Supporting information

Highly stable single Pt atomic sites anchored on aniline-stacked graphene for the

hydrogen evolution reaction

Shenghua Ye, Feiyan Luo, Qianling Zhang, Pingyu Zhang, Tingting Xu, Qi Wang, Dongsheng He, Licheng Guo,

Yu Zhang, Chuanxin He, Xiaoping Ouyang, Meng Gu,* Jianhong Liu* and Xueliang Sun*

ContentsTable and Figures

Table S1 EXAFS fitting parameters for the Pt L3-edges of the Pt SASs/AG and Pt/C.

Table S2 EXAFS fitting parameters for the Pt L3-edges of the Pt SASs/AG before and after durability testing.

Figure S1 TEM and Raman spectra of graphene.

Figure S2 XPS spectra of survey, C 1s, O 1s and N 1s of graphene.

Figure S3 Water contact angle of graphene and aniline stacking graphene.

Figure S4 Photos of graphene-water suspension and aniline stacking graphene solution.

Figure S5 TEM, HRTEM, and elemental mapping images of AG.

Figure S6 XRD patterns of Pt SASs/AG and Pt/C.

Figure S7 XPS spectra of survey, C 1s, O 1s, and N 1s of AG.

Figure S8 XPS spectra of survey, C 1s, O 1s,and N 1s of Pt SASs/AG.

Figure S9 XPS spectra of survey, C 1s, O 1s, N 1s, Pt 4f and Cl 2p of Pt SASs/AG before microwave irradiation.

Figure S10 Extended XAFS spectra of Pt SASs/AG, Pt/C, and Pt foil.

Figure S11 LSV curves of Pt SASs/AG prepared by different volumes of H2PtCl6 solution.

Figure S12 LSV curves of Pt SASs/AG and Pt/C before and after iR correction.

Figure S13 TEM images of Pt/C before and after durability test.

Figure S14 TEM and AC HAADA-STEM images of Pt SASs/AG after durability test.

Figure S15 XANES and FT-EXAFS of the Pt L3-edge of Pt SASs/AG before and after durability testing (without phase

correction) and corresponding EXAFS fitting curve of Pt SASs/AG after durability testing.

Figure S16 HER performances of Pt SASs/AG and Pt/C in 1 M KOH solution.

Figure S17 DFT calculation models (side views) of Pt (111), Ptab/G and Pt SASs/AG.

Figure S18 Total DOS of Pt (111), Ptab/G and Pt SASs/AG.

Figure S19 Pt (111), Ptab/G and Pt SASs/AG with the H absorption model for the DFT calculations.

Electronic Supplementary Material (ESI) for Energy & Environmental Science.This journal is © The Royal Society of Chemistry 2019

TableTable S1. EXAFS fitting parameters for the Pt L3-edges of the Pt SASs/AG and Pt/C.

Sample path N R (Å) Σ/10−3Å2 ΔE0 (eV) R factor/10−3

Pt SASs/AG Pt–N 4.3 2.03 7.4 14.7 4.0Pt/C Pt–Pt 12.0 2.76 5.0 8.5 2.4

Table S2. EXAFS fitting parameters for the Pt L3-edges of the Pt SASs/AG before and after durability testing.Sample path N R (Å) Σ/10−3Å2 ΔE0 (eV) R factor/10−3

As-prepared Pt SASs/AG

Pt–N 4.3 2.03 7.4 14.7 4.0

Pt SASs/AG after durability test

Pt–N 4.5 2.03 7.4 14.7 4.0

Figures

1000 1500 2000 2500 3000

2D

G

Inte

nsity

/ a.

u.

Raman Shift / cm-1

D

(b)

Fig. S1 (a) TEM image, and (b) Raman spectrum of graphene.

The low ID/IG and intensive 2D peaks with narrow FWHM indicate that low defect and high quality of graphene.

0 200 400 600 800 1000 1200

Atomic%

C 98.31%O 1.69%

O 1s

Inen

sity

/ a.

u.

Binding Energy / eV

C 1s(a)

280 285 290 295

Inte

nsity

/ a.

u.

