Supplementary information for
Easily prepared and stable functionalized magnetic ordered
mesoporous silica for efficient uranium extraction
WenLu Guo1,2, ChangMing Nie1*, Lin Wang2，ZiJie Li2
Lin Zhu1,2, LiuZheng Zhu2, ZhenTai Zhu3, WeiQun Shi2 & LiYong Yuan2*
1
School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China.
Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049,
China.
3
State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China
2
SI-1 Sorption experiments
The sorption experiments were carried out using the batch method. The initial concentrations of U(VI)
varied from 5–200 mg L−1. The pH of solution was adjusted by adding negligible volumes of sodium
hydroxide solution or diluted nitric acid solution. In a typical experiment, 4 mg adsorbent was added
into either 10 ml multi-ion or 10 mL U(VI) solution test solution in polytetrafluoroethylene-lined screw
cap glass tubes (50 ml). The polytetrafluoroethylene-lined screw cap glass tubes were shock in Shaking
Water Bath for specified time (t, min) at 20°C, and then the solid phase was magnetically separated
from the solution for 360 min at 20°C, the two phases were separated by an external magnet. The
control experiment was performed at the same time using the identical U(VI) solution without
adsorbent. Before the determination, solutions filtering by needle type filter, and diluted 50 times for
the concentration analysis. The concentrations of U(VI) in the solution were determined by UV–Visible
spectrometry and the multi-ion were determined by inductively coupled plasma optical emission
spectrometer (ICP-OES). All values were measured in duplicate with the uncertainty within 5%.
SI-2 Analytical techniques
The morphologies, sizes of the samples were examined with a field emission scanning electron
microscopy (SEM, Hitachi S-4800). Power X-ray diffraction (PXRD) patterns of the materials were
obtained on a Bruker D8-Advance X-ray Diffractometer with a Cu Kα radiation (λ=1.5406 Å).
Thermogravimetric curve were recorded on a thermal gravimetric analyzer (TGA, TA Instruments,
Q500) from 50-800 °C by a heating rate of 5 °C min-1 under air flow for the study of functionalized
content of the magnetic materials. Data of fourier transform infrared (FT-IR) spectra of the prepared
samples were record on a Bruker Tensor 27 spectrometer with a potassium bromide pellet method. The
N2 adsorption experiments were measured at a liquid nitrogen temperature (77K) using a micromeritics
ASAP
2020
HD88
instrument.
The
specific
surface
area
was
calculated
by
the
Brunauer–Emmett–Teller (BET) method with prior degassing under vacuum at 120 °C. Zeta Potentials
were obtained by Malvern Zetasizer Naw ZS90. For the concentration analysis of U(VI), the
UV–Visible spectrometry with arsenazo-III as the chromogenic agent was used at an
absorption wavelength of 656 nm. Inductively coupled plasma optical emission spectrometer
(ICP-OES, HORIBA, JY 2000-2) was used to analyze the initial and equilibrium concentration of the
ions in the multi-ion solution.
SI-3 Synthesis of MMSN and MMSN10N
FeSO4
FeCl3
TEOS CTAB
NaOH 80℃
APS 120℃
-NH2
550℃
6h
SI-4 Effect of pH
200
MMSN10N
MMSN
MMSN20N
qe mg/g
150
100
50
0
-50
2
3
4
5
6
pH
Fig. S1 Effect of pH in MMSN, MMSN10N and MMSN20N msorbent/Vsolution=0.4 mg mL-1, [U]initial
=100 mg L-1
SI-5 Sorption kinetic study
In order to study the sorption kinetic process, we had use the simplified kinetic model, the
pseudo-first-order model[1] and pseudo-second-order model[2] to fit U(VI) sorption kinetics:
The pseudo-first-order equation:
ln(qe  qt )  ln qe  k1t
(S1)
The pseudo-second-order equation:
t
1
t
=
+
2
qt k2 qe qe
(S2)
Where k1，k2 is the sorption rate constant (min−1 for first-order sorption, g mg−1 min−1 for second-order
sorption); t is the contacting time (min); qe is the sorption amount at equilibrium time; qt is the sorption
amount at time t. Constants and correlation coefficients were shown in Table S1. It can be seen that the
experimental values qe are close to the theoretical qe (cal) values calculated from the
pseudo-second-order model. Furthermore, the correlation coefficient
(R2>0.99)
suggesting that the
sorption follows pseudo-second-order model process which means the ordinary type of exchange
processes and controlled mainly by diffusion[3] .
