Electronic Supplementary Material (ESI) for Journal of Materials Chemistry A.
This journal is © The Royal Society of Chemistry 2016
Hierarchical iron-containing MnO2 hollow microspheres assembled
by thickness-tunable nanosheets for efficient phosphate removal
Xiao Ge,a,b Xiangyang Song,a Yue Ma,a Hongjian Zhou,a Guozhong Wang,a Haimin Zhang,a
Yunxia Zhang,a,* Huijun Zhao,a,c and Po Keung Wongd
a Key
Laboratory of Materials Physics, Centre for Environmental and Energy Nanomaterials,
Anhui Key Laboratory of Nanomaterials and Nanotechnology, Institute of Solid State Physics,
Chinese Academy of Sciences, Hefei 230031, China.
b
c
University of Science and Technology of China, Hefei 230026, P. R. China
Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland
4222, Australia.
d
School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China
Fig. S1 SEM image of pure γ-MnO2 sample.
Fig. S2 FESEM images of the obtained Fe containing γ-MnO2 microspheres using FeCl2 as iron precursor: (a) FMO-1; (b) FMO-2; (c)
FMO-3.
*
Correspondence Author. Email: [email protected]
Fax: +86-551-65591434; Tel: +86-551-65592145
Fig. S3 N2 adsorption–desorption isotherm and the corresponding pore-size distribution (the inset) of the obtained products: I. γ-MnO2; II.
FMO-1; III. FMO-2; IV. FMO-3.
Fig. S4 XRD patterns of FMO-3 samples under different reaction time: I. 5 min; II. 30 min; III. 2h.
25
Qt (mg/g)
20
IV
15
10
III
5
II
I
0
0
50
100
150
200
Time (min)
Fig. S5 Nonlinear least squares (NLLS) adjustment for the kinetic data on different absorbents: I. γ-MnO2; II. FMO-1; III. FMO-2; IV.
FMO-3. Experimental conditions: 10 mg·L-1 of initial phosphate concentration, 0.5 g·L-1 of sorbent dosage, pH 7, and temperature 25◦C.
Table S1 The parameters of the Langmuir and Freundlich isotherm models for phosphate adsorption by different
absorbents.
Material
Langmuir model
qmax
(mgg-1)
KL
(Lmg-1)
Freundlich model
R2
KF (mgg-1)
1/n
R2
γ-MnO2
0.62
0.009
0.9801
0.0253
0.9755
0.9650
FMO-1
9.65
0.013
0.9799
0.0394
1.0868
0.9345
FMO-2
26.04
0.039
0.9877
2.4422
0.4813
0.9570
FMO-3
112.36
0.049
0.9911
15.5157
0.4044
0.9346
Fig. S6 Distribution of phosphate species under different pH.
8
Phosphate removal
Final pH
99.8
7
99.6
6
99.4
5
99.2
4
99.0
Final pH
Phosphate removal (%)
100.0
3
98.8
2
98.6
1
2
3
4
5
6
7
8
9
10
Initial pH
Fig. S7 Effect of initial solution pH on removal efficiency of PO43- by FMO-3 and final solution pH as a function of initial pH (Initial
PO43- concentration 10 ppm, adsorbent dose 0.5 g·L-1, temperature 25 ◦C).
Fig. S8 Effect of HCO3- on removal efficiency of PO43- by FMO-3 and final pH as a function of initial pH (Initial PO43- concentration 10
ppm, adsorbent dose 0.5 g·L-1, temperature 25 ◦C).
Fig. S9 SEM image of the FMO-3 sample after phosphate treatment.
Table S2 Characteristics of water sampled from Nanfei River
Parameter
Value
Parameter
Value
K+ (mgL-1)
17.90 ± 0.07
Mg2+ ( mgL-1)
9.01 ± 0.02
Ca2+ ( mgL-1)
37.72 ± 0.12
DOC (mg C/L)
30.2 ± 0.20
Na+
63.88 ± 0.60
pH
7.50 ± 0.10
Cl-
(
mgL-1)
(
mgL-1)
42.82 ± 0.05
NO3 (
mgL-1)
2-
mgL-1)
32.73 ± 0.20
SiO32-
mgL-1)
2-
mgL-1)
24.34 ± 3.03
SO4 (
CO3 (
-
(
42.43 ± 0.09
0.73 ± 0.04