Chitosan/WS2 nanosheets co-assembled aerogels with anisotropic micro-channels for efficient Pb(II) adsorption

Building aerogels-based adsorbents with high adsorption capacity, selectivity, and structure designing through green and simple ways was urgent issue for the removal of Pb2+ from contaminated water. In this study, for the first time, chitosan was applied as assistant agents for the liquid-phase exfoliation of WS2 nanosheets, and the composite aerogels (CS/WS2) with oriented microchannel structures were obtained via directional co-assembly processes. Owing to the potential H-bond between CS and WS2, as well as the sulfur-rich surfaces, CS/WS2 aerogels exhibited promising Pb2+ adsorption performance (similar to 275.9 mg/g) than many other chitosan-based adsorbents. Besides, the adsorption of Pb2+ by CS/WS2 aerogels were also rapid (reached an equilibrium at similar to 120 min), selective (similar to 54% of maximal Pb2+ uptake), and sustainable (maintained similar to 90% of the maximal uptake). This work paved a simple and green way to construct WS2 nanosheets-based aerogels with delicate micro-structures and favorable Pb2+ adsorption performances.