Preparation and characterization of carbon/nickel oxide nanocomposite coatings for solar absorber applications

► We presented a sol-gel synthesis process of C/NiO nanocomposites, and studied the effect of process parameters on structural and optical properties. ► Spectroscopic measurements have shown that the absorption edge shifts to the higher wavelength with increase in heating temperature due to an increase in carbon content in the material. ► The present study demonstrates the potential of nanocomposite surfaces as solar thermal conversion materials.