Materials 2016, 9, 927; doi:10.3390/ma9110927. S1 of S6. Supplementary ... of the two weight loss platforms is supposed to be the weight loss point of g-C3N4.
Materials 2016, 9, 927; doi:10.3390/ma9110927
S1 of S6
Supplementary Materials: ZnO-Layered Double Hydroxide@Graphitic Carbon Nitride Composite for Consecutive Adsorption and Photodegradation of Dyes under UV and Visible Lights Luhong Zhang, Li Li, Xiaoming Sun, Peng Liu, Dongfang Yang and Xiusong Zhao Zn 2p
(a)
(b)
C 1s
Intensity(a.u)
Al 2p 0
C 1s
200
(c)
400
600
276
800 1000 1200
Binding energy (eV)
2p5/2
Intensity(a.u)
284
288
Binding energy (eV)
(d)
Zn 2p
2p3/2
280
292
O 1s
Intensity(a.u)
Intensity(a.u)
O 1s
1020 1026 1032 1038 1044 1050
Binding energy (eV)
524
528
532
Binding energy (eV)
536
(e)
Intensity(a.u)
Al 2p
66
68
70
72
74
76
Binding energy (eV)
78
80
Figure S1. XPS spectra of ZnO-LDH. (a) Survey spectrum for ZnO-LDH; (b) High-resolution C 1s XPS spectrum of ZnO-LDH; (c) High-resolution XPS spectrum for Zn 2p of ZnO-LDH; (d) High-resolution XPS spectrum for O 1s of ZnO-LDH; (e) High-resolution XPS spectrum for Al 2p of ZnO-LDH.
Materials 2016, 9, 927; doi:10.3390/ma9110927
S2 of S6
100 90
14.30%
80
33.76%
Weight (%)
70 60 50 40 30 20
ZnO-LDH C3N4
10
ZnO-LDH@C3N4
0
0
100
200
300 400 500 Temperature (oC)
600
700
Figure S2. Weight loss of ZnO-LDH, g-C3N4 and ZnO-LDH@C3N4 composite determined by TGA.
There is a slow weight loss before 500 °C for g-C3N4. The first stage with 17.0 wt % mass loss was caused by the loss of surface hydroxyl groups and absorbed water molecules, which was followed by the decomposition of defects and edge functional groups such as uncondensed amine functional group and the edge cyano-group of polymer g-C3N4. Then there is a sharp weight loss during 500–600 °C, which indicates the disintegration of the whole g-C3N4 polymer. Thus, the crossing point of the two tangents of the two weight loss platforms is supposed to be the weight loss point of g-C3N4. The weight loss rate for ZnO-LDH and ZnO-LDH@C3N4 are 14.3% and 33.8% respectively. The difference is 19.5%, which is more than the experimental result 14.6 wt % for the content of g-C3N4. The larger difference should be ascribed to the larger relative amount of LDH in ZnO-LDH@C3N4, which is confirmed by the XRD patterns.
250000
200000
Table count
ZnO-LDH@C3N4 g-C3N4
150000
ZnO-LDH
100000
50000
0
0
20
40 60 Zeta potential (mV)
80
100
Figure S3. Zeta potential of g-C3N4, ZnO-LDH, and ZnO-LDH@C3N4 aqueous suspensions.
The zeta potentials of g-C3N4, ZnO-LDH and ZnO-LDH@C3N4 were measured at room temperature. Typically, each sample powder (20 mg) was dispersed in 20 mL of MQ water by ultrasonication for 30 min. The initial pH values for g-C3N4, ZnO-LDH, and ZnO-LDH@C3N4 aqueous suspensions are 3.29, 7.17 and 6.22 respectively. When the pH value for g-C3N4 aqueous suspension is adjusted into 13.89, the zeta potential is −23.1 mV.
Materials 2016, 9, 927; doi:10.3390/ma9110927
S3 of S6
Figure S4. (a) TEM image for bulk g-C3N4; (b) SEM image for g-C3N4; (c) TEM image for ZnO-LDH.
Materials 2016, 9, 927; doi:10.3390/ma9110927
S4 of S6
20000
Intensity (count)
B 15000
10000
O
Zn
Al
C
5000
Zn Zn
0
0
1
2
3
4
5
6
7
8
9
10
Energy(keV)
Figure S5. (A) HRTEM image for the composite ZnO-LDH@C3N4; (B) EDX spectrum of ZnO-LDH@C3N4.
Figure S6. The elemental mapping for ZnO-LDH@C3N4.
Materials 2016, 9, 927; doi:10.3390/ma9110927
S5 of S6
400
350
Volume adsorbed (cm3g-1)
300
a b c
250
200
150
100
50
0 0.0
0.2
0.4
0.6
0.8
1.0
Relative Pressure (P/P0) Figure S7. N2 adsorption/desorption of isotherms of (a) g-C3N4; (b) ZnO-LDH and (c) ZnO-LDH@C3N4. 110
100
(A)
98
105
96
95 90
92
85
C/C0(%)
94
90 88 86
80 75 70 65
84
60
82
55 50
80 -5
0
5 10 15 20 25 30 35 40 45 50 55 60 65
-2
0
2
4
6
Time (min)
8
10 12 14 16 18 20 22 24 26
Time (h)
Figure S8. The adsorption dynamics of g-C3N4 (A) and ZnO-LDH (B) in OrgII adsorption.
ZnO-LDH@C3N4
Transmittance (a.u.)
C/C0(%)
(B)
100
after 1h adsorption of OrgII
after 24h adsorption of OrgII
3900 3600 3300 3000 2700 2400 2100 1800 1500 1200 900 -1 Wavenumber (cm )
Figure S9. FT-IR spectra of ZnO-LDH@C3N4, ZnO-LDH@C3N4 after OrgII adsorption in 1 h and ZnO-LDH@C3N4 after OrgII adsorption in 24 h.
Materials 2016, 9, 927; doi:10.3390/ma9110927
S6 of S6
FT-IR spectra of ZnO-LDH@C3N4 samples before and after OrgII adsorption in 1 h and 24 h were shown in Figure S9. The peaks at 810 cm−1 assigned to the bending vibration of heptazine rings became sharper along with the adsorption time and changed into multi-peaks after saturated adsorption of OrgII, which may be induced by the molecular cooperation between adsorbed OrgII and g-C3N4. 100
Degradation percentage (%)
80
60
40
20
0 0
1
2
3
Recycle time
4
5
Figure S10. The cycling runs of ZnO-LDH@C3N4 in the photodegradation of MB under UV irradiation.
