Iron-Carbon Hybrid Magnetic Nanosheets for Adsorption-Removal of Organic Dyes and 4-Nitrophenol from Aqueous SolutionSai Rashmi Manippady,

s-1

Supporting Information

Iron-Carbon Hybrid Magnetic Nanosheets for Adsorption-Removal of Organic Dyes and 4- Nitrophenol from Aqueous Solution

Sai Rashmi Manippady,

^†

Ashish Singh,

^#‡

Bhavya Moodalegowda Basavaraja,

^#†

Akshaya Kumar Samal,

^†

Sachchidanand Srivastava,

^||

Manav Saxena*

^†

AUTHOR ADDRESS

†

Centre for Nano and Material Sciences, Jain University, Ramanagaram, Bangalore-562112, Karnataka, India.

‡

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208016, Uttar Pradesh, India

||

Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore-560012, Karnataka, India.

#

These authors (AS and BMB) contributed equally.

Corresponding author: manavsaxena19@gmail.com, s.manav@jainuniversity.ac.in (MS)

S. No. Table of contents Page no.

Table S1 Different dye removal techniques s-3

Figure S1 EDS analysis of (a) CF-0, (b) CF-2. s-4

Figure S2 X-ray photoelectron spectroscopy (XPS) survey spectra of CF-0 and CF-2 s-5

Table S2 Magnetic properties of CF-0 and CF-2. s-6

Table S3 pH dependent Zeta potential study s-7

Figure S3 Zeta potential measurement of CF-2 (a) pH 2, (b) pH 3, (c) pH 5, (d) pH 7, (e)

pH 8, (f) pH 10, (g) pH of zero point charge s-8

Figure S4

(a) Dye adsorption efficiency of CF-0 and CF-2 at t=24 min for 50 mgL^-1 MB (pH 8) and CR (pH 2), (b) Dosage study for CF-2 at t=24 min with 50 mgL^-1 MB,

s-9

Figure S5 UV-Vis absorbance spectra for the adsorption of (a) MB by CF-2 at pH: 8 (b)

CR by CF-2 at pH: 2 and (c) CR by CF-2 pH: 7 s-10

Figure S6

(a) UV-Vis absorbance spectra for the adsorption of MB by CF-0, (b) Percent removal, (c) Effect of contact time on adsorption capacity of MB (d) Pseudo- first-order (e) Pseudo-second-order kinetics (f) Intraparticle diffusion model of MB

s-11

Figure S7

(a) Effect of pH on MB dye adsorption, (b) Effect of contact time on CF-2 adsorption capacity with 50 mg L^-1 MB, (c) Pseudo-first-order (d) ) Freundlich isotherm for MB.

s-12

Figure S8

(a) UV-Vis absorbance spectra for the adsorption of CR by CF-0, (b) Percent removal, (c) Effect of contact time on adsorption capacity of CR (d) Pseudo- first-order (e) Pseudo-second-order kinetics (f) Intraparticle diffusion model of CR

s-13

Figure S9

(a) Effect of pH on CR dye adsorption, (b) Effect of contact time on CF-2 adsorption capacity with 50 mg L^-1 CR, (c) Pseudo-first-order (d) ) Langmuir isotherm for CR.

s-14 Figure S10 Comparative intraparticle diffusion of MB and CR. s-15 Figure S11 Optical images of (a) Recovered adsorbent. Recovery process of (b) MB (c)

CR and (d) N₂ adsorption-desorption study of CF-2 after MB adsorption. s-16 Figure S12 Comparative UV-Vis spectroscopic study of standard and recovered (a) MB

and (b) CR using CF-2. s-17

Figure S13

(a) Collected Rhodamine based textile dye “suti gulabi” after centrifuge (b) UV-Visible spectra for the textile waste water before and after adsorption (inset: photograph of dye before and after adsorption).

s-18 Figure S14 (a) Effect of pH on hair dye adsorption, (b) UV-Vis absorbance spectra of hair

dye waste. s-19

Figure S15 (a) UV-Vis absorbance spectra for 50ppm 4-NP (b) Pseudo-first-order (c) Freundlich isotherm model and (d) Recovered 4-NP with methanol s-20 Figure S16 FESEM image of CF-2 (a) as synthesized (b) recovered after 5^th cycle (c)

PXRD of as synthesized and reused CF-2. s-21

Table S4 Comparative study of the adsorption parameters & performance of other s-22-

s-3

Table S1: Different dye removal techniques.

