SYNTHESIS, STRUCTURE AND PHOTOELECTROCHEMICAL ACTIVITY OF MIXED COPPER-COBALT OXIDE COATINGS

Abstract

The aim of the current work was to obtain photoactive copper–cobalt oxide coatings on AISI 304 type stainless steel substrate. This work is relevant to the search of new photocatalysts suitable for water photosplitting. Mixed copper–cobalt oxide coatings were synthesized by heating for 3 h at 550 °C the mixtures of copper acetate hydrate Cu(CH₃COO)₂∙H₂O and cobalt acetate tetrahydrate Co(CH₃COO)₂∙4H₂O. The obtained coatings were characterized by X–ray diffraction (XRD), Fourier transform infrared (FT-IR), thermogravimetric–differential scanning microscopy (TG–DSC) and photovoltammetry. The experimental results revealed that mixed copper–cobalt oxide coatings are predominantly composed of spinel-type CuCo₂O₄ phase. The average crystallite size of CuCo₂O₄ particles was calculated to be in the range of 65–76 nm. The prepared coatings show a p-type semiconducting behavior. The value of photogenerated current depends on the molar ratio Cu:Co in the coatings. Unfortunately, photoelectrochemical measurements showed that these coatings are relatively unstable under UV irradiation in aqueous solutions.

DOI: http://dx.doi.org/10.5755/j01.ct.60.2.1803