Figure 13.

Fe₃O₄ nanoparticles, α-Fe₂O₃ hollow spheres, and the two-step electrode design. (a, b) TEM images of Fe₃O₄ nanoparticles encapsulated within carbon shells anchoring on RGO sheets. Adapted from [66] and reproduced with the permission of the Royal Society of Chemistry. (c) SEM and (d) TEM images of α-Fe₂O₃ hollow spheres with sheet-like subunits. Adapted from [67] and reproduced with the permission of the American Chemical Society. (e) Illustration of a two-step electrode design consisting the electrochemically assisted template growth of Cu nanorods onto a current collector followed by the electrochemical plating of Fe₃O₄.