Coatings of Fe3O4 Nanoparticles as Selective Solar Absorber

Cost-effective and pollution-free green chemical method has been employed for synthesizing Fe 3 O 4 nanoparticles which can be used as a solar absorbent and characterized further for their structural, optical and morphological properties using X-ray diffraction and UV-VIS-IR spectrophotometry and transmission electron microscopy techniques, respectively.Presence of Fe 2+ and Fe 3+ in nanoparticles is confirmed from the X-ray photoelectron spectroscopy analysis.The nanometric grain-size allows deposition of thin films, and the resulting coatings onto copper substrate show a relatively low thermal emittance in a range of 0.05-0.10.The solar absorptance values are between 0.76 and 0.85, which can provide an acceptable selectivity.Attempt is also made to find influence of the thickness effect on the selectivity having 15.2 as best value for one layer coating.