Figure 3.

FE-SEM and TEM images of the synthesized NSG/Fe₃O₄ composites: (a) FE-SEM images reveal Fe₃O₄ nanoparticles encapsulated in N, S co-doped graphene nanosheets; (b) FE-SEM images; (c) TEM images show that there are many Fe₃O₄ nanoparticles distributed and encapsulated in N, S co-doped graphene nanosheets; (d) high-magnification TEM images showing that Fe₃O₄ nanoparticles are contained in N, S co-doped graphene nanosheets effectively. Reprinted with permission from Ref. [65]. Copyright 2022 Springer Nature Limited.