Table 2. Structural parameters obtained from the fitting of EXAFS spectra.

Sample	Coordination shell	Coordination number, CN	Interatomic distance, R (Å)	Debye−Waller factor (σ2) (Å2)	R-factor k range R range
CeO2-bulk	O	8†	2.34 ± 0.02	0.0097	0.044
	Ce	12†	3.84 ± 0.01	0.005	4–13
	O	24†	4.39 ± 0.08	0.014	1.5–4.2
CeO2-NPs-15 nm	O	8†	2.33 ± 0.02	0.009	0.032
	Ce	10.3 ± 0.8	3.84 ± 0.01	0.005†	4–13
	O	10.5 ± 15.1	4.43 ± 0.07	0.014†	1.5–4.2
CeO2-NPs-6.3 nm	O	8†	2.33 ± 0.01	0.0009	0.022
	Ce	8.4 ± 0.6	3.83 ± 0.01	0.005†	4–13
					1.5–4.2
CeO2-NPs-5.7 nm	O	8†	2.33 ± 0.02	0.0116	0.052
	Ce	8.0 ± 0.8	3.84 ± 0.01	0.005†	4–13
					1.5–4.2
CeO2-NPs-2.9 nm	O	8†	2.34 ± 0.02	0.0125	0.053
	Ce	5.1 ± 0.5	3.84 ± 0.01	0.005†	4–13
					1.5–4.2
CeO2-NPs-2.5 nm	O	8†	2.34 ± 0.02	0.0161	0.068
	Ce	3.8 ± 0.5	3.84 ± 0.01	0.005†	4–11
					1.5–4.0
CeO2-NPs-2.2 nm	O	8†	2.35 ± 0.02	0.0171	0.175
	Ce	2.6 ± 0.6	3.87 ± 0.02	0.005†	4–11
					1.5–4.0
PuO2-bulk	O	8†	2.33 ± 0.01	0.0061	0.016
	Pu	12†	3.82 ± 0.01	0.004†	3–14
	O	24†	4.39 ± 0.02	0.010	1.3–4.2
PuO2-NPs-3.2 nm	O	8†	2.32 ± 0.02	0.012	0.080
	Pu	4.7 ± 0.7	3.83 ± 0.01	0.004†	3–12
					1.3–4.0
PuO2-NPs-2.2 nm	O	8†	2.31 ± 0.01	0.011	0.028
	Pu	3.3 ± 0.4	3.81 ± 0.01	0.004†	3–12
					1.3–4.0
PuO2-NPs-2.0 nm	O	8†	2.31 ± 0.02	0.012	0.16
	Pu	1.7 ± 1.1	3.80 ± 0.03	0.004†	3–12
					1.3–4.0

^†Parameters were fixed.