Development of high-efficiency Ti3C2-MXene/SiO2 composite nanofluids for solar thermal conversion: Synergistic effect of forward scattering and volumetric absorption

Solar energy, recognized for its abundant and clean attributes, is a burgeoning renewable resource. Nanofluid photothermal conversion technology with volume absorption properties has been rapidly developed in recent years. This research optimized the performance of Ti 3 C 2 (MXene) nanofluid in solar photothermal conversion by integrating SiO 2 nanoparticles to form a composite nanofluid. The stability, thermal conductivity, and photothermal properties of the Ti 3 C 2 /SiO 2 nanofluids were comprehensively evaluated. The nanofluids demonstrated high stability, as evidenced by Zeta potentials all above 40 mV. Furthermore, the thermal conductivity of the nanofluids escalated with an increase in SiO 2 content. Specifically, the thermal conductivities of the composite nanofluids experienced an approximate 9 % enhancement when the temperature was elevated by 25 °C. The composite nanofluid had better light absorption because of SiO 2 nanoparticles’ forward scattering ability. The most efficient mixture (Ti 3 C 2 : 40 ppm and SiO 2 : 1000 ppm) reached a 67.35 % photothermal conversion efficiency, which is 5 % higher than the Ti 3 C 2 nanofluid alone at the same concentration. Rather than solely enhancing light absorption, this study provides a new pathway to improve the photothermal conversion efficiency of nanofluids by strengthening scattering. This contributes to enriching the theoretical and practical understanding of nanofluids in the field of photothermal conversion, offering scientific evidence and technical support.