Electronic Supplementary Information

Oxygen-containing/amino-group bi-functionalized SBA-15 towards efficient removal of methylene blue: Kinetics, isotherm and mechanism analysis

Wen-Jing Qiao · Zhen-Zhen Wang · Shang-Ru Zhai · Zuo-Yi Xiao · Feng Zhang · Qing-Da An

W. Qiao · Z. Wang · S. Zhai (*) · Z. Xiao · F. Zhang · Q. An (*) Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian116034, China e-mail: zhai sr @dlpu.edu.cn; [email protected]

0 . 0 3 0 . 4 5 (a) (b) 20oC o 0 . 4 0 20 C 25oC o 25oC 0 . 3 5 30 C 0 . 0 2 o 30 C 0 . 3 0

0 . 2 5 e e q

/ q e /

e

C 0 . 2 0 C 0 . 0 1 2 0 . 1 5 r1=0.9960 2 r1=0.9988 2 r =0.9991 0 . 1 0 2 2 r2=0.9991 2 r =0.9988 0 . 0 5 2 3 r3=0.9896 0 . 0 0 0 . 0 0 0 1 2 3 4 5 0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0

Ce(mg/L) Ce(mg/L)

0 . 3 6 0 . 3 5

(d) (c) 0 . 3 0 0 . 3 0 o 0 20 C 20 C 0 . 2 5 o 250C 25 C 0 . 2 4 o 300C 0 . 2 0 30 C e 0 . 1 8 e 0 . 1 5 q q

/

/ e e C C 2 0 . 1 0 0 . 1 2 r1=0.9996 2 r1=0.9997 2 0 . 0 5 r2=0.9999 2 0 . 0 6 r2=0.9999 2 0 . 0 0 r3=0.9999 2 r3=0.9999 0 . 0 0 - 0 . 0 5 0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 - 2 0 0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 1 4 0 1 6 0 Ce(mg/L) Ce(mg/L)

0 . 3 5 (e) 0 . 3 0 o 20 C 0 . 2 5 o 25 C o 0 . 2 0 30 C e q

/ 0 . 1 5 e C

0 . 1 0 2 r1=0.9995 2 0 . 0 5 r2=0.9999 2 0 . 0 0 r3=0.9998

0 2 0 4 0 6 0 8 0 1 0 0 1 2 0 Ce(mg/L)

Fig. S1. Linear Langmuir isotherm graph: (a) SBA-15, (b) C-SBA15-ox, (c) NH2-

2.5%-SBA15-ox, (d) NH2-5%-SBA15-ox, and (e) NH2-10%-SBA15-ox.

2 . 3 2 . 7 (a) 2 . 2 (b) o 2 . 6 20 C o 20 C 2 . 1 (a) o 2 . 5 o 25 C 25 C 2 . 0 o o 30 C 2 . 4 30 C

) 1 . 9 2 . 3 e ) e q

( q

( g 2 . 2 g o 1 . 8 l o l 2 2 . 1 1 . 7 r =0.9552 2 1 r1=0.8767 2 2 . 0 2 1 . 6 r2=0.8949 r2=0.8960 2 1 . 9 2 1 . 5 r3=0.8767 r3=0.9575 1 . 8 - 2 . 0 - 1 . 5 - 1 . 0 - 0 . 5 0 . 0 0 . 5 1 . 0 - 0 . 5 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 log(Ce) log(Ce)

2 . 7 2 . 7 (d) (c) o o 20 C 20 C o 2 . 6 o 2 . 6 25 C 25 C o o 30 C 30 C ) ) e 2 . 5 e 2 . 5 q q

( ( g g o o l l 2 2 r1=0.8558 r1=0.8228 2 . 4 2 2 . 4 2 r2=0.8483 r2=0.7846 2 2 r3=0.8899 r3=0.7659 2 . 3 2 . 3 - 0 . 5 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 - 0 . 5 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 log(Ce) log(Ce)

2 . 7 0 (e) 2 . 6 5 o 20 C o 2 . 6 0 25 C o 30 C 2 . 5 5 ) e q

(

g 2 . 5 0 o l 2 r =0.9160 2 . 4 5 1 2 r2=0.9001 2 . 4 0 2 r3=0.7929 2 . 3 5 - 0 . 5 0 . 0 0 . 5 1 . 0 1 . 5 2 . 0 2 . 5 log(Ce)

Fig. S2. Linear Freundlich isotherm graph: (a) SBA-15, (b) C-SBA15-ox, (c) NH2-

2.5%-SBA15-ox, (d) NH2-5%-SBA15-ox, and (e) NH2-10%-SBA15-ox.

0 . 0 8

C-SBA15-ox NH -2.5%-SBA15-ox 0 . 0 7 2 0 . 0 2 0 SBA15 NH2-5%-SBA15-ox 0 . 0 1 6 NH2-10%-SBA15-ox 0 . 0 6 0 . 0 1 2

L R 0 . 0 5 0 . 0 0 8

0 . 0 0 4 0 . 0 4 L

R 1 0 2 0 3 0 4 0 5 0 C0(mg/L) 0 . 0 3

0 . 0 2

0 . 0 1

0 . 0 0 5 0 1 0 0 1 5 0 2 0 0 2 5 0 3 0 0 3 5 0

C0(mg/L)

Fig. S3. RL versus C0 graphs for studied samples.

