Photothermal evaporation characteristics of magnetic rGO/Fe2O3 nanofluid droplets

The evaporation kinetics of magnetic nanofluid droplets under solar irradiation is important for their photothermal applications in energy and medicine areas. In this work, magnetic nanofluids were employed to study the evaporation kinetics including mass, temperature, and contact angle under solar irradiation. Compared with deionized water, the evaporation rate of magnetic nanofluid droplets was doubled and increased with the initial mass. At the beginning of evaporation, the evaporation rate reached the maximum value, and the stable evaporation stage was close to the end time. Moreover, the higher the light intensity was, the maximum evaporation rate appeared earlier and the stable evaporation time was shortened. At the same time, the higher the extreme value of the evaporation rate, the faster the rate of decline, and the shorter the evaporation time, when the light intensity was higher than 800 W/m2, the rate does not change significantly. This interfacial evaporation technology of magnetic nanofluid droplets offers great convenience to liquid and droplet handling and may be implemented in a multitude of domains such as bio-sensing, chemistry combination, and solar catalytic fuel production.