Dye removal technique Ref.

Adsorption

¹

Photocatalytic degradation

²

Membrane filtration

³

Osmosis

⁴

Coagulation and flocculation

⁵

Ion exchange

⁶

Irradiation

⁷

Figure. S1. EDS analysis of (a) CF-0, (b) CF-2.

(a)

(b)

s-5

FigureS2. X-ray photoelectron spectroscopy (XPS)-survey spectra of CF-0 and CF-2

Table S2. Magnetic properties of CF-0 and CF-2.

Adsorbent M

s

(emu g

^-1

) M

r

(emu g

^-1

) H

c

(Oe) M

r

/M

s

CF-0 0.01 0.0002 195 0.02

CF-2 19.52 3.65 423 0.19

s-7

Table S3. pH dependent mean zeta potential of CF-2

Sample pH Mean zeta potential (mV)

2 25.3

3 18.7

5 -8.4

7 -22.4

8 -24.4

CF-2

10 -32.5

FigureS3. Zeta potential measurement of CF-2 (a) pH 2, (b) pH 3, (c) pH 5, (d) pH 7, (e) pH 8,

(f) pH 10 (g) pH of zero-point charge

s-9

Figure S4. (a) Dye adsorption efficiency of CF-0 and CF-2 at t=24 min for 50 mgL

^-1

MB (pH 8)

and CR (pH 2), (b) Dosage study for CF-2 at t=24 min with 50 mgL

^-1

MB,

Figure S5. UV-Vis absorbance spectra for the adsorption of (a) MB at pH: 8 (b) CR at pH: 2 and

(c) pH: 7 by CF-2.

s-11

Figure S6. (a) UV-Vis absorbance spectra for the adsorption of MB by CF-0, (b) percent

removal, (c) effect of contact time on adsorption capacity of MB on control (d) Pseudo-first-

order (R

²

: 0.601) (e) pseudo-second-order kinetics (R

²

: 0.999) (f) Intraparticle diffusion model

of MB on control (R

²

: 0.625, R

²

: 0.392).

Figure S7.

(a) Effect of pH on MB dye adsorption, (b) Effect of contact time on CF-2 adsorption capacity with 50 mg L^-1 MB, (c) Pseudo-first-order (d) Freundlich isotherm for MB.

s-13

Figure S8. (a) UV-Vis absorbance spectra for the adsorption of CR by CF-0, (b) percent removal, (c) effect of contact time on adsorption capacity of CR on control (d) Pseudo-first-order (R

²

:0.917) (e) pseudo-second-order kinetics (R

²

: 0.978) (f) Intraparticle diffusion model of CR on control (R

²

:0.928, R

²

:0.719), contact time:32 min, adsorbent dosage: 6 mg, dye concentration:

50 mg L

^-1

and pH: 2.

Figure S9.

(a) Effect of pH on CR dye adsorption, (b) Effect of contact time on CF-2 adsorption capacity with 50 mg L^-1 CR, (c) Pseudo-first-order (d) Langmuir isotherm for CR.

s-15

Figure S10.

Comparative intraparticle diffusion of MB and CR.

Figure S11. Optical images of (a) Recovered adsorbent. Recovery process of (b) MB (c) CR and

(d) N

2

adsorption-desorption study of CF-2 after MB adsorption.

s-17

Figure S12. Comparative UV-Vis spectroscopic study of standard and recovered (a) MB and (b)

CR using CF-2.

Figure S13. (a) Collected Rhodamine based textile dye “suti gulabi” after centrifuge (b) UV- Visible spectra for the textile waste water before and after adsorption (inset: photograph of dye before and after adsorption).

