Electrochemical, spectroscopic and optical studies of the copper oxide selective surface prepared by anodic passivation: Application to heliothermal conversion

Abstract The formation of a selective surface of copper oxide by anodic passivation of copper in 1M NaOH has been studied. Cyclic voltammetry and chronopotentiometry, X-ray diffraction, ESCA and Auger spectroscopy, scanning electron microscopy and optical measurements (absorptance and emittance) related to the experimental preparation of the selective surfaces are presented. The most efficient surfaces for heliothermal conversion are obtained with high current density (2 mA cm −2 ) and temperatures in the 50–57°C range. They are essentially constituted of CuO.