Codoping-Induced, Rhombus-Shaped Co3O4 Nanosheets as an Active Electrode Material for Oxygen Evolution
2015 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 7, no 39, 21745-21750 p.Article in journal (Refereed) Published
Nanostructured Co3O4 doped with Zn2+, Ni2+, and both were directly grown on an ITO substrate by an easily available hydrothermal method. The doped Co3O4 showed a unique structural morphology evolution upon controlling the doping elements and the doping ratio of the cations. For the codoped samples, the novel rhombus-shaped Co3O4 nanosheets doped with Zn2+ and Ni2+ (concentration ratio of 1:2) exhibited the optimal electrocatalytic performance. The sample showed a current density of 165 mA cm(-2) at 1.75 V, approximately 1.6 and 4 times higher than that of samples doped with Zn2+ and Ni2+ at a concentration ratio of 1:1 and 1:3. The unique architecture and its corresponding modified physical properties, such as high active-site density created by codoping, large structural porosity, and high roughness, are together responsible to its superior performance. For codoped Co3O4 nanostructures, Zn2+ facilitates the creation of Co cations in their high oxidation state as active centers, while Ni2+ contributed to the new active sites with lower activation energy. The synergistic effect of Zn2+ and Ni2+ doping can explain the improved physicochemical properties of codoped Co3O4 nanostructures.
Place, publisher, year, edition, pages
2015. Vol. 7, no 39, 21745-21750 p.
water splitting, oxygen evolution reaction, electrocatalysis, codoped Co3O4, nanostructures
IdentifiersURN: urn:nbn:se:uu:diva-265820DOI: 10.1021/acsami.5b05149ISI: 000362628900018PubMedID: 26383787OAI: oai:DiVA.org:uu-265820DiVA: diva2:866636