supplementary information influence of facets and ...s1 supplementary information influence of...
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S1
Supplementary Information
Influence of Facets and Heterojunctions in
Photoactive Bismuth Oxyiodide
Aijuan Han,a,b Jiulong Sun,a,b Xuanhao Lin,a Cheng-Hui Yuan,a Gaik Khuan Chuah*a
and Stephan Jaenicke*a
a Department of Chemistry, National University of Singapore, 3 Science Drive 3,
Singapore 117543, Singapore
b NUS Environmental Research Institute, National University of Singapore, 5A
Engineering Drive 1, #02-01, Singapore 117411, Singapore
Electronic Supplementary Material (ESI) for RSC Advances.This journal is © The Royal Society of Chemistry 2015
S2
Fig. S1 UV-vis diffuse reflectance spectra of BiOI samples synthesized at
different pH.
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
200 300 400 500 600 700 800
Ku
be
lka
-M
un
k F
un
ctio
n
Wavelength (nm)
pH 2.3
pH 3
pH 4
pH 5
pH 6
pH 7
pH 8
S3
Fig. S2 BiOI samples prepared at different pH.
BiOI-pH2.3 BiOI-pH3 BiOI-pH4
BiOI-pH6 BiOI-pH7 BiOI-pH8BiOI-pH5
S4
Fig. S3 Kinetic plots for p-cresol photodegradation over BiOI prepared at
different pH.
0
1
2
3
4
0 2 4 6 8
ln(C
0/C
)
Time (h)
pH 2.3
pH 3
pH 4
pH 5
pH 6
pH 7
pH 8
S5
Fig. S4 TGA and derivative weight loss for BiOI-pH6.
-0.7
-0.6
-0.5
-0.4
-0.3
-0.2
-0.1
-1E-15
60
65
70
75
80
85
90
95
100
0 200 400 600 800
De
riva
tive
we
igh
t (%
/oC
)
We
igh
t (%
)
T (oC)
17 %
Bi 4
O5I 2
19 %
Bi 7
O9I 3
27 %
Bi 5
O7I
32 %
Bi 2
O3
S6
Fig. S5 X-ray diffractograms (25o to 40o) of as-synthesized and calcined
BiOI-pH6 samples.
25 30 35 40
Inte
nsity (cp
s)
2 theta (o)
BiOI-pH6
* BiOI▲ Bi4O5I2Bi7O9I3○ Bi5O7I
**
* *
○
○ ○○
○ ○
○
○
○
○○
▲*
▲ *
○
BiOI-pH6-300-1
BiOI-pH6-350-1
BiOI-pH6-350-3
BiOI-pH6-350-5
BiOI-pH6-400-1
S7
Fig. S6 SEM images of (a) BiOI-pH6-300-1, (b) BiOI-pH6-350-1,
(c) BiOI-pH6-350-5, and (d) BiOI-pH6-400-1.
(a) (b)
(c) (d)
S8
Fig. S7 UV-vis diffuse reflectance spectra of BiOI-pH6 calcined at 300 - 400 ℃
for 1 to 5 h
0
2
4
6
8
10
12
200 400 600 800
Ku
be
lka
-Mu
nk F
un
ctio
n
Wavelength (nm)
pH6
pH6-300-1
pH6-350-1
pH6-350-3
pH6-350-5
pH6-400-1
S9
Fig. S8 BiOI-pH6 calcined at different temperatures and times.
BiOI-pH6 BiOI-pH6-300-1
BiOI-pH6-350-1 BiOI-pH6-350-3
BiOI-pH6-350-5 BiOI-pH6-400-1
S10
Fig. S9 Total and partial density of state of BiOI.
0
3
6
9
12
-20 -10 0 10 20
Energy (eV)
total
O
I
Bi
TDOS for BiOI
0
3
6
9
12/
eV
cell)
s
pPDOS for O
0
3
6
9
12
DO
S (S
tate
tes
s
p
PDOS for I
0
3
6
9
12
15s
pPDOS for Bi
S11
Fig. S10 Total organic carbon and degradation efficiency for p-cresol versus time
over BiOI-pH6-350-3.
