Degradation of Methylene Blue Using Hydrothermally Synthesized α-Manganese Oxide Nanostructures as a Heterogeneous Fenton Catalyst

Figure 2

SEM images of MnNSs prepared at 160°C at different times (a) H1 (3 hrs), (b) H2 (6 hrs), (c) H3 (12 hrs), and (d) H4 (24 hrs).

(a)

(b)

(c)

(d)