Cu(I) Modification during γ-Fe₂O₃ Nanoparticles Synthesis and Subsequent Characterization

Table 2

Binding energies (eV) from X-ray photoelectron spectroscopy (XPS) spectra for samples (1), (2), and (3).

(a) For samples (1) and (2)

	O 1s		Fe 2p3/2	Cl 2p3/2	Cu 2p3/2
Sample (1)	529.79 (P1);	532.39 (P2)	711.39	198.59	932.09
Sample (2)	529.29 (P1);	532.09 (P2)	711.09	198.79	931.99
Fe2O3	529.6		710.7
CuFeO2	?		?		932.6
FeCl3			711.3	199.0
H2O		532.8

(b) For sample (3)

	O 1s		Fe 2p3/2	Cl 2p3/2	Cu 2p3/2	Cu 2p1/2
Sample (3)	530.09 (P1);	532.49 (P2)	711.19	198.59 (P1)	932.59 (P0)	952.38 (P0′)
Fe2O3	529.6		710.7
CuFeO2	?		?		932.6	Δ
FeCl3			711.3	199.0
H2O		532.8
	Cl 2p3/2	Cl 2p1/2	Cu 2p3/2	STA	Cu 2p1/2	STA
Sample (3)	198.59 (P1)	200.09 (P2)	934.59 (P1)	943.50 (P2)	954.49 (P3)	962.50 (P4)
Cu(OH)Cl	Δ	Δ	Δ	Δ	Δ	Δ
CuCl2	199.1	200.7	935.7	943.2	955.3	964.0
				945.6

Note: standard data for Fe₂O₃, CuFeO₂, FeCl₃, and H₂O from the NIST X-ray Photoelectron Spectroscopy Database at http://www.nist.gov, in which no O 1s, Fe 2p_3/2, and Cu 2p_1/2 data for CuFeO₂ and no Cu(OH)Cl data were provided. Standard data for CuCl₂ from [18].
The binding energy of both O 1s and Fe 2p_3/2 for CuFe₂O could not be determined in the present investigation.