Electronic Supplementary Information
Interfacial restructuration of carbon nitride polymers for
visible-light photocatalysis
Feng Lin, Zihao Yu, Xinchen Wang*
State Key Laboratory of Photocatalysis on Energy and Environment, College of
Chemistry, Fuzhou University, Fuzhou 350002, People’s republic of China
Email: [email protected]
Experimental section
Materials. 3,5-Dibromobenzoic acid, triethylamine, 1,4-Phenylenediboronic acid,
1,3,6,8-tetrabromopyrene, 4,4’-dibromo-2,2’-bipyridy, SOCl2 and Pd(PPh3)4 are all of
analytic grade and used without further modification or purification.
N,N-dimethylformamide was purified by distillation under reduced pressure after
drying with diphosphorus pentaoxide; CH2Cl2 and ethanol were purified by
distillation with calcium hydride, which were all strict in dehydration treatment.
PCN. The polymeric carbon nitride was synthesized as described previously.1
Covalence bonds bridged PCN (CCN): A certain amount of 3,5-Dibromobenzoic
acid was dissolved in SOCl2 solution with few drops of anhydrous THF and refluxed
for three hours under dried N2. After cool to the room temperature, excessive thionyl
chloride was removed at moisture-free and vacuo conditions. Dibromobenzoic acid
chloride was slowly dropped into dried CH2Cl2 dispersing PCN powder under 0°C
with equivalent of triethylamine. After 5h, the yellowishandgreen precipitates were
obtained by rotary evaporation and centrifugal separation with the absolutely fresh
anhydrous ethanol solution and water, then dried at 60 ºC for 24h.
Hydrogen bonds decorated polymeric carbon nitride (HCN): Firstly, dispersed
Electronic Supplementary Material (ESI) for ChemComm.This journal is © The Royal Society of Chemistry 2019
PCN powder into the absolutely fresh anhydrous ethanol solution, with
monodispersed 3,5-Dibromobenzoic acid (2mmol/L) for 24h at room temperature.
Then, centrifuged with absolutely fresh anhydrous ethanol solution and dried.
CCN-EG and HCN-EG: A three necked flask equipped with magnetic stir bar was
charged with the mixtures of 1,4-Phenylenediboronicv acid (1mmol), Pd(PPh3)4
(1.2mol%), 1,3,6,8-tetrabromopyrene (0.4mmol), 4,4’-dibromo-2,2’-bipyridy
(0.15mmol) and CCN (0.5g) under dried N2 atmosphere. The K2CO3 aqueous solution
and N,N-dimethylformamide were slowly added into the above reactor under
vigorous stirring; then, refluxed until the reaction was complete which was judged by
the thin layer chromatography (TLC) analysis. After cooling to the room temperature,
the strong yellowish green precipitate were purification with H2O and methanol
several times and further extracted with tetrahydrofuran and methanol by Soxhlet for
48h, respectively. The product was dried under reduce pressure and further dried in
the vacuum oven at 60 ºC for 24h. The product is about 73.5% and 67.2% yield for
CCN-EG and HCN-EG compared with the bulk PCN.
Characterization: The C K-edge and N K-edge X-ray absorption near-edge spectra
(XANES) were measured at BL12B-a beamline of National Synchrotron Radiation
Laboratory (NSRL, China) in the total electron yield (TEY) mode by collecting the
sample drain current under a vacuum better than 5×10-8
Pa. The beam from the
bending magnet was monochromatized utilizing a varied linespacing plane grating
and refocused by a toroidal mirror. The energy range is 100–1000 eV with an energy
resolution of ca. 0.2 eV. X-ray diffraction (XRD) measurements were performed at
Bruker D8 Advance diffractometer equipped with monochromatic Cu Kα radiation
(λ=1.5418Å). Scanning electron microscope (SEM) images were conducted on a LEO
Gemini 1530 (Carl Zeiss AG, Germany) using an in lens SE detector. Fourier
transformed infrared (FTIR) spectra were recorded using a Nicolet Magna 670 FTIR
spectrometer. The solid-state 13
C nuclear magnetic resonance (NMR) spectra were
recorded on a Bruker Advance III 500 spectrometer. Transmission electron
microscopy (TEM) was performed on a FEI Tencai 20 microscope. The photocurrent
performance analysis was performed using a BioLogic VSP-300 electrochemical
system. The nitrogen adsorption–desorption isotherms were collected at 77 K using a
Micromeritics ASAP 2020 surface area and porosity analyzer. The X-ray
photoelectron (XPS) spectra were carried out on an ESCALAB 250 (Thermo Fisher
Scientific) operating with Al Kα radiation (hʋ=1486.6 eV; analysed area = 600 μm2).
