Optical Properties and Photothermal Conversion Characterization of TiN Nanofluids with Different Base Fluids

Optimal optical absorption properties are imperative for the utilization of nanofluids in solar energy applications. Excellent optical absorption facilitates the augmentation of solar energy utilization efficiency. The base fluid contributes significantly to the optical properties of the nanofluid. However, the effect of base fluid on the nanofluid optical properties has yet to be explored. This work investigates the effect of three base fluids, deionized water, ethylene glycol, and 1,2-propanediol, on the optical absorption properties of titanium nitride (TiN) nanofluids. The results show differences in the optical properties of the TiN nanofluids prepared for different sonication times. With the absence of surfactant addition, the stability of TiN nanofluids based on ethylene glycol-based and 1,2-Propanediol-based surpasses that of deionized water-based TiN nanofluids. However, in comparison to ethylene glycol-based and 1,2-Propanediol-based, deionized water-based TiN nanofluids exhibit commendable light absorption capacity. Finally, the photothermal conversion efficiency is calculated for different base fluids. The photothermal conversion efficiency of the deionized water-based TiN nanofluid is 50.82%, which is 13.91% and 15.98% higher than that of the ethylene glycol-based and 1,2-propanediol-based TiN nanofluids under the same conditions, respectively. Thus, deionized water-based TiN shows excellent optical absorption properties, essential for enhanced solar energy thermal utilization. This work will help guide the application of TiN nanofluids.