Textile waste water: The waste dye effluent of textile coloring industry locally known as “suti

gulabi” a rhodamine-based dye was collected from Kanpur, Uttar Pradesh, India. The collected

effluent was centrifuged to remove any dispersed fibers and supernatant was collected for the

study (Figure S12a). Initial absorbance of the effluent was measured using UV-Vis

spectrophotometer. The adsorption study of effluent with CF-2 was performed at normal lab

conditions at STP. As collected effluent showed absorbance maximum at 540 nm and pink in

color. Upon addition of CF-2, the pink color disappeared and the absorbance intensity decreased

drastically (inset, Figure S12b). The absorbance study suggested that CF-2 could adsorb effluent

upto 90.2% in just 10 sec (Figure S12b) and the used adsorbent could be easily recovered upon

s-19

Figure S14. (a) Effect of pH on hair dye adsorption, (b) UV-Vis absorbance spectra of hair dye

waste.

Figure S15. (a) UV-Vis absorbance spectra for 50 ppm 4-NP (without AcOH) (b) Pseudo-first-

order (c) Freundlich isotherm model and (d) Normalized UV-Vis spectra for standard and

recovered 4-NP in methanol.

s-21

Figure S16: FESEM image of CF-2 (a) as synthesized (b) recovered after 5

^th

cycle (c) PXRD of

as synthesized and reused CF-2.

Table S4. Comparative study of the adsorption parameters & performance of other adsorbents.

Adsorbent

Adsorption capacity (mg g

-1

) Adsorbent wt. per dye volume (mg/mL) Time (min) Removal %

Ref.

Methylene Blue dye

CNTs/Fe@C 132.6 1.00 80 ~100 8

PB@PVP/rGO 44.7 1.00 10 99.6 9

NF/CF-BYs 141.8 3.33 120 >90 10

Fe

₃

O

₄

@C 52.6 1.00 2160 97.8 11

magnetite/silica/pectinNPs 197.2 2.00 150 82 12

Fe

3

O

4

@PPy/RGO 270.3 0.33 60 ~55 13

CoFe

2

O

4

/rGO composites 93.5 0.20 30 98.6 14

Fe

3

O

4

/montmorillonite nanocomposite

106.4 2.50 25 99.4 15

C/Fe

3C/γ-Fe2

O

3

185.2 0.40 24 99.9 This work

Congo Red Dye

α-Fe2

O

3

nanocrystals 161 0.60 180 97 16

CoFe

2

O

4

/rGO composite 104.5 0.25 30 86.4 14

Fe(OH)

₃

@cellulose PHFs 689.6 - 6000 >99 17

s-23

pTSA-Pani@GO-CNT 66.7 1.00 300 96.0 20

Aerogels from corn stalks 549 - 60 ~89 21

C/Fe

3C/γ-Fe2

O

3

531.9 0.40 24 96.6 This work

4-Nitrophenol

Fe

3

O

4

-graphene-oxysilane 142 0.5 5 ~75 22

Acid activated carbon 234 2.4 2880 68.4 23

Amine-Al-MOF 192.6 6.0 300 - 24

C/Fe

3C/γ-Fe2

O

3

109.1 1.0 24 99.5 This work

Table S5. Kinetic parameters of pseudo-first order and pseudo-second order and intraparticle diffusion model calculated using linear fits for the adsorption of MB and CR on CF-2. Isothermal parameters of the Langmuir and Freundlich model calculated using linear fits for the adsorption of MB and CR on CF-2.

Kinetic Study

Pseudo-first order Pseudo-second order

q

e(exp)

K

1

q

e(cal)

K

2

q

e(cal)

Dye mg.g

^-1

min

^-1

R

²

mg.g

^-1

g/mg/min R

²

mg.g

^-1

MB 127.34 0.88 0.943 30338.9 0.0245 0.999 142.85

CR 116.02 0.396 0.799 39174.2 0.0079 0.991 115.60

4-NP 49.78 0.638 0.883 386.2 0.206 0.999 49.90

Intraparticle Diffusion

K

p1

R

²

C

1

K

p2

R

²

C

2

Dye mg.g min

-1

mg.g

^-1

mg.g min

^-1

mg.g

^-1

MB 4.028 0.872 109.38 - - -

CR 9.902 0.937 66.18 - - -

4-NP 0718 0.998 46.81 0.066 0.998 49.422

Isotherm study

Langmuir isotherm Freundlich isotherm

Dye K

L

(L/mg)

