Supporting Information For

Functionalization of biomass carbonaceous aerogels and its

application as electrode materials for electro-enhanced recovery of

metal ions

Jie Liab, Xiangxue Wanga, Hongqing Wangc, Suhua Wanga,d, Tasawar Hayatd, Ahmed

Alsaedid, and Xiangke Wangabcd*

a College of Environmental Science and Engineering, North China Electric Power University,

Beijing 102206, P. R. China.

b Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions,

School for Radiological and Interdisciplinary Sciences, Soochow University, Suzhou 215123, P. R.

China

c School of Chemistry and Chemical Engineering, University of South China, 28 Changsheng

West Road, Hengyang, Hunan 421001, P.R. China

d NAAM Research Group, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi

Arabia

* Corresponding author. Email: xkwang@ncepu.edu.cn or xkwang@ipp.ac.cn

Electronic Supplementary Material (ESI) for Environmental Science: Nano.This journal is © The Royal Society of Chemistry 2017

CDI decontamination test

The electrosorption capacity of the CDI system was conducted in a continuously

recycling system including a home-made single CDI unit, an electrical power supply,

a conductivity meter (Type 308A, Leici company), a peristaltic pump (BT100-2J,

Baoding LanGe constant Flow Pump Co., Ltd, China) and a water tank. In each

experiment, the CuCl2 solution was continuously pumped from the pump into the cell

and the effluent was returned to the water tank. In detail, the flow rate was set

constant to 25 mL/min and the total solution volume was 200 mL in the system. The

distance of 2 mm between the electrodes and a direct voltage were applied. The CDI

electrodes were prepared as following: 80 mg electrode materials with 10 mg carbon

black and 10 mg PTFE were dispersed into 5 mL ethanol solution under ultrasonic

treatment for 5 min to form dispersion. Then, this dispersion was dropped onto the

center of a nickel foam plate. After that, the resultant electrodes were dried at 140 °C

overnight. The hole with a diameter of 5 mm was punched in the prepared electrode to

allow the water flowing through the CDI device.

STEM C Ka

O Ka Ti Ka

Fig. S1 TEM mapping of the CAs/TiO2.

4000 3500 3000 2500 2000 1500 1000 500

CAs-Fe2O3

CAs-CeO2

CAs-TiO2

CAs

Wavenumber (cm-1)

Inten

sity

(a.u

.)

Fig. S2 FTIR spectra of CAs and CAs/MO hybrids.

0.0 0.2 0.4 0.6 0.8 1.0

0

20

40

60

80

100

120

Relative pressure (p/p0)

Qu

anity

adso

rbed

(cm

3 /g)

CAs/CeO2

CAs/Fe2O3

A

0 50 100 150 200 2500

40

80

120

160

200

240

CAs/Fe2O3

CAs/CeO2

Cum

ulati

ve su

rface

area

(m2 /g

)

Pore diameter (nm)

B

0.0 0.2 0.4 0.6 0.8 1.0

0

20

40

60

80

100

120

Relative pressure (p/p0)

Qu

anity

adso

rbed

(cm

3 /g)

CAs/CeO2

CAs/Fe2O3

A

0 50 100 150 200 2500

40

80

120

160

200

240

CAs/Fe2O3

CAs/CeO2

Cum

ulati

ve su

rface

area

(m2 /g

)

Pore diameter (nm)

B

Fig. S3 Nitrogen adsorption−desorption isotherms (A); and their corresponding

cumulative distribution curve (B) of the CAs/CeO2 and CAs/Fe2O3 hybrids.

(101)(101)(004)

(200)

CAs/TiO2

(102)(104)

CAs/Fe2O3 CAs/CeO2

(311)

(200)

(101)(101)(004)

(200)

CAs/TiO2

(101)(101)(004)

(200)

CAs/TiO2

(102)(104)

CAs/Fe2O3 CAs/CeO2

(311)

(200)

Fig. S4 The SAED patterns of the as-obtained CAs/MO hybrids.

50 nm50 nm

A B

50 nm50 nm50 nm50 nm

A B

Fig. S5 TEM images of the CAs/TiO2 hybrids with different added amount of Ti3+

precursor: 5 mg (A) and 15 mg (B) Ti3+ precursor in 15 mL aqueous solution

containing 30 mg of CAs.

0.0 0.2 0.4 0.6 0.8 1.0 1.2

-4

-2

0

2

4

Potential (V) vs Ag/AgCl

Spec

ific c

urre

nt (A

/g)

10 mg/L 50 mg/L 100 mg/L

Fig. S6 CAs/TiO2 electrodes in different CuCl2 concentrations at a scan rate of 20

mV/s.

CAs

CAs/TiO2

CAs/CeO2

CAs/Fe2O3

0.4 s 0.6 s 0.8 s 1.2 s

32o

25o

36o

38o

0o

0o

0o

0o

Fig. S7 Water contact angle measurements of the prepared electrodes.

Fig. S8 The actual CDI device.

Fig. S9 Cu(II) removal capacity and pH value of decontamination experiments for 50

mg/L CuCl2 solution at various applied potentials.

930 940 950 960

Open circuit

Cu 2p1/2 shakeup

Cu 2p1/2Cu 2p3/2 shakeup

Cu 2p3/2

Binding energy (eV)

Inten

sity

(a.u

.)

Cu 2p

1.2 V

Fig. S10 Cu 2p high resolution XPS spectra of the CAs/TiO2 electrodes after the

experiments at open circuit and applied voltage of 1.2 V.

0 40 80 120 160 200

10

20

30

40

50

60

70

C0 (mg/L)

Rem

oval

effic

iency

(%) CAs/TiO2

CAs/CeO2

CAs/Fe2O3

CAs CAs/TiO2, 0 V

Fig. S11 The removal efficiency of these electrodes with different initial

concentration of Cu(II).

0 20 40 60 80 1000

1

2

3

4

5

6

Curre

nt (m

A)

Time (min)

Fig. S12 Current transient curve for CAs/TiO2 in a 200 mg/L Cu(II) solution at 1.2 V.

The charge efficiency is obtained from the formula:1

F

in which is the deionization capacity (mol/g), F is the Faraday constant (96485

C/mol) and (charge, C/g) is calculated through integrating the current. Base on the

formula, the charge efficiency of CAs/TiO2 was calculated to be 0.44.

500 nm500 nm

Fig. S13 SEM image of the CAs/TiO2 hybrids after cycling three times.

Fig. S14 Underlying mechanism of the CDI process for Cu(II) removal in the

presence of NaCl.

Table S1 Parameters for Langmuir isotherm modelsCs max

(mg/g)b

(L/mg)R2

CAs/TiO2, 0 V 19.280 0.430 0.993

CAs, 1.2 V 30.353 0.309 966

CAs/Fe2O3, 1.2 V 41.424 0.268 0.996

CAs/CeO2, 1.2 V 49.281 0.238 0.990

CAs/TiO2, 1.2 V 57.134 0.337 0.989

Reference

1. X. Xu, Z. Sun, D. H. Chua and L. Pan, Sci. Rep., 2015, 5, 11225.