Electronic Supplementary Information

Interfacial restructuration of carbon nitride polymers for

visible-light photocatalysisFeng 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: xcwang@fzu.edu.cn

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 13C 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

tPSNMch

NNAQY 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

Nor

mal

ized

(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

/ C

PS

(a)

Binding Energy / eV

298 296 294 292 290 288 286 284 282 280Binding Energy / eV

Inte

nsity

/ C

PS

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 statesBinding energy

(eV)Cont.%

C-C/C-H 284.8 6.05

N=C-N 288.3 93.95PCN

- 294.0 --

C-C/C-H 284.8 11.04

C-O/C-NHx 285.5 5.60

N=C-N 288.4 83.36CCN

- 294.1 --

C-C/C-H 284.7 10.52

C-O/C-NHx 285.8 2.79

N=C-N 288.2 86.70HCN

- 293.7 --

C-C/C-H 284.8 10.75

C-O/C-NHx 285.5 5.12

N=C-N 288.4 78.41CCN-EG

- 293.2 --

C-C/C-H 284.8 10.81

C-O/C-NHx 285.9 2.02

N=C-N 288.3 71.70HCN-EG

- 293.1 --

200 175 150 125 100

PCN CCN HCN

Chemical Shift / ppm

Inte

nsity

/ a.

u.

149.4

Fig. S4 the solid state 13C 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

/ C

PS

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 statesBinding energy

(eV)Cont.%

C-N=C 398.6 49.57

N-C3 399.4 30.53

C-NHx 400.8 19.89PCN

- 404.6 --

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

CCN

- 404.8 --

C-N=C 398.6 47.52

N-C3 399.5 35.9

C-NHx 401.0 16.48HCN

- 404.9 --

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

CCN-EG

- 405.1 --

C-N=C 398.7 53.84

N-C3 399.6 33.68

C-NHx 401.0 12.47HCN-EG

- 405.4 --

540 538 536 534 532 530 528

raw fit background OH COOH

Binding Energy / eV

Inte

nsity

/ C

PSPCN

(a)

528 530 532 534 536 538 540Binding Energy / eV

Inte

nsity

/ C

PS

raw fit background OH COOH

CCN

(b)

528 530 532 534 536 538 540Binding Energy / eV

Inte

nsity

/ C

PS

raw fit background COOH OH

HCN

(c)

540 538 536 534 532 530 528Binding Energy / eV

Inte

nsity

/ C

PS

raw fit background COOH OH

CCN-EG

(d)

538 536 534 532 530 528Binding Energy / eV

Inte

nsity

/ C

PS

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 statesBinding energy

(eV)Cont.%

COOH 535.5 28.39PCN

C-OH 532.9 71.61

COOH -- --CCN

C-OH 532.9 100

COOH 533.9 33.58HCN

C-OH 532.3 66.42

COOH 533.5 49.27CCN-EG

C-OH 532.0 50.73

COOH 533.5 76.13HCN-EG

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

tens

ity /

CPS

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

/ C

PS

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

Inten

sity

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

Inten

sity

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 A

bsor

bed

/ cm

3 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/d

D / 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 A

bsor

bed

/ cm

3 g-1 SBET / m2 g-1SBET / m2 g-1SBET / m2 g-1

Sample Pore volume / cm3 g-1 Pore size / nm

PCN 94.4 0.43 20.31HCN 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/d

D / 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

-1.8-1.6-1.4-1.2-1.0-0.8-0.6-0.4-0.20.00.20.40.60.81.00.00

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 K1 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 In

tens

ity

400 420 440 460 480 500 520 540 560 580

PCN HCN HCN-EG

PL In

tens

ity

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/

PCNCCN

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

Curre

nt d

ensit

y /

A cm

-2

on

200 225 250 275 300-8

-6

-4

-2

0

2

PCN HCN HCN-EG

offonCu

rrent

den

sity

/ 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

H 2 evo

lutio

n /

molh-1

Fig. S20 The H2 production of modified PCN

0 1 2 3 4 50

5

10

15

20

25

30

H 2 evol

utio

n /

molh-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

H 2 evol

utio

n /

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

Prod

ucte

d H

2 /

mol

h-1

t / h

0 2 4 6 8 10 12 14 16

0

50

100

150

200HCN

t / h

Prod

ucte

d H

2 /

mol

h-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 -

recycled31.58 55.03 2.54 0.67

HCN-EG 32.68 53.39 2.82 0.71

HCN-EG -

recycled32.34 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

Gen

erat

ed G

as / m

ol /

h

1 2 30

1

2

3

4 CO H2

HCN-EG

Gen

erat

ed G

as / m

ol /

h

Fig. S27 The recycling text of CCN-EG and HCN-EG

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