The base pressure of the analyzer chamber was around 5×10-8
Pa. An elemental
surface analysis was first executed, for each sample, in the range of 0–1200 eV with
Fixed Retard Ratio mode. Raman spectroscopic measurements were performed on a
Renishaw in Via Raman System 1000 with a 325 nm Nd:YAG excitation source at
room temperature.
Photocatalytic HER Test. Hydrogen evolution reactions were carried out in a closed
glass gas system where is connected to a Pyrex top-irradiation reaction vessel. Firstly,
50 mg of catalyst powders were dispersed in an aqueous solution (100mL) with 10mL
sacrificial agent and 3wt% Pt with H2PtCl6. After removing air completely, the
reaction solution was irradiated with a 300W Xeon lamp with the working current of
15A (Shenzhen ShengKang Technology Co., Ltd, China, LX300F). In order to rule
out the short-pass light, the long-pass cut-off filter was applied to correct the incident
light. The evolved gases were analyzed by gas chromatography equipped with a
thermal conductive detector (TCD).
Photocatalytic CO2 reduction. 30mg catalyst, 1mL triethanolamine (TEOA) and
1μmol CoCl2, 15mg 2,2-bipyridine, 5mL acetonitrile were added to the reactor,
respectively. After degassing and backfilling with pure CO2, the reaction was carried
out with 300W Xe lamp equipped with a 420nm cut-off filter and maintained at 30◦C.
After reaction, the gases were analyzed by using gas chromatography.
The apparent quantum yield (AQY) measurement. The AQY for hydrogen
generations were carried out by using monochromatic LED lamps with band pass
filter of 420 ± 4.6, 470 ± 4.4, 490 ± 3.8, 520 ± 4.0, respectively. The intensity of each
top-irradiation LED lamps were 14.3, 11.2, 7.6, 2.9 mW cm-1
which is determinate by
ILT 950 spectroradiometer. The effective irradiation area was controlled as 9 cm2(3×3
cm2). Since an average of one hour hydrogen produced, the AQY was calculated as
follow:
%1002
%100
tPS
NMch
N
NAQY A
p
e
Where, h refers to the Planck constant, c is the speed of light, M is behalf of the total
hydrogen generation in one hour, NA is the Avogadro constant, S is the effective
irradiation area, P is the intensity of fixed irradiation light, t is the reaction time of
hydrogen evolution reaction, λ just is the wavelength of the irradiation light.
396 398 400 402 404Photon Energy / eV
400eV
PCN
CCN-EG
HCN-EG
No
rma
lize
d
(E)
399eV
(a)
Fig. S1 The enlarged N K-edge for PCN, CCN-EG and HCN-EG.
1200 1000 800 600 400 200 0
HCN-EG
Binding Energy / eV
PCN
CCN
CCN-EG
HCN
Fig. S2 Representative XPS survey spectra PCN, CCN, CCN-EG, HCN and
HCN-EG.
298 296 294 292 290 288 286 284 282 280
raw
fit
background
C-C/C-H
N=C-N
-
C-O/C-NHx
Inte
nsity /
CP
S
(a)
Binding Energy / eV
298 296 294 292 290 288 286 284 282 280Binding Energy / eV
Inte
nsity /
CP
S
raw
fit
background
N=C-N
-
C-C/C-H
C-O/C-NHx
(b)
Fig. S3. The C1s XPS of CCN (a) and HCN(b).
Table S1 The present chemical environments, binding energy and their corresponding
relative bond contents of C1s for samples.
