Realizing efficient solar evaporation and rapid lithium sorption by the halloysite nanotubes-based hydrogel

Solar-powered water treatment technology is gaining increasing importance as one solution to ameliorate water resource deficits. This study presents a novel approach of synergistically combining interface solar vaporization technology with low-cost sorption techniques to better enable resource recovery in the water treatment process. After preparation of a halloysite nanotube-based hydrogel, it was subjected to 1 sun illumination. The prepared hydrogel demonstrated an evaporation rate and evaporation efficiency of 2.97 kg/m2·h and 93.2%, respectively, with ideal salt and stain resistance. Under the synergistic effect of halloysite nanotubes (HNTs), the hydrogel efficiently sorbed Li+ at a rate and maximum capacity of 84.15% and 168.3 mg/g, respectively during the solar vaporization process. This study also discussed the main interactions between Li+ and hydrogel sorbents. The results of this study providing a novel and promising approach for concurrent water treatment and Li+ extraction.