Rapid-Diffusion Water Channels in Lithium Chloride and Carbon Nanotube-Modified MOF-801 for Enhanced Solar Water Harvesting

In atmospheric water harvesting technology, selecting the appropriate adsorbent and constructing the device are crucial. However, most of the adsorbents have some problems, such as weak adsorption capacity and difficult desorption. Hygroscopic salts are one of the effective ways to enhance the adsorption capacity. Based on this, this study successfully prepared an efficient composite adsorbent by modifying MOF-801 with LiCl and carbon nanotubes to improve its adsorption and desorption capabilities. Through comparative studies, we found that the addition of hygroscopic salts had a significant impact on the performance of the MOF-801 adsorbent. Notably, the composite adsorbent exhibits excellent water absorption at low relative humidity (RH = 20%, 25 °C), with a water uptake as high as 0.49 g g^–1, which is four times that of MOF-801. Meanwhile, most of absorbed water from the composite aerogel can be rapidly released with 3 h under 1 sun irradiation due to the photothermal effects of CNT. The adsorbent not only shows rapid kinetics in the adsorption–desorption cycle but also maintains stable performance over multiple cycles.