q

max

(mg/g) R

L

R

²

K

F

(mg/g) n R

²

MB 0.108 185.2 0.156-0.035 0.950 0.698 8.465 0.704

CR 0.057 531.9 0.258-0.065 0.916 0.544 1.925 0.993

4-NP 0.407 109.1 0.046-0.013 0.985 0.581 7.606 0.977

s-25

References

(1) Han, L.-J.; Ge, F.-Y.; Sun, G.-H.; Gao, X.-J.; Zheng, H.-G. Effective Adsorption of Congo Red by a MOF-Based Magnetic Material. Dalton Trans 2019, 48, 4650-4656.

(2) Bhati, A.; Anand, S. R.; Gunture; Garg, A. K.; Khare, P.; Sonkar, S. K. Sunlight-Induced Photocatalytic Degradation of Pollutant Dye by Highly Fluorescent Red-Emitting Mg-N-Embedded Carbon Dots. ACS Sustain. Chem. Eng. 2018, 6, 9246-9256.

(3) Zhang, Y.; Yu, W.; Li, R.; Xu, Y.; Shen, L.; Lin, H.; Liao, B.-Q.; Wu, G. Novel Conductive Membranes Breaking Through the Selectivity-Permeability Trade-Off for Congo Red Removal. Sep.

Purif. Technol. 2019, 211, 368-376.

(4) Li, F.; Xia, Q.; Gao, Y.; Cheng, Q.; Ding, L.; Yang, B.; Tian, Q.; Ma, C.; Sand, W.; Liu, Y. Anaerobic Biodegradation and Decolorization of a Refractory Acid Dye by a Forward Osmosis Membrane Bioreactor. Environ. Sci. Water Res. Technol. 2018, 4, 272-280.

(5) Wei, T.; Wu, L.; Yu, F.; Lv, Y.; Chen, L.; Shi, Y.; Dai, B. pH-Responsive Chitosan-Based Flocculant for Precise Dye Flocculation Control and the Recycling of Textile Dyeing Effluents. RSC Adv. 2018, 8, 39334-39340.

(6) Almoisheer, N.; Alseroury, F. A.; Kumar, R.; Aslam, M.; Barakat, M. A. Adsorption and Anion Exchange Insight of Indigo Carmine onto Cual-LDH/Swcnts Nanocomposite: Kinetic, Thermodynamic and Isotherm Analysis. RSC Adv. 2019, 9, 560-568.

(7) Senasu, T.; Hemavibool, K.; Nanan, S. Hydrothermally Grown CdS Nanoparticles for Photodegradation of Anionic Azo Dyes Under UV-Visible Light Irradiation. RSC Adv. 2018, 8, 22592- 22605.

(8) Ma, J.; Ma, Y.; Yu, F. A Novel One-Pot Route for Large-Scale Synthesis of Novel Magnetic CNTs/Fe@C Hybrids and Their Applications for Binary Dye Removal. ACS Sustain. Chem. Eng. 2018, 6, 8178-8191.

(9) Lee, I.; Kang, S.-M.; Jang, S.-C.; Lee, G.-W.; Shim, H. E.; Rethinasabapathy, M.; Roh, C.; Huh, Y. S.

One-Pot Gamma Ray-Induced Green Synthesis of a Prussian Blue-Laden Polyvinylpyrrolidone/Reduced Graphene Oxide Aerogel for the Removal of Hazardous Pollutants. J. Mater. Chem. A 2019, 7, 1737- 1748.

(10) Du, Z.; Zhang, Y.; Li, Z.; Chen, H.; Wang, Y.; Wang, G.; Zou, P.; Chen, H.; Zhang, Y. Facile One- Pot Fabrication of Nano-Fe3O4/Carboxyl-Functionalized Baker’s Yeast Composites and Their Application in Methylene Blue Dye Adsorption. Appl. Surf. Sci. 2017, 392, 312-320.

(11) Cho, D.-W.; Lee, J.; Ok, Y. S.; Kwon, E. E.; Song, H. Fabrication of a Novel Magnetic Carbon Nanocomposite Adsorbent via Pyrolysis of Sugar. Chemosphere 2016, 163, 305-312.