Sample Chemical states Binding energy
(eV) Cont.%
PCN
C-C/C-H 284.8 6.05
N=C-N 288.3 93.95
- 294.0 --
CCN
C-C/C-H 284.8 11.04
C-O/C-NHx 285.5 5.60
N=C-N 288.4 83.36
- 294.1 --
HCN
C-C/C-H 284.7 10.52
C-O/C-NHx 285.8 2.79
N=C-N 288.2 86.70
- 293.7 --
CCN-EG
C-C/C-H 284.8 10.75
C-O/C-NHx 285.5 5.12
N=C-N 288.4 78.41
- 293.2 --
HCN-EG
C-C/C-H 284.8 10.81
C-O/C-NHx 285.9 2.02
N=C-N 288.3 71.70
- 293.1 --
200 175 150 125 100
PCN
CCN
HCN
Chemical Shift / ppm
Inte
nsity / a
.u.
149.4
Fig. S4 the solid state 13
C NMR results of PCN, CCN and HCN
412 410 408 406 404 402 400 398 396 394
raw
fit
background
C-N=C
N-C3
C-NH2
C-N=O
Inte
nsity / C
PS
Binding Energy / eV
CCN
(a)
412 410 408 406 404 402 400 398 396 394
raw
fit
background
C-N=C
N-C3
C-NH2
-
Inte
nsity /
CP
S
Binding Energy / eV
HCN
(b)
Fig. S5 The N1s XPS of CCN and HCN.
Table S2. The present chemical environments, binding energy and their
corresponding relative bond contents of N1s for samples.
Sample Chemical states Binding energy
(eV) Cont.%
PCN
C-N=C 398.6 49.57
N-C3 399.4 30.53
C-NHx 400.8 19.89
- 404.6 --
CCN
C-N=C 398.7 45.58
N-C3 399.4 30.45
C-NHx 400.3 15.03
C-N=O 401.4 8.92
- 404.8 --
HCN
C-N=C 398.6 47.52
N-C3 399.5 35.9
C-NHx 401.0 16.48
- 404.9 --
CCN-EG
C-N=C 398.5 35.86
N-C3 399.1 29.44
C-NHx 399.9 23.55
C-N=O 401.2 11.14
- 405.1 --
HCN-EG
C-N=C 398.7 53.84
N-C3 399.6 33.68
C-NHx 401.0 12.47
- 405.4 --
540 538 536 534 532 530 528
raw
fit
background
OH
COOH
Binding Energy / eV
Inte
nsity /
CP
S
PCN
(a)
528 530 532 534 536 538 540Binding Energy / eV
Inte
nsity /
CP
S
raw
fit
background
OH
COOH
CCN
(b)
528 530 532 534 536 538 540Binding Energy / eV
Inte
nsity /
CP
S
raw
fit
background
COOH
OH
HCN
(c)
540 538 536 534 532 530 528Binding Energy / eV
Inte
nsity /
CP
S
raw
fit
background
COOH
OH
CCN-EG
(d)
538 536 534 532 530 528Binding Energy / eV
Inte
nsity /
CP
S
raw
fit
background
OH
COOH
HCN-EG
(e)
Fig. S6 The O1s XPS of PCN, CCN, HCN, CCN-EG and HCN-EG.
Table S3. The present chemical environments, binding energy and their
corresponding relative bond contents of O1s for samples.
Sample Chemical states Binding energy
(eV) Cont.%
PCN COOH 535.5 28.39
C-OH 532.9 71.61
CCN COOH -- --
C-OH 532.9 100
HCN COOH 533.9 33.58
C-OH 532.3 66.42
CCN-EG COOH 533.5 49.27
C-OH 532.0 50.73
HCN-EG COOH 533.5 76.13
C-OH 531.9 23.87
76 74 72 70 68 66
Binding Energy / eV
Inte
nsity / C
PS
CCN
HCN
CCN-EG
HCN-EG
Fig. S7 The Br3d XPS of CCN, HCN, CCN-EG and HCN-EG.
200 198 196 194 192 190 188 186 184 182
In
ten
sity /
CP
S
CCN-EG
HCN-EG
Binding Energy / eV
Fig. S8 The B1s XPS of CCN-EG and HCN-EG.
