A novel non-selective coating material for solar thermal potential application formed by reaction between sol-gel titania and copper manganese spinel

A method for preparing a novel bixbyite non-selective coating for solar thermal conversion is described. The coating is formed by a thermal reaction between a titania sol-gel precursor with a copper manganese spinel to form a new material, Cu0.44Ti0.44Mn0.84Fe0 28O3, with a bixbyite structure. The effect of temperature and ratio between the two components on the formation of the bixbyite layer (deposited on Inconel by spray-coating) was studied. The absorptance of the films (AM 1.5; 335-2500 nm) with a thickness of 10 +/- 2 mu m after annealing at 2 h at 650 degrees C and 750 degrees C was 97.4% and 94.7%, respectively. This synthesis represents a novel approach in which the final solar thermal coating is formed as a continuous and uniform layer which combines both the absorber and the ceramic binder. The developed material shows promising results for future applications as absorber in solar thermal energy conversion. (C) 2013 Elsevier B.V. All rights reserved.