INFLUENCE OF ELEMENT OXYGEN ON THE ABSORPTIVITY AND EMISSIVITY OF 434-L STAINLESS-STEEL SOLAR SELECTIVE ABSORBER FOR SOLAR THERMAL CONVERSION APPLICATION

In this study, stainless-steel selective solar absorber was synthesized via a simple hydrothermal treatment method. The aim is to investigate the influence of element oxygen (O) on the solar absorptivity and thermal emissivity for solar collector applications. The Energy-Dispersive X-ray Spectroscopy (EDS), Ultraviolet-Visible-Near infrared Spectroscopy (UV-Vis-NIR), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the elemental component, absorptance (α), and emittance (ε) of the synthesized samples. EDS measurement and analysis confirmed that the as-received 343-L stainless-steel (SS) is composed of the elements: C, F, Si, Cr, and Fe while the Oxidized SS is composed of similar elements with the exception of F and Si. The additional elements contained in Oxidized SS includes O and Na respectively. UV-Vis-NIR Spectroscopy shows that the as-received SS exhibits highest reflectance of about 50 % in UV-vis-NIR (0.25 – 2.50 µm) while the Oxidized SS exhibits the lowest reflectance of about 4 % in the same wavelength regions. Similarly, FT-IR Spectroscopy revealed that the as-received SS exhibits highest reflectance of about 85 % in the mid-far IR wavelength region while the Oxidized SS sample exhibits lowest reflectance of about 70 % in the same wavelength zone. The absorptance (α) and emittance (ε) analysis of the as-received SS is 0.35 and 0.19 while the corresponding value of the Oxidized SS is 0.921 and 0.34 respectively. These results confirmed that the element ‘O’ have a significant influence on the ‘α’ and ‘ε’ values of the Oxidized SS.