Page S1

Supporting Information

Influence of Surface Area, Porous Structure, and Surface State on the Supercapacitor Performance of Titanium Oxynitride: Implications for Nanostructuring Strategy

Eun Joo Lee,†,# Lanlee Lee,†,# Muhammad Awais Abbas,‡ and Jin Ho Bang*,†,‡,§

Department of Bionano Technology, Department of Advanced Materials Engineering, and Department

of Chemical and Molecular Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu,

Ansan, Gyeonggi-do 15588, Republic of Korea

AUTHOR INFORMATION

Corresponding Author: Jin Ho Bang

*Email: jbang@hanyang.ac.kr

† Department of Bionano Technology, Hanyang University

‡ Department of Advanced Materials Engineering, Hanyang University

§ Department of Chemical and Molecular Engineering, Hanyang University

# These authors contributed equally to this work.

Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics.This journal is © the Owner Societies 2017

Page S2

Figure S1. Time-resolved SEM images of h-TiOxN1-x at different NH3 annealing times.

Figure S2. SEM images of h-TiOxN1-x obtained after (A and B) 2 h and (C and D) 3 h of nitridation.

Page S3

Inte

nsity

(a.u

.)

2 Theta (Degree)

Inte

nsity

(a.u

.)

2 Theta (Degree)

h-TiOxN1-x (2h) h-TiOxN1-x (3h)

A B

(111)

(200)

(220)

(311

)(4

20)

(111)

(200)

(220)

(311

)(4

20)

20 30 40 50 60 70 80 20 30 40 50 60 70 80

C D

0 0.2 0.4 0.6 0.8 1.00

50

100

150

200

250

300

Volu

me

Adso

rbed

(cm

3 g-1

)

Relative Pressure (P/P0)

AdsorptionDesorption

1 10 1000

0.2

0.4

0.6

0.8

1.0

1.2

dV/d

logD

Pore Diameter (nm)

0 0.2 0.4 0.6 0.8 1.00

50100150200250300350400

Volu

me

Adso

rbed

(cm

3 g-1

)

Relative Pressure (P/P0)1 10 100

00.20.40.60.81.01.21.41.6

dV/d

logD

Pore Diameter (nm)

h-TiOxN1-x (2h) h-TiOxN1-x (2h)

E FAdsorptionDesorption

h-TiOxN1-x (3h) h-TiOxN1-x (3h)

Figure S3. XRD patterns of h-TiOxN1-x obtained after (A) 2 h and (B) 3 h of nitridation. N2

adsorption/desorption isotherms and the pore-size distribution of (C and D) h-TiOxN1 (2h) and (E and F)

h-TiOxN1 (3h). The BET surface areas of h-TiOxN1 (2h) and of h-TiOxN1 (3h) are 64.5 and 68.6 m2g-1

and their pore volumes are 0.461 and 0.549 cm3g-1, respectively. These increases in the surface area

and pore volume as compared to those of h-TiOxN1-x obtained after 1 h of nitridation result from the

partial collapse of the hexagonal secondary structure.

Page S4

Table S1. Lattice parameters of TiO and TiN taken from JCPDS database. The red-colored JCPDS

cards are the most commonly used ones in the literature. We too referred to these cards for the

identification of our materials.

TiO TiN

JCPDS card number Lattice parameter (Å) JCPDS card number Lattice parameter (Å)

04-004-9041 4.1705 04-002-0575 4.22603-065-9473 4.1705 01-087-0632 4.23401-089-5010 4.172 04-004-5181 4.23501-089-3660 4.1735 04-002-0166 4.23504-001-6834 4.174 01-074-8388 4.23504-004-8994 4.1766 04-002-6279 4.239900-008-0117 4.177 04-004-6867 4.2404-007-8198 4.177 04-003-1310 4.2404-006-1351 4.177 04-004-0779 4.24104-001-7607 4.178 04-003-1280 4.24104-006-6021 4.179 04-001-2272 4.24104-006-0746 4.18 00-038-1420 4.2417304-004-4098 4.18 04-002-6734 4.24204-002-5613 4.18 04-003-7146 4.24304-002-5455 4.18 01-087-0629 4.24404-002-0427 4.181 01-087-0628 4.24401-072-2741 4.184 01-071-9845 4.244204-002-5596 4.185 04-003-3767 4.24604-001-9372 4.185 04-002-2466 4.24904-002-5624 4.19 04-002-5535 4.2501-071-5272 4.2043 04-003-4495 4.2604-003-5563 4.22 03-065-0965 4.2701-072-4593 4.293 01-087-0631 4.32

Page S5

(111)d=2.42 Å

(200)d=2.10 Å

(220)d=1.48 Å

Figure S4. TEM images of h-TiOxN1-x at different magnifications.

294 292 290 288 286 284 282 2800

1000

2000

3000

4000

5000

6000

7000

8000

Inte

nsity

(a.u

.)

Binding Energy (eV)

C 1s

298 296 294 292 290 288 286 284 282 2800

1000

2000

3000

4000

5000

6000

7000

8000

C 1s

Inte

nsity

(a.u

.)

Binding Energy (eV)

K 2p

A B

Figure S5. XPS C 1s and K 2p spectra of n-TiOxN1-x taken (A) before and (B) after 2000 cycles of

potential sweep. The XPS measurements were carried out after thoroughly washing n-TiOxN1-x

electrode to remove any possible ion residues on the surface.

Page S6

20 30 40 50 60 70 80

Inte

nsity

(a.u

.)

2 Theta (Degree)20 30 40 50 60 70 80

Inte

nsity

(a.u

.)

2 Theta (Degree)

h-TiOxN1-x

(111)

(200)

(220)

(311

)(4

20)

n-TiOxN1-x

(111)

(200)

(220)

(311

)(4

20)

*

*

*

* ** *

A B

Figure S6. XRD patterns of (A) h-TiOxN1-x and (B) n-TiOxN1-x obtained after 2000 cycles of potential

sweep. Note that the peaks labelled by the black-colored asterisks refer to diffraction peaks from

carbon fiber paper used for an electrode substrate. Those by the red-colored asterisks are attributed to

K2Ti4O9 phase resulting from the corrosion of TiOxN1-x.

Figure S7. SEM images of (A) h-TiOxN1-x (small aggregated particles sporadically observed are

carbon additive (Super P) used for the preparation of electrode paste) and (B) n-TiOxN1-x obtained after

2000 cycles of potential sweep. It is somewhat difficult to specifically discern n-TiOxN1-x from the

mixture of n-TiOxN1-x and super P in the SEM image. However, given that the amount of n-TiOxN1-x

used for the electrode (80 wt%) and the absence of well-defined surface morphology (i.e., severely

deformed nanoparticle network) that are clearly visible in the SEM image of n-TiOxN1-x presented in

Figs. 4A and 4B, we infer that the structural collapse was more facilitated in the n-TiOxN1-x than in h-

TiOxN1-x.