2.5
MMSN10N
Pseudo-second-order
t/qt
2.0
1.5
1.0
0.5
a
0.0
-50
0
50 100 150 200 250 300 350 400
Time/min
5
MMSN10N
Pseudo-first-order
4
ln(qe-qt)
3
2
1
0
b
-50
0
50 100 150 200 250 300 350 400
Time(min)
Fig. S2 (a) Shows linearity between t/qt versus t, an indication of good matching of the experimental
kinetics data with pseudo-second-order model; (b) shows linearity between ln(qe-qt) versus t, an
indication of not good enough matching of the experimental kinetics data with pseudo-first-order
model
Table S1 Kinetics model constants and correlation coefficients for the removal of U(VI)
pseudo-first-order
pseudo-second-order
qe(mg g−1)
k1 (min−1)
R2
qe (mg g−1)
k2 (g mg−1 min−1)
R2
58
1.29×10-2
0.92
155.5
7.4×10-4
>0.99
It is known that the sorption process on porous adsorbents is generally described by four stages: bulk
diffusion, film diffusion, intraparticle diffusion and sorption on the adsorbents surface[4] . Some of
these stages may determine the amount of sorption in the adsorbent and the rate of sorption.
Intraparticle diffusion model has been expressed with the equation given by Weber and Morris[5]:
qt  kid t 1/ 2
(S3)
Where qt is the sorption amount at time t and kid is the intraparticle diffusion constant (mg g−1 h−1). The
plot of qt as a function of t1/2 gives a straight line, from which kid can be acquired.
SI-6 Sorption isotherms study
To verify the sorption type, the batch sorption experiment data were fitted by Langmuir and
Freundlich[6] models respectively. From the linear form of these isotherms model, equations can be
written as follows:
ce
c
1

 e
qe bq0 q0
ln qe  ln k F 
ln ce
n
(S4)
(S5)
where qe is the sorption capacity (mg g-1) at equilibrium time, ce is the equilibrium concentration of
U(VI) ions in solution (mgL-1), q0 is the saturated sorption
capacity (mg g-1), b is an empirical
parameter, kF and n are the Freundlich constants related to the sorption capacity and the sorption
intensity, respectively. As we all know, the Langmuir model is an empirical expression used to describe
homogeneous monolayer sorption, where sorption activation energy is uniform on the adsorbent
surface. The Freundlich model is applicable to a heterogeneous system. Correlation coefficients for the
sorption on MMSN10N calculated from Langmuir and Freundlich are listed in Table S2. It can be seen
that the sorption results agree well with the Langmuir isotherm with the correlation coefficients >0.99.
0.5
a
0.4
ce/qe
0.3
0.2
0.1
MMSN10N
Langmuir-model
0.0
-10
0
10
20
30
40
50
60
70
80
ceq (mg/L)
5.5
b
5.0
lnqe
4.5
4.0
3.5
MMSN10N
3.0
Freundlich-model
2.5
0
1
2
3
4
5
lnce
Fig. S3 (a) Shows linearity between ce/qe versus ceq, an indication of good matching of the experimental
kinetics data with Langmuir model; (b) shows linearity between lnqe versus lnce, an indication of not
good enough matching of the experimental kinetics data with Freundlich model
Table S2 Isotherm model constants and correlation coefficients for the removal of U(VI)
Langmuir
q0 (mg g−1)
179.2
Freundlich
b (L mg−1)
R2
KF (mg g−1)
n
R2
0.5892
0.99
34.9
2.318
66
SI-7
Leached Fe %
10
2h
12h
8
6
4
2
0.0
0.2
0.4
0.6
0.8
HNO3 Concentration M
1.0
Fig.S4 Released Fe by HNO3 solutions
SI-8
Table S3 The desorption of U(VI) from MMSN10N
Desorption
[HNO3]a/mol L-1
0.01
0.05
Efficiency (%)
99%
>99%
a
Concentration of HNO3in the U( VI)solution
0.1
>99%
Transmitance (a.u.)
SI-9 FT-IR characterization
Si-OH
O=U=O
Si-OH
MMSN10N
MMSN10N-Adsorped
MMSN10N-Desorped
4000
3000
2000
1000
Wavenumbercm-1
Fig. S5 The FT-IR of adsorbent characterized during the process
SI-10
PXRD characterization
Intensity
MMSN10N-adsorbed
MMSN10N
1
1
2
3
4
2
3
4
5
5
6
6
7
8
7
8
2Theta(degree)
Fig. S6 The low-angle PXRD of sorbent characterized during the process, picture in the right is the
low-angle PXRD of desorbed MMSN10N
SI-11 Selectivity Test
Table S4 Compositions of the coexistent ions solution
Coexistent ion
Reagent
Reagent purity
U
UO2(NO3)2·6H2O
Standard reagent
Co
Co(NO3)2•6H2O
AR
Ni
Ni(NO3)2•6H2O
AR
Zn
Zn(NO3)2•6H2O
AR
La
La(NO3)3•6H2O
AR
Sm
Sm(NO3)3•6H2O
99.9% metal basis
Sr
Sr(NO3)2
AR
Yb
Yb(NO3)3•5H2O
99.9% metal basis
Nd
Nd(NO3)3•6H2O
AR
Gd
Gd(NO3)3•6H2O
AR
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