Characterization of a Novel Coating Process to Darken Sand Particles

The use of solid particles in Concentrated Solar Power (CSP) plants can enhance energy conversion efficiency by elevating the working temperature. For this reason, many researchers are exploring various materials such as silica sand and SiC, among others, and methods to enhance the optical properties while cost is reduced. In this context, this study proposes a novel fabrication method based on the Mn2+ diffusion to darken silica sand particles and, therefore, enhancing their absorptivity. Colorimetry analysis reveals that the obtained particles color closely resembles that of the reference material SiC, while morphology analysis, Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD) confirm an effective fabrication method.