Binding energy / eV

(b) C=C 284.4 eV

525 530 535 540

Inte

nsity

/ a.

u.

Binding energy / eV

(c)

390 395 400 405 410

Inte

nsity

/ a.

u.

Binding energy / eV

(d)

Fig. S2 XPS spectra of (a) survey, (b) C1s, (c) O1s, and (d) N 1s of graphene

The oxygen in graphene is as low as 1.69 at%, and the binding energy of O 1s is located at ~532 eV, which suggests that the oxygen is originated from absorbed H2O on the surface. Moreover, the content of nitrogen is negligible from the spectra of survey and N 1s, indicates that the graphene is pure without doping of heteroatom.

Fig. S3 Water-contact angle of (a) graphene and (b) aniline-stacked graphene.

Fig. S4 Photos of (a) graphene–water suspension and (b) aniline-stacked graphene dispersion.

Fig. S5 (a) TEM, (b) HRTEM images, and (c) elemental mapping images of C and N of AG.

(a) (b)

30 40 50 60 70 80 90

(222)(311)(220)

(200)

2 theta / deg

Pt SASs/AG Pt/C

(111)

Fig. S6 XRD patterns of Pt SASs/AG and Pt/C (PDF#65-2868).

0 200 400 600 800 100012001400

Inte

nsity

/ a.

u.

Binding Energy / eV

C 1s

N 1sO 1s

(a)

280 285 290 295

In

tens

ity /

a.u.

Binding Energy / eV

C=C284.4 eV

Π–Π*

(b)

525 530 535 540

Inte

nsity

/ a.

u.

Binding Energy / eV

532.6 eV

(c)

390 395 400 405 410

Inte

nsity

/ a.

u.

Binding Energy / eV

(d)~399.5 eV

Fig. S7 XPS spectra of (a) survey, (b) C1s, (c) O1s, and (d) N 1s of AG.

0 200 400 600 800 100012001400

Pt 4f

N 1s

In

tens

ity /

a.u.

Binding Energy / eV

(a) C 1s

O 1s

280 285 290 295

Inte

nsity

/ a.

u.

Binding Energy / eV

C=C284.4 eV

Π–Π*

(b)

525 530 535 540

Inte

nsity

/ a.

u.

Binding Energy / eV

532.4 eV(c)

390 395 400 405 410

Inte

nsity

/ a.

u.

Binding Energy / eV

~399.4 eV(d)

Fig. S8 XPS spectra of (a) survey, (b) C1s, (c) O1s and (d) N 1s of Pt SASs/AG.

0 200 400 600 800 100012001400

Cl 2pPt 4f

O 1s

N 1s

Inte

nsity

/ a.

u.

Binding energy / eV

C 1s(a)

280 285 290 295

Inte

nsity

/ a.

u.

Binding energy / eV

(b) C=C284.4 eV

525 530 535 540

Inte

nsity

/ a.

u.

Binding energy / eV

(c)

390 395 400 405 410

Inte

nsity

/ a.

u.

Binding energy / eV

~399.5 eV

(d)

65 70 75 80 85

Inte

nsity

/ a.

u.

Binding energy / eV

(e)

~72.8 eV

190 195 200 205 210

Inte

nsity

/ a.

u.

Binding energy / eV

(f)

Fig. S9 XPS spectra of (a) survey, (b) C1s, (c) O1s, (d) N 1s, (e) Pt 4f and (f) Cl 2p of Pt SASs/AG before microwave irradiation.

0 2 4 6 8 10

-20

-10

0

10

20

R / A

Pt SASs/AG Pt/C

o

Fig. S10 Extended XAFS spectra of Pt SASs/AG and Pt/C.

-0.4 -0.3 -0.2 -0.1 0.0-30

-25

-20

-15

-10

-5

0

Curre

nt d

ensi

ty /

mA

cm-2 ge

o

Potential / V vs RHE

0.3 mL 0.5 mL 0.7 mL 1.0 mL 2.0 mL 5.0 mL

Fig. S11 LSV curves of Pt SASs/AG prepared by different volumes of H2PtCl6 solution with iR corrction.