350 348 346 344 342 340 338 336 334 332
HCN-EG
Inte
nsity /
CP
S
Binding Energy / eV
CCN-EG
Fig. S9 The Pd3d XPS of CCN-EG and HCN-EG.
10 20 30 40 50 60 70
CCN-EG
HCN-EG
PCN
HCN
CCN
Inte
nsi
ty
2
(a)
N
N
N
N
N N
N
(002)
10 11 12 13 14 15
CCN-EG
CCN
HCN-EG
PCN
HCN
(b)
Fig. S10 The XRD results of catalysts
4000 3600 3200 2800 2400 2000 1600 1200 800 400
HCN-EG
Inte
nsi
ty
Wavenumber / cm-1
(a)
CCN-EG
HCN
CCN
PCN
0 500 1000150020002500300035004000
PCN
CCN
CCN-EG
HCN
HCN-EG
Raman Shift / cm-1
Inte
nsity / a
.u.
(b)
Fig. S11 The IR and Raman results of samples.
0.0 0.2 0.4 0.6 0.8 1.0
0
50
100
150
200
250
300
Volu
me
Abso
rbed
/ c
m3 g
-1
P / P0
Pore volume / cm-3 g
-1
Sample Pore volume / cm3 g-1 Pore size / nm
PCN 94.4 0.43 20.31
CCN 56.68 0.32 16.82
CCN-EG 89.4 0.22 20.47
SBET
/ m2 g
-1
PCN
CCN
CCN-EG
(a)
0 10 20 30 40 50 600.000
0.002
0.004
0.006
0.008
0.010 PCN
CCN
CCN-EG
Pore dimeter / nm
dV
/dD
/ c
m3 n
m-1 g
-1
(b)
0.0 0.2 0.4 0.6 0.8 1.0
0
50
100
150
200
250
300
P / P0
Volu
me
Abso
rbed
/ c
m3 g
-1 S
BET / m
2 g
-1SBET
/ m2 g
-1S
BET / m
2 g
-1
Sample Pore volume / cm3 g-1 Pore size / nm
PCN 94.4 0.43 20.31
HCN 49.91 0.17 12.02
HCN-EG 90.8 0.45 19.49
CN
HCN
HCN-EG
SBET
/ m2 g
-1
(c)
0 10 20 30 40 50 60
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
Pore dimeter / nm
dV
/dD
/ c
m3 n
m-1 g
-1
PCN
HCN
HCN-EG
(d)
Fig. S12 Typical N2 adsorption-desorption isotherm of samples. The specific surface
area was investigated via the Brunauer-Emmett-Teller (BET) method and the pore
size was studied by using Barret-Joyner-Halenda (BJH) model.
Fig. S13 Typical Transmission electron microscope images of CCN-EG and
HCN-EG.
Fig. S14 The SEM images of samples.
-1.4-1.2-1.0-0.8-0.6-0.4-0.20.0 0.2 0.4 0.6 0.8 1.00.00
0.15
0.30
0.45
0.60
1.5 K
1 K
0.5 K
-1.3 eV
E / V vs. NHE pH=7.0
C-2
/ F
-2
PCN
-1.8-1.6-1.4-1.2-1.0-0.8-0.6-0.4-0.20.0 0.2 0.4 0.6 0.8 1.00.00
0.02
0.04
0.06
0.08
0.10
0.12
C-2
/ F
-2
E / V vs. NHE pH=7.0
1.5 K
1 K
0.5 K
-1.4 eV
CCN
-1.4-1.2-1.0-0.8-0.6-0.4-0.20.0 0.2 0.4 0.6 0.8 1.00.00
0.05
0.10
0.15
0.20
0.25
0.30
E / V vs. NHE pH=7.0
C-2
/ F
-2
1.5 K
1 K
0.5 K
-1.02 eV
CCN-EG
-1.4-1.2-1.0-0.8-0.6-0.4-0.20.0 0.2 0.4 0.6 0.8 1.00.00
0.05
0.10
0.15
0.20
0.25
0.30 1.5 K
1 K
0.5 K
-1.28 eV
E / V vs. NHE pH=7.0
C-2
/ F
-2
HCN
-1.4-1.2-1.0-0.8-0.6-0.4-0.20.0 0.2 0.4 0.6 0.8 1.00.00
0.05
0.10
0.15
0.20
E / V vs. NHE pH=7.0
C-2
/ F
-2
1.5 K
1 K
0.5 K
-1.16 eV
HCN-EG
Fig. S15 Mott-Schottky plots of the samples.
