Reversible CO2 adsorption by an activated nitrogen doped graphene/polyaniline material

K.Christian Kemp, Vimlesh Chandra, Muhammad Saleh and Kwang S.Kim*

Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science

and Technology, Pohang 790-784, Korea

Corresponding Author E-mail address: kim@postech.ac.kr

Synthesis and Characterization of Graphene Oxide.

Graphene oxide was synthesized according to Hummers method. [1] In brief, 2 g of graphite

(325 mesh Alpha Auser), 2 g of NaNO3 and 60 ml of H2SO4 were mixed and stirred at 0 °C for

30 minutes. 4 g KMnO4 was slowly added to the reaction mixture making sure the temperature

does not rise above 35 °C. The resulting solution was then stirred for 2 hours by removal from

the ice bath and heating it to 35 °C. 100 ml of distilled H2O was added to the reaction mixture

which resulted in a rapid increase in temperature to 98 °C and the solution was stirred for 15

minutes. The solution was subsequently diluted to 500 ml and 10 ml H2O2 was added. The

resulting solution was allowed to stir overnight before been centrifuged (13000 rpm, 20 minutes)

and washed with 10 % HCl. The precipitate was thereafter washed with distilled H2O repeatedly

until a neutral pH was observed.

Figure S1. a) Raman spectrum, b) FTIR spectrum, c) XRD spectrum, d) SEM image and e) AFM

image showing a line profile of GO.

Figure S2. Infrared spectra of samples NG0 to NG8.

(b)(a)

(e)

(c)

(d)

Figure S3. Raman spectra of samples NG0 to NG8.

Figure S4. XRD spectra of samples NG0 to NG8.

Table S1. Elemental analysis and XPS elemental analysis for the samples NG0 to NG8

Sample Analysis Method N% C% H% O%1

NG0 Elemental 12.787 71.12 4.508 11.6

Elemental 11.876 70.29 4.331 13.5

Average 12.332 70.705 12.6

XPS 10.58 80.80 7.69

NG4 Elemental 6.439 78.84 0.973 13.7

Elemental 10.329 75.399 4.128 10.1

Average 8.384 77.12 11.9

XPS 4.39 82.34 13.26

NG5 Elemental 9.477 75.65 3.224 11.6

Elemental 10.569 75.49 3.196 10.7

Average 10.023 75.57 11.2

XPS 7.58 82.96 9.32

NG6 Elemental 8.342 74.08 2.780 14.8

Elemental 7.747 73.77 2.791 15.7

Average 8.045 73.93 15.3

XPS 6.56 83.79 9.08

NG7 Elemental 3.972 76.87 3.068 16.1

Elemental 3.770 78.10 3.218 14.9

Average 3.871 77.49 15.5

XPS 4.19 84.69 10.07

NG8 Elemental 1.485 78.75 2.769 17.0

Elemental 1.350 77.98 2.482 18.2

Average 1.418 78.37 17.6

XPS 2.05 80.99 14.60

1) O2 content calculated using the available elemental analysis data.

Figure S5. XPS full spectrum survey for NG0 to NG8.

Figure S6. C1s core spectra for samples NG0 to NG8.

Figure S7. XPS data for a) NG4 and b) NG6.

Figure S8. N2 adsorption isotherms for samples NG0 to NG8

Figure S9. Mesopore distribution plots calculated using DH method for samples NG0 to NG8.

Figure S10.CO2 adsorption isotherms for the NG4 and NG7 samples at 273 K.

Figure S11. Correlation graphs showing the relationships between adsorption capacity and a)

pore volume, b) micropore volume, c) BET surface area and d) nitrogen content.

Figure S12. Isoteric heat of adsorption for NG7.

Figure S13. Isoteric Heat of adsorption for NG4.

Figure S14. Initial slopes calculated for NG7 selective adsorption.

References

1. Hummers W S and Offeman R E 1958 J.Am.Chem.Soc. 80, 1339.