2 . 3 4 . 2 (b) (a) T=293K T=293K pH ~7 4 . 0 pH ~7 C =200mg/L 0 C0=200mg/L 2 . 2 2 3 . 8 r =0.9153 r2=0.9143

) ) 3 . 6 t t q q - - e e

q 2 . 1 q 3 . 4 （ （ n n I I

3 . 2

2 . 0 3 . 0

2 . 8 0 2 4 6 8 1 0 1 2 1 4 1 6 0 2 4 6 8 1 0 1 2 1 4 1 6 t (min) t (min)

3 . 8 (c) T=293K 3 . 0 (d) T=293K 3 . 6 pH ~7 pH ~7 C0=200mg/L 3 . 4 C0=200mg/L r2=0.9858 2 . 5 2 3 . 2 r =0.9298 ) ) t t q q -

3 . 0 -

e 2 . 0

e

q q （ （ n

2 . 8 n I I 1 . 5 2 . 6

2 . 4 1 . 0

2 . 2 0 2 4 6 8 1 0 1 2 1 4 1 6 0 2 4 6 8 1 0 1 2 1 4 1 6 t (min) t (min)

3 . 6 (e) T=293K 3 . 4 pH ~7 3 . 2 C0=200mg/L 2 3 . 0 r =0.9727 )

t 2 . 8 q - e

q 2 . 6 （ n I 2 . 4

2 . 2

2 . 0

1 . 8 0 2 4 6 8 1 0 1 2 1 4 1 6 t (min)

Fig. S4. Pseudo-first-order plot of the adsorption of MB onto prepared samples :(a)

SBA-15, (b) C-SBA15-ox, (c) NH2-2.5%-SBA15-ox, (d) NH2-5%-SBA15-ox, and (e)

NH2-10%-SBA15-ox.

0 . 1 0 0 . 0 5 (a) (b)

0 . 0 8 0 . 0 4

0 . 0 6 0 . 0 3 t t

q q / / t t 0 . 0 4 T=293K 0 . 0 2 T=293K pH ~7 pH ~7 C0=50mg/L 0 . 0 2 0 . 0 1 C0=200mg/L r2=0.9999 r2=0.9998

0 . 0 0 0 . 0 0 0 2 4 6 8 1 0 1 2 1 4 1 6 0 2 4 6 8 1 0 1 2 1 4 1 6 t (min) t (min)

0 . 0 4 0 . 0 4 (d) (c)

0 . 0 3 0 . 0 3

t 0 . 0 2

t 0 . 0 2

q q / / t T=293K t T=293K pH ~7 pH ~7 0 . 0 1 C0=50mg/L 0 . 0 1 C0=200mg/L 2 r =0.9998 r2=0.9999

0 . 0 0 0 . 0 0 0 2 4 6 8 1 0 1 2 1 4 1 6 0 2 4 6 8 1 0 1 2 1 4 1 6 t (min) t (min)

0 . 0 3 0 (e)

0 . 0 2 5

0 . 0 2 0

t 0 . 0 1 5

q / t

0 . 0 1 0 T=293K pH ~7 C =200mg/L 0 . 0 0 5 0 r2=0.9998

0 . 0 0 0 0 2 4 6 8 1 0 1 2 1 4 t (min)

Fig. S5. Pseudo-second-order plot of the adsorption of MB onto various samples: (a)

SBA-15, (b) C-SBA15-ox, (c) NH2-2.5%-SBA15-ox, (d) NH2-5%-SBA15-ox, and (e)

NH2-10%-SBA15-ox.

4 8 0

C-SBA15-ox NH -2.5%-SBA15-ox 2 4 6 0 NH -5%-SBA15-ox 2 NH -10%-SBA15-ox 2 4 4 0

4 2 0

) 4 0 0 g / g

m ( t 3 8 0 q

1 5 8 3 6 0 1 5 6

) 1 5 4 g / g 1 5 2 m

3 4 0 ( t

q 1 5 0

1 4 8 SBA15 3 2 0 0 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 t1/2(min1/2)

0 2 4 6 8 1 0 1/2 1/2 t (min ) Fig. S6. Intra-particle diffusion model of methylene blue adsorption over studied samples with varied surface chemistry. Table S1. Textural properties of studied samples.

2 -1 a 3 -1 Samples SBET(m g ) Vp (cm g ) DP(nm)

SBA15 623 0.85 7.89

C-SBA15-ox 589 0.78 6.06

NH2-2.5%-SBA15-ox 543 0.62 5.13

NH2-5%-SBA15-ox 511 0.59 4.90

NH2-10%-SBA15-ox 485 0.52 4.76 Table S2. Thermodynamic parameters of MB adsorption onto different samples. samples T(K) ΔG0 ΔH0 ΔS0 R2 (kJ/mol) (kJ/mol) (J/K mol) SBA15 293 -8.84 49.83 199.95 0.933 298 -9.57 303 -10.84 C-SBA15-ox 293 -4.56 40.60 159.15 0.902 298 -5.69 303 -6.23 NH2-2.5%- 293 -5.55 43.86 167.73 0.987 SBA15-ox 298 -6.50 303 -7.24 NH2-5%- 293 -5.69 43.88 168.80 0.985 SBA15-ox 298 -6.65 303 -7.38 NH2-10%- 293 -5.97 44.48 169.34 0.967 SBA15-ox 298 -6.92 303 -7.56