Figure 5.

The TEM of (a), Fe₃O₄ (22 nm), (b), Fe₃O₄@SiO₂ (core 60 nm, shell 10 nm) and (c), Fe₃O₄@SiO₂@chitosan (total 105 nm, thickness of chitosan 12 nm) and (d), the SEM of Fe₃O₄@SiO₂@chitosan, and (e), the EDS of sample-chitosan. The composite NPs having spherical core–shell and chain-like structure with a good dispersion are effective adsorbents for aquosus Hg²⁺, Pb²⁺, and Cu²⁺. Reprinted from Ref. [79]. Copyright 2016 American Scientific Publishers.