Biogenic Synthesis of Magnetite Nanoparticles Using Leaf Extract of Thymus schimperi and Their Application for Monocomponent Removal of Chromium and Mercury Ions from Aqueous Solution

Figure 6

SEM images of Fe₃O₄ NPs: (a) for uncalcined in (1 : 1), (b) for calcined S11 in (1 : 1), (c) for calcined S12 in (1 : 2), and (d) for calcined S21 in (2 : 1).

(a)

(b)

(c)

(d)