ELECTROPLATING OF SELECTIVE SURFACES FOR CONCENTRATING SOLAR COLLECTORS

摘要

Method of manufacturing a spectrally selective surface. The method comprises cleaning an outside of a tubular substrate, e.g. by sonicating in acetone, polishing the cleaned outside, and depositing a Co—Cr coating on the polished outside, i.e. the tubular substrate's outside. The Co—Cr coating comprises Co(II) compounds and Cr(III) compounds but no Cr(VI) compounds. By applying a DES electrolyte Cr(III)-ions may be solved in the electrolyte such that a receiver tube arranged in the electrolyte may become coated with a selective Co—Cr coating from Cr(III)-ions, where the optical characteristics regarding absorptance and emittance for the resulting receiver tube are comparable or surpasses traditional black chrome. Thereby use of harmful hexavalent chrome could be avoided, which may achieve more healthy and environmental friendly conditions. Particularly, no harmful Cr(VI)-ions or rest substances comprising them will contaminate ambient air or need to be handled or disposed.