-0.4 -0.3 -0.2 -0.1 0.0-50

-40

-30

-20

-10

0

Cu

rrent

den

sity

/ m

A cm

-2 geo

Potential / V vs RHE

Pt SASs/AG Pt/C

(a)

-0.4 -0.3 -0.2 -0.1 0.0-50

-40

-30

-20

-10

0

Curre

nt d

ensi

ty /

mA

cm-1 ge

o

Potential / V vs RHE

without iR correction with iR correction

(b)

-0.4 -0.3 -0.2 -0.1 0.0-50

-40

-30

-20

-10

0

Curre

nt d

ensi

ty /

mA

cm-2 ge

o

Potential / V vs RHE

without iR correction with iR correction

(c)

Fig. S12 (a) LSV curves of Pt SASs/AG and Pt/C before the iR correction; LSV curves of (b) Pt SASs/AG, and (c) Pt/C before and after the iR correction.

Fig. S13 TEM images of Pt/C (a) before and (b) after durability testing.

Fig. S14 (a) TEM image, (b) HAADA-STEM images and corresponding elemental mapping of (c-f) C, N, Pt and (g) AC HAADA-STEM images of Pt SASs/AG after durability testing.

11550 11600 11650 11700 11750

0.0

0.4

0.8

1.2

1.6

2.0In

tens

ity /

a.u.

Energy / eV

as-prepared after durability testing

(a)

0 2 4 6 8 10o

R / A

FT

/ k3

(k)

/ a.

u.

as-prepared after durabilty testing

o

(b)

0 2 4 6 8 10o

FT

/ k3

(k)

/ a.

u.

R / A

after durability testing fitting

(c)

Fig. S15 (a) XANES and (b) FT-EXAFS of the Pt L3-edge of Pt SASs/AG before and after durability testing (without phase correction); (c) Corresponding EXAFS fitting curve of Pt SASs/AG after durability testing.

-0.30 -0.25 -0.20 -0.15 -0.10 -0.05 0.00-50

-40

-30

-20

-10

0

Cur

rent

den

sity

/ m

A c

m-2

Potential / V vs RHE

Pt SASs/AG Pt/C

(a)

-0.30 -0.25 -0.20 -0.15 -0.10 -0.05 0.00-30

-25

-20

-15

-10

-5

0

Cur

rent

den

sity

/ m

A m

g-1

Potential / V vs RHE

Pt SASs/AG Pt/C

(b)

0.6 0.8 1.0 1.2 1.40

5

10

15

20

25

30

Tafel slope: 29.14 mV/decj0: 2.844 mA/cm-2

Pt SASs/AG Pt/C

Ove

rpot

entia

l / m

V

log(i / mA cm-2)

(c)

Tafel slope: 30.57 mV/decj0: 5.978 mA/cm-2

Fig. S16 LSV curves of Pt SASs/AG and Pt/C with current density normalized to the (a) geometry area and (b) mass of Pt in 1 M KOH at 2 mV s-1 respectively; (c) Tafel plots of Pt SASs/AG and Pt/C in 1 M KOH

Fig. S17 DFT calculation models (side views) of (a) Pt (111), (b) Ptab/G and (c) Pt SASs/AG.

-10 -8 -6 -4 -2 0 2 40.0

0.5

1.0

1.5

2.0

2.5

3.0DO

S / a

.u.

E-EF / eV

Total DOS Pt-4d Pt-4p Pt-5s

(a)

Fermi level

-20 -16 -12 -8 -4 0 40

1020304050607080

DOS

/ a.u

.

E-EF / eV

Total DOS Pt-4d Pt-4p Pt-5s C-2s C-2p

(b)

Fermi level

-20 -16 -12 -8 -4 0 40

20

40

60

80

100

120

DOS

/ a.u

.

E-EF / eV

Total DOS Pt-4d Pt-4p Pt-5s C-2s C-2p N-2s N-2p H-1s

(c)

Fermi level

Fig. S18 Total DOS of (a) Pt (111), (b) Ptab/G and (c) Pt SASs/AG.

Fig. S19 (a, d) Pt (111), (b. e) Ptab/G and (c,f) Pt SASs/AG with the H absorption modelfor the DFT calculations.