Preparation and Characterization of Nanosized Hematite Colloids Using Green Vitriol as Ferrum Source

Figure 7

The XPS spectra of Fe 2p (a) and O 1s (b) of the as-prepared nanosized α-Fe₂O₃. (a) 723.9 eV and 710.0 eV are the binding energies of Fe 2p_1/2 and Fe 2p_3/2, respectively, and 715.7 eV is the satellite peak; (b) the binding energy 529.9 eV is assigned to surface oxygen with lower electron density, described as surface oxygen species O⁻, and higher than one of the lattice O²⁻, 528.1 eV.

(a)

(b)