Investigation of the stability of the boron-doped diamond support for Co3O4-based oxygen evolution reaction catalysts synthesized through in situ autocombustion method

Abstract

• The In Situ Autocombustion allows easy preparation of oxide–carbon composites for OER. • Co 3 O 4 nanoparticles in composites are smaller and less agglomerate than bulk one. • The Co 3 O 4 -BDD composite is a competitive electrocatalyst for the alkaline OER. • Higher stability of the BDD compared either to Vulcan or Sibunit conventional carbons. • BDD is a promising support for alkaline or anion exchange membrane electrolysis cells. In this work we studied the anodic stability of nanostructured Boron-Doped Diamond (BDD) in view of its eventual utilisation as support for metal oxide–carbon composites prepared by the In Situ Autocombustion (ISAC) method. The anodic behaviour of the BDD was investigated by the rotating ring-disc electrode (RRDE) method in 1 M NaOH electrolyte to determine its corrosion current and compare the latter with that of the commercial Vulcan XC-72 carbon from Cabot and Sibunit pyrolytic carbon, the latter known for its high stability against electrochemical corrosion. The BDD has proven to be significantly more stable than either the Sibunit or the Vulcan carbon. The Co 3 O 4 -BDD and Co 3 O 4 -Sibunit composites prepared by the ISAC method were then tested as catalysts of the oxygen evolution reaction (OER). The Co 3 O 4 -BDD composites appear to be competitive electrocatalysts for the OER in alkaline medium, showing activity comparable to the literature and much higher support stability towards oxidation. Further research is required to decrease the size of Co 3 O 4 spinel nanoparticles and improve their distribution over the BDD support and hence increase the mass-specific OER activity of the BDD-based ISAC composites.