Optical, stability and energy performance of water-based MXene nanofluids in hybrid PV/thermal solar systems

Solar thermal collectors have been recognized as promising devices for solar energy harvesting. The absorbing properties of the working fluid are crucial because they can significantly influence the efficiency of the solar thermal collectors. The performance of photovoltaic-thermal (PV/T) systems can be optimized by applying nanofluids as working fluids. MXene is a newly developed 2-D nanomaterial that has proven excellent potential in electrical applications with a lack of research in the thermal and optical applications. The present work extensively studied the optical potential of the water/MXene nanofluids with respect to the variation of MXene concentrations (0.0005-0.05 wt%) and types of surfactant (CTAB or SDBS) used in a hybrid PV/T system. The relationship between the investigated parameters was evaluated through an experimental correlation. The evaluation of the nanofluids in term of the transmittance was conducted through the Rayleigh method. The MXene concentrations and the types of the surfactant play predominant role in the transmittance, absorbance and dispersion stability of the water/MXene nanofluids. The corresponding effects due to these factors become the most noticeable in the wavelengths of 300-1350 nm. Low concentration of the MXene and shorter path lengths lead to higher transmittance. The application of the low concentration of water/MXene nanofluids as the optical filtration in a hybrid PV/T system yields a higher performance compared to a conventional PV/T system. Therefore, this research work provides novelty value in understanding the impacts of using water/MXene nanofluid in the hybrid PV/T solar collectors to harness additional energy.