Competitive sorption of Ni and Zn at the aluminum oxide/water interface: an XAFS study

Table 2 EXAFS fitting results of Ni for model compounds and sorption samples (S ²₀ = 0.93)

Sample	Shells	CN	R (Å)	σ² (Å²)	R_f	ΔE₀ (ev)
Ni(NO₃)₂ aq.	Ni–O	6.0^a	2.06	0.005	0.0010	− 0.90
Ni–Al LDH	Ni–O	5.8	2.06	0.006		2.00
	Ni–Ni	3.5	3.07	0.007	0.0005
	Ni–Al	0.8	3.06	0.007
Ni–Zn–Al LTH	Ni–O	6.3	2.06	0.007		2.86
	Ni–Ni/Zn	3.5	3.07	0.008	0.0010
	Ni–Al	1.3	3.06	0.008
Ni–Al Alox	Ni–O	5.3	2.06	0.005		2.56
	Ni–Ni	3.4	3.06	0.008	0.0014
	Ni–Al	1.9	3.05	0.008
Ni–Zn–Al Alox	Ni–O	5.5	2.06	0.005		2.57
	Ni–Ni/Zn	4.1	3.07	0.008	0.0010
	Ni–Al	1.5	3.06	0.008

Estimated errors for the first shell are ± 20% for coordination number, ± 0.01 Å for bond distance and ± 0.001 Å² for Debye–Waller factors, and for second shell ± 40% for coordination numbers, ± 0.04 Å for bond distances and ± 0.005 Å² for Debye–Waller factors
CN coordination number and were determined by the fit, R the interatomic distance in Å, σ² the Debye–Waller factor in Å², R_f the absolute misfit between data and theory, ΔE₀ the energy shift in eV
^aFixed value

ISSN: 1467-4866