Pt-co3 o4 superstructures by one-pot reduction/precipitation in bicontinuous microemulsion for electrocatalytic oxygen evolution reaction Academic Article in Scopus uri icon

abstract

  • © MDPI AG. All rights reserved.Bicontinuous microemulsions (BCME) were used to synthesize hierarchical superstructures (HSs) of Pt-Co3 O4 by reduction/precipitation. BCMEs possess water and oil nanochannels, and therefore, both hydrophilic and lipophilic precursors can be used. Thus, PtAq-CoAq, PtAq-CoOi, PtOi-CoAq and PtOi-CoOi were prepared (where Aq and Oi stand for the precursor present in aqueous or oily phase, respectively). The characterization of the Pt-Co3 O4-HS confirmed the formation of metallic Pt and Co3 O4 whose composition and morphology are controlled by the initial pH and precursor combination, determining the presence of the reducing/precipitant species in the reaction media. The electrocatalytic activity of the Pt-Co3 O4-HSs for oxygen evolution reaction (OER) was investigated using linear sweep voltammetry in 0.1 M KOH and compared with Pt-HS. The lowest onset overpotentials for Pt-Co3 O4-Hs were achieved with PtOi-CoOi (1.46 V vs. RHE), while the lowest overpotential at a current density of 10 mA cm¿2 (¿10 ) was obtained for the PtAq-CoAq (381 mV). Tafel slopes were 102, 89, 157 and 92 mV dec¿1, for PtAq-CoAq, PtAq-CoOi, PtOi-CoAq and PtOi-CoOi, respectively. The Pt-Co3 O4-HSs showed a better performance than Pt-HS. Our work shows that the properties and performance of metal¿metal oxide HSs obtained in BCMEs depend on the phases in which the precursors are present.

publication date

  • November 1, 2020