SYTHESIS, COMPOSITION AND PHOTOELECTROCHEMICAL ACTIVITY OF ZINC– COBALT OXIDE COATINGS

Abstract

The aim of the current work was to obtain photoactive Zn-O-Co coatings on stainless steel and to determine their composition and photoelectrochemical activity. This work is relevant to developing photocatalytic methods for the oxidative destruction of organic pollutants and decomposition of water. Zinc-cobalt oxide coatings on AISI 304 type stainless steel were prepared by electrochemical deposition in potentiostatic conditions. The synthesis was carried out using Zn(CH₃COO)₂, Co(CH₃COO)₂ and KNO3 aqueous solutions. The obtained Zn-O-Co coatings were characterized by atomic absorption spectroscopy (AAS), Fourier-transform infrared (FTIR), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF) and photovoltametry. The experimental results show that the most uniform and mechanically stable coatings are obtained at -1.15 V, the deposition time being 3 min ant the synthesis temperature 70 °C. Depending on the electrolyte bath composition, the Zn : Co ratio in as-deposited coatings varies in the range of 5.00-0.28. Based on the photocurrent measurements, the incident photon-to-current efficiency (IPCE) was estimated to be highly dependent on coating composition.

http://dx.doi.org/10.5755/j01.ct.57.1-2.549