0
20
40
60
80
100
0
4
8
12
16
20
0 0.5 1 1.5 2
DE
(%
)
TO
C (
pp
m)
Time (h)
S12
Compound X (eV) Eg (eV) EVB (eV) ECB (eV)
BiOI 5.94 1.90 2.39 0.49
Bi4O5I2 5.39 2.04 1.91 -0.13
Bi7O9I3 5.46 2.56 2.24 -0.32
Bi5O7I 5.92 3.16 3.00 -0.16
Fig. S11 Conduction and valence band positions of various bismuth oxyiodides.
-1.0
0.0
1.0
2.0
3.0
4.0
5.0
E /
eV
Bi4O5I2
BiOI
2.5
6 e
V
3.1
6 e
V
2.0
4eV
1.9
eV
Bi7O9I3 Bi5O7I
S13
Fig. S12 (a) Photodegradation efficiency for p-cresol over recycled BiOI-pH6-350-3
and (b) x-ray diffractograms of fresh and used BiOI-pH6-350-3.
0
20
40
60
80
100
1 2 3 4
DE
(%
)
Run
(a)
5 15 25 35 45 55 65 75
Inte
nsity (cp
s)
2 theta (o)
fresh
recycled
(b)
S14
Fig. S13 Photocatalytic degradation of p-cresol over BiOI-pH6-350-3 in the presence
of 1 mmol/L NaCl and NH4NO3.
0
20
40
60
80
100
0 0.5 1 1.5 2
DE
(%
)
Time (h)
NaCl
NH4NO3
no
S15
Fig. S14 Fluorescence spectrum of terephthalic acid solution after different
illumination times in the presence of BiOI-pH6-350-3.
0
40000
80000
120000
350 400 450 500 550 600
Flu
ore
sce
nce
Wavelength (nm)
0 min
30 min
60 min
120 min
S16
106.8
139.7
214.7
-MS, 13.7min #1970
0
1
2
3
4
5
6x10
Intens.
100 150 200 250 300 350 400 450 m/z
(a)
92.9
105.8
122.7
145.6
155.6
170.7 198.7 212.8
246.7
282.9 325.1 339.1353.1 381.2 395.1 412.2 440.2 454.3 468.2 496.2
-MS, 3.7min #534
0
1
2
3
4
5
6
5x10
Intens.
100 150 200 250 300 350 400 450 m/z
(b)
120.7
126.6
145.6
156.7
170.7
-MS, 6.1min #867
0.00
0.25
0.50
0.75
1.00
1.25
1.50
5x10
Intens.
80 100 120 140 160 180 200 220 m/z
(c)
S17
Fig. S15 Mass spectra of species detected in p-cresol photodegradation (a) p-cresol
and (b-e) degradation intermediates.
170.7 184.7
212.7
226.7
254.9
268.9
283.0
297.0 313.0 323.0 339.0 351.2
365.1386.1
393.2407.1
423.2437.2
451.3
-MS, 26.2min #3755
0.0
0.5
1.0
1.5
2.0
2.55x10
Intens.
200 250 300 350 400 450 m/z
(d)
126.6
136.6
145.6
184.7
212.7
254.9
282.9
296.9 323.0353.1
367.1384.1
398.1409.2 423.2 437.3 454.2 468.2 482.2
-MS, 26.5min #3801
0.0
0.5
1.0
1.5
2.0
5x10
Intens.
100 150 200 250 300 350 400 450 m/z
(e)
S18
S1. Theoretical calculation of the angles between different planes
The theoretical value for the angles (φ) between different (hkl) planes of tetragonal
BiOI is determined by the following formula:
cosφ =
1a2
(h1h2 + k1k2) +1c2
l1l2
√[1a2
(h12 + k1
2) +1c2
l12][
1a2
(h22 + k2
2) +1c2
l22]
The angle between (110) and (200) is 45.0 o, while the angle between )( 131 and
)( 101 is 42.8 o using a = 0.3994 nm and c = 0.9149 nm.