The development and optimization of concentrated solar power plants (CSP) plants, which are considered promising sources of renewable and clean energy, have attracted significant attention. Recently, efforts to improve the efficiency of these plants have focused on increasing their operational temperature. However, this approach presents challenges, particularly regarding the corrosion of metallic components due to the higher temperatures of the molten salts used for energy storage. One potential solution to enhance the thermophysical properties of molten salts and mitigate corrosion is the incorporation of nanomaterials as additives. To This study investigates the effect of multilayer Ti₃C₂T<inf>x</inf> MXenes at concentrations of 0.5, 1, 2, and 3 wt.-% on the thermal properties of nanofluids consisting of solar salt, thus aiming at enhancing the thermophysical performance for high-temperature thermal energy storage applications. This pioneering research explores how the concentration of MXene affects the specific heat capacity (C<inf>p</inf>), melting temperature (T<inf>m</inf>), and decomposition temperature (T<inf>d</inf>) of the nanofluids. Our results verified that adding MXenes to solar salt helps to enhance its thermal properties, particularly the decomposition temperature (T<inf>d</inf>) to 609.8 °C (compared to 586.2 °C for pure solar salt) and specific heat capacity (C<inf>p</inf>), enabling better heat storage. These enhancements are attributed to structural and chemical effects induced by multilayer Ti₃C₂T<inf>x</inf>, as supported by experimental analyses (TGA, DSC, SEM, Raman spectroscopy, and XRD) and computational simulations. This demonstrates the potential of Ti₃C₂T<inf>x</inf> for advancing high-temperature thermal energy storage systems in CSP plants. © 2025 Elsevier B.V., All rights reserved.