Figure 4.

Scanning electron microscopic (SEM) images of MC-Fe-S2 in different magnifications ((a)–(c); (a) scale bar: 200 $\mathsf{\mu }\mathrm{m}$, (b) scale bar: 10 $\mathsf{\mu }\mathrm{m}$, (c) scale bar 1 $\mathsf{\mu }\mathrm{m}$). Energy dispersive X-ray image of MC-Fe-S2 for C-K (d), S-K (e) and Fe-K (f), all scale bars 200 $\mathsf{\mu }\mathrm{m}$.