(12) Attallah, O. A.; Al-Ghobashy, M. A.; Nebsen, M.; Salem, M. Y. Removal of Cationic and Anionic Dyes from Aqueous Solution with Magnetite/Pectin and Magnetite/Silica/Pectin Hybrid Nanocomposites:

Kinetic, Isotherm and Mechanism Analysis. RSC Adv. 2016, 6, 11461-11480.

(13) Bai, L.; Li, Z.; Zhang, Y.; Wang, T.; Lu, R.; Zhou, W.; Gao, H.; Zhang, S. Synthesis of Water- Dispersible Graphene-Modified Magnetic Polypyrrole Nanocomposite and its Ability to Efficiently Adsorb Methylene Blue from Aqueous Solution. Chem. Eng. J. 2015, 279, 757-766.

(14) Yin, W.; Hao, S.; Cao, H. Solvothermal Synthesis of Magnetic CoFe₂O₄/RGO Nanocomposites for Highly Efficient Dye Removal in Wastewater. RSC Adv. 2017, 7, 4062-4069.

(15) Chang, J.; Ma, J.; Ma, Q.; Zhang, D.; Qiao, N.; Hu, M.; Ma, H. Adsorption of Methylene Blue onto Fe₃O₄/Activated Montmorillonite Nanocomposite. Appl. Clay Sci. 2016, 119, 132-140.

(16) Wang, J.; Xu, L.; Zhang, Z.; Sun, P.-P.; Fang, M.; Liu, H.-K. Shape-Controlled Synthesis of α-Fe₂O₃ Nanocrystals for Efficient Adsorptive Removal of Congo Red. RSC Adv. 2015, 5, 49696-49702.

(17) Zhao, J.; Lu, Z.; He, X.; Zhang, X.; Li, Q.; Xia, T.; Zhang, W.; Lu, C. Fabrication and Characterization of Highly Porous Fe(OH)3@Cellulose Hybrid Fibers for Effective Removal of Congo Red from Contaminated Water. ACS Sustain. Chem. Eng. 2017, 5, 7723-7732.

(18) Hao, T.; Yang, C.; Rao, X.; Wang, J.; Niu, C.; Su, X. Facile Additive-Free Synthesis of Iron Oxide Nanoparticles for Efficient Adsorptive Removal of Congo Red and Cr(VI). Appl. Surf. Sci. 2014, 292, 174-180.

(19) Beyki, M. H.; Bayat, M.; Shemirani, F. Fabrication of Core–Shell Structured Magnetic Nanocellulose Base Polymeric Ionic Liquid for Effective Biosorption of Congo Red Dye. Bioresour.

Technol. 2016, 218, 326-334.

(20) Ansari, M. O.; Kumar, R.; Ansari, S. A.; Ansari, S. P.; Barakat, M. A.; Alshahrie, A.; Cho, M. H.

Anion Selective Ptsa Doped Polyaniline@Graphene Oxide-Multiwalled Carbon Nanotube Composite for Cr(VI) and Congo Red Adsorption. J. Colloid Interface Sci. 2017, 496, 407-415.

(21) Li, X.; Lu, X.; Yang, J.; Ju, Z.; Kang, Y.; Xu, J.; Zhang, S. A Facile Ionic Liquid Approach to Prepare Cellulose-Rich Aerogels Directly from Corn Stalks. Green Chem. 2019, 21, 2699-2708.

(22) Luo, J.; Gao, Y.; Tan, K.; Wei, W.; Liu, X. Preparation of a Magnetic Molecularly Imprinted Graphene Composite Highly Adsorbent for 4-Nitrophenol in Aqueous Medium. ACS Sustain. Chem. Eng.

2016, 4, 3316-3326.

s-27 (24) Liu, B.; Yang, F.; Zou, Y.; Peng, Y. Adsorption of Phenol and p-Nitrophenol from Aqueous Solutions on Metal–Organic Frameworks: Effect of Hydrogen Bonding. J. Chem. Eng. Data 2014, 59, 1476-1482.