Electrostatically Assisted Construction Modified MXene-IL-Based Nanofluids for Photothermal Conversion

Solar energy, as renewable energy, has paid extensive attention for solar thermal utilization due to its unique characteristics such as rich resources, easy access, clean, and pollution-free. Among them, solar thermal utilization is the most extensive one. Nanofluid-based direct absorption solar collectors (DASCs), as an important alternative method, can further improve the solar thermal efficiency. Notably, the stability of photothermal conversion materials and flowing media is critical to the performance of DASC. Herein, we first proposed novel Ti₃C₂T_x-IL-based nanofluids by the electrostatic interaction, which consists of functional Ti₃C₂T_x modified with PDA and PEI as a photothermal conversion material and ionic liquid with low viscosity as the flow medium. Ti₃C₂T_x-IL-based nanofluids exhibit excellent cycle stability, wide spectrum, and efficient solar energy absorption performance. Besides, Ti₃C₂T_x-IL-based nanofluids maintain liquid state in a range of −80 to 200 °C, and its viscosity was as low as 0.3 Pa·s at 0 °C. Moreover, the equilibrium temperature of Ti₃C₂T_x@PDA-IL at a very low mass fraction of 0.04% reached 73.9 °C under 1 Sun, indicating an excellent photothermal conversion performance. Furthermore, the application of nanofluids in photosensitive inks has been preliminarily explored, which is expected to play a role in the fields of injectable biomedical materials and photo/electric double-generation thermal and hydrophobic anti ice coatings.