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Characterization and degradation testing of nickel pigmented anodic alumina solar selective absorber films produced by alternate and reverse periodic plating technique

Nickel pigmented anodic alumina solar selective absorber films have been prepared using alternate and reverse periodic plating technique. The films show favorable characteristics, high absorptance (α = 0.97), low emissivity (ϵ = 0.16), for the use as solar selective absorber materials. The effect of the alternate and reverse periodic plating parameters on the optical and films microstructural properties has been studied. Optical and structural properties of the films are investigated using X-ray diffraction, TEM, SEM, EDS, UV/VIS/near IR. These investigations reveal that the nickel particles in alumina pores are spherical with average crystals size ranged from approximately 150–300 Å. The optical characteristics of the films with the preparation conditions are compared. The stability of the films to high temperatures and humidity has been tested. The results from these tests show that the reverse periodic plated films are more sensitive to degradation process mainly nickel oxidation.