Fig. S16 UV-Vis diffuse reflectance spectra (DRS) of two types of surface chemical
decoration.
400 420 440 460 480 500 520 540 560 580
PCN
CCN
CCN-EG
Wavelengh / nm
PL I
nte
nsity
400 420 440 460 480 500 520 540 560 580
PCN
HCN
HCN-EG
PL In
ten
sity
Wavelengh / nm
Fig. S17 PL spectra.
0.00 25.00k 50.00k 75.00k 100.00k0.0
20.0k
40.0k
60.0k
80.0k
100.0k
120.0k
140.0k
Z/
Z/
PCN
CCN
CCN-EG
0.00 25.00k 50.00k 75.00k 100.00k0.0
20.0k
40.0k
60.0k
80.0k
100.0k
120.0k
140.0k
Z/
Z/
PCN
HCN
HCN-EG
Fig. S18 Electrochemical impedance spectrum.
100 150 200 250 300-10
-8
-6
-4
-2
0
2
PCN
CCN
CCN-EG
off
Time / s
Curr
ent density /
A
cm
-2
on
200 225 250 275 300-8
-6
-4
-2
0
2
PCN
HCN
HCN-EG
offon
Curr
ent density /
A
cm
-2
Time / s
Fig. S19 Photocurrent density in chemical and hydrogen bond modified PCN.
0
50
100
150
200
250
300
HCN-EGCCN-EGHCNPCN CCN
H2 e
vo
luti
on
/
mo
lh
-1
Fig. S20 The H2 production of modified PCN
0 1 2 3 4 50
5
10
15
20
25
30
H2 e
vo
luti
on /
m
olh
-1
CCN
Variety concentration of assembled DBP mmol / L
0 1 2 3 4 520
30
40
50
60
70
HCN
Variety concentration of assembled DBP mmol / L
H2 e
volu
tion /
mol
h-1
Fig. S21 The changed H2 production after variety concentration of DBM molecules
anchored upon CCN and HCN.
0 2 4 6 8 10 12 14 16
0
10
20
30
40
50 CCN
Pro
ducte
d H
2 /
m
olh
-1
t / h
0 2 4 6 8 10 12 14 16
0
50
100
150
200HCN
t / h
Pro
du
cte
d H
2 /
m
olh
-1
Fig. S22 Photocatalytic activity of CCN and HCN.
10 20 30 40
HCN
CCN
Inte
nsity
2
4000 3500 3000 2500 2000 1500 1000
HCN
CCN
Wavelength / cm-1
Fig. S23 XRD and FT-IR of recycled CCN and HCN.
10 20 30 40
HCN-EG
2
Inte
nsity
CCN-EG
4000 3500 3000 2500 2000 1500 1000
HCN-EG
Wavelength / cm-1
CCN-EG
Fig. S24 XRD and FT-IR of recycled CCN-EG and HCN-EG.
Table S4. The elemental analysis (EA) results of CCN-EG, HCN-EG and recycled
catalysts
C(%) N(%) H(%) C/N (atom
ratio)
CCN-EG 32.54 55.27 2.80 0.68
CCN-EG
-recycled 31.58 55.03 2.54 0.67
HCN-EG 32.68 53.39 2.82 0.71
HCN-EG
-recycled 32.34 55.44 2.65 0.68
Fig. S25 Illustration of the preparation of dye modified.
0 2 4 6 8 10 12 14 16
HCN-EG-Ru
CCN-EG-Ru
CCN-EG
HCN-EG
HCN
CO
H2
Generated Gas / mol / h
PCN
CCN
Fig. S26 Photocatalytic CO2 reduction
1 2 30
2
4
6 CO
H2
CCN-EG
Ge
ne
rate
d G
as /
m
ol / h
1 2 30
1
2
3
4 CO
H2
HCN-EG
Ge
ne
rate
d G
as /
m
ol / h
Fig. S27 The recycling text of CCN-EG and HCN-EG
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