"award-info":[{"award-number":["POCI-01-0145-FEDER-16422"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/QUI-ELT\/28299\/2017"],"award-info":[{"award-number":["PTDC\/QUI-ELT\/28299\/2017"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","doi-asserted-by":"publisher","award":["UID\/QUI\/50006\/2013-POCI\/01\/0145\/FEDER\/007265"],"award-info":[{"award-number":["UID\/QUI\/50006\/2013-POCI\/01\/0145\/FEDER\/007265"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>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\u2013GF and Mn\/S3N2\u2013GF). 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\u2013GF composite exhibits the best ORR performance with an onset potential of 0.91 V vs. RHE, a diffusion-limiting current density of \u22124.50 mA cm\u22122 and selectivity for the direct four-electron pathway, matching the results obtained for commercial Pt\/C. Moreover, both Co\/S3N2\u2013GF and Mn\/S3N2\u2013GF showed excellent tolerance to methanol poisoning and good stability.<\/jats:p>","DOI":"10.3390\/ma13071562","type":"journal-article","created":{"date-parts":[[2020,4,1]],"date-time":"2020-04-01T03:44:13Z","timestamp":1585712653000},"page":"1562","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["Metal Oxide (Co3O4 and Mn3O4) Impregnation into S, N-doped Graphene for Oxygen Reduction Reaction (ORR)"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2198-6978","authenticated-orcid":false,"given":"Penny","family":"Mathumba","sequence":"first","affiliation":[{"name":"Department of Chemistry, Faculty of Science, University of the Western Cape (UWC), Cape Town, Bellville 7535, South Africa"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5263-2737","authenticated-orcid":false,"given":"Diana M.","family":"Fernandes","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, 4160-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3567-9469","authenticated-orcid":false,"given":"Renata","family":"Matos","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, 4160-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6102-0433","authenticated-orcid":false,"given":"Emmanuel I.","family":"Iwuoha","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Faculty of Science, University of the Western Cape (UWC), Cape Town, Bellville 7535, South Africa"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1753-8678","authenticated-orcid":false,"given":"Cristina","family":"Freire","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, 4160-007 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2020,3,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.rser.2016.09.135","article-title":"The recent progress and future of oxygen reduction reaction catalysis: A review","volume":"69","author":"Stacy","year":"2017","journal-title":"Renew. 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