{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T12:33:00Z","timestamp":1775737980690,"version":"3.50.1"},"reference-count":80,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2024,12,23]],"date-time":"2024-12-23T00:00:00Z","timestamp":1734912000000},"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 (FCT\/MCTES)","doi-asserted-by":"publisher","award":["EXPL\/BII-BIO\/0436\/2021"],"award-info":[{"award-number":["EXPL\/BII-BIO\/0436\/2021"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Catalysts"],"abstract":"<jats:p>The development of sustainable and high-performance oxygen reduction reaction (ORR) electrocatalysts is fundamental to fuel cell implementation. Non-precious transition metal oxides present interesting electrocatalytic behavior, and their incorporation into N-doped carbon supports leads to excellent ORR performance. Herein, we prepared a shrimp shell-derived biochar (CC), which was doped with nitrogen via a ball milling approach (N-CC), and then used as support for Co3O4 nanoparticles growth (N-CC@Co3O4). Co3O4 loading was optimized using three different amounts of cobalt precursor: 1.56, 2.33 and 3.11 mmol in N-CC@Co3O4_1, N-CC@Co3O4_2 and N-CC@Co3O4_3, respectively. Interestingly, all prepared electrocatalysts, including the initial biochar CC, presented electrocatalytic activity towards ORR. Both N-doping and the introduction of Co3O4 NPs had a significant positive effect on ORR performance. Meanwhile, the three composites showed distinct ORR behavior, demonstrating that it is possible to tune their electrocatalytic performance by changing the Co3O4 loading. Overall, N-CC@Co3O4_2 achieved the most promising ORR results, displaying an Eonset of 0.84 V vs. RHE, jL of \u22123.45 mA cm\u22122 and excellent selectivity for the 4-electron reduction (n = 3.50), besides good long-term stability. These results were explained by a combination of high content of pyridinic-N and graphitic-N, high ratio of pyridinic-N\/graphitic-N, and optimized Co3O4 loading interacting synergistically with the porous N-CC support.<\/jats:p>","DOI":"10.3390\/catal14120951","type":"journal-article","created":{"date-parts":[[2024,12,24]],"date-time":"2024-12-24T09:48:58Z","timestamp":1735033738000},"page":"951","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["In Situ Synthesis of Co3O4 Nanoparticles on N-Doped Biochar as High-Performance Oxygen Reduction Reaction Electrocatalysts"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3567-9469","authenticated-orcid":false,"given":"Renata","family":"Matos","sequence":"first","affiliation":[{"name":"REQUIMTE\/LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"}]},{"given":"Jorge V.","family":"Manuel","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"}]},{"given":"Ant\u00f3nio J. S.","family":"Fernandes","sequence":"additional","affiliation":[{"name":"Instituto de Nanoestruturas, Nanomodela\u00e7\u00e3o e Nanofabrica\u00e7\u00e3o (I3N), Departamento de F\u00edsica, Universidade de Aveiro, Campus Universit\u00e1rio de Santiago, 3810-193 Aveiro, Portugal"}]},{"given":"Victor K.","family":"Abdelkader-Fern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Departamento de Qu\u00edmica Inorg\u00e1nica, Facultad de Ciencias, Universidad de Granada, 18071 Granada, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1176-9064","authenticated-orcid":false,"given":"Andreia F.","family":"Peixoto","sequence":"additional","affiliation":[{"name":"REQUIMTE\/LAQV, Departamento de Qu\u00edmica e Bioqu\u00edmica, Faculdade de Ci\u00eancias, Universidade do Porto, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"}]},{"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, Rua do Campo Alegre s\/n, 4169-007 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,12,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1155\/2024\/7271748","article-title":"A Recent Comprehensive Review of Fuel Cells: History, Types, and Applications","volume":"2024","author":"Qasem","year":"2024","journal-title":"Int. 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