Fig. 3: Water sorption capacity of BHNC.

a, Multi-step water sorption processes of BHNC at different temperatures, including solid–gas chemisorption from LiCl to LiCl·H2O at low RH, liquid–gas deliquescence from LiCl·H2O to saturated LiCl solution at moderate RH and liquid–gas absorption from saturated LiCl solution to dilute LiCl solution at high RH. b, Thermogravimetric analysis and differential scanning calorimetry (TG-DSC) curves of BHNC under 30 °C with RH range from 15% to 60% for water sorption (15%, 30%, 60%) and 90 °C at 4,200 Pa for water desorption. c, Comparison of water uptake between our BHNC and reported state-of-the-art sorbents for SAWH10,16,39,40,41,42,43,44. d, Comparison of water sorption kinetics between our BHNC and reported state-of-the-art salt-based composites16,18,19,32,45,46,47 in arid climates under 20–40% RH; the conversion ratio can be calculated as q/qmax (details in Supplementary Table 2).