Analysis of graphene samples

Analysis of trace impurities with XRF (X-ray Fluorescence)

D. Lisovytskiy et.al., IChF PAN

1. Substrate – graphite powder, ACROS product

(XRF: X-ray fluorescence)

Cl(0.5%) > Fe(0.15%) > S(0.08%) = Ca(0.08%) > K(0.03%) > Cu(0.02%) > Ti(0.01%) > Ni(0.008%)

2. GO foil

S(2.5%) > Ca(1%) > Mn(0.5%) > K(0.3%) > Cl(0.08%) = Fe(0.08%) > Cu(0.2%) = Zn(0.02%) > Ni(0.007%) > Cr(0.006%)

3. rGO powder

Cl(0.3%) > Mn(0.2%) > S(0.01%) = K(0.01%) = Fe(0.01%) > Ca(0.009%) > Cu(0.006%) > Ni(0.001%)

C, H, N elemental analysis

G. Trykowski et.al., WCh UMK

Thermogravimetric analysis (TGA) for graphite, GO and rGO

G. Trykowski et.al., WCh UMK

Raman spectroscopy

M. Mazurkiewicz, A. Małolepszy et.al., WIM PW

Sample	D position	D FWHM	G position	G FWHM	ID/IG	D' position	ID'/IG	2D position	2D FWHM	I2D/IG
Graphite ACROS	1352	59	1580	21	0.20	1621	0.049	2686/2725	61/51	0.38
GO	1353	127	1560	70	1.87	1604	1.45	2701	178	0.22
RGO	1351	83	1582	63	1.48	1612	0.36	2714	199	0.22

(FWHM – full width at half maximum)

FTIR spectroscopy

M. Mazurkiewicz, A. Małolepszy et.al., WIM PW

XPS analysis ¹⁾

¹⁾ L. Stobinski, B. Lesiak, A. Małolepszy, M. Mazurkiewicz, B. Mierzwa, J. Zemek, P. Jiricek, I. Bieloshapka, Graphene oxide and reduced graphene oxide studied by the XRD, TEM and electron spectroscopy methods, Journal of Electron Spectroscopy and Related Phenomena, Vol. 195 (2014) pp. 145–154.

C and O atomic content in functional groups in GO, rGO and graphite by XPS ¹⁾

¹⁾ L. Stobinski, B. Lesiak, A. Małolepszy, M. Mazurkiewicz, B. Mierzwa, J. Zemek, P. Jiricek, I. Bieloshapka, Graphene oxide and reduced graphene oxide studied by the XRD, TEM and electron spectroscopy methods, Journal of Electron Spectroscopy and Related Phenomena, Vol. 195 (2014) pp. 145–154.

XRD analysis ¹⁾

The 002 plane belongs to graphite powder (2Θ = 26.5 deg)

¹⁾ L. Stobinski, B. Lesiak, A. Małolepszy, M. Mazurkiewicz, B. Mierzwa, J. Zemek, P. Jiricek, I. Bieloshapka, Graphene oxide and reduced graphene oxide studied by the XRD, TEM and electron spectroscopy methods, Journal of Electron Spectroscopy and Related Phenomena, Vol. 195 (2014) pp. 145–154.

Resistivity of thin layer of GO

L. Stobiński, NANOMATERIALS LS

Absorbance measurements

J. Szczytko et.al., IFD UW

Band gap for GO is around 2.5 eV.

Thin semiconducting GO layers are suitable for constructing a variety of nanosensors.

Model of GO platelet

L. Stobiński, NANOMATERIALS LS

The average values are calculated from the XRD patterns.

GO reveals stacked nanostructure of 21.7 nm (diameter) × 5.4 nm (height) with a distance of 0.89 nm between 6-7 graphene layers.

Model of rGO platelet

L. Stobiński, NANOMATERIALS LS

The average values are calculated from the XRD patterns.

rGO reveals stacked nanostructure of 7.7 nm (diameter) × 1.2 nm (height) with a distance of 0.37 nm between 2-4 graphene layers.
For graphite, relevant distance is 0.335 nm.

However, SEM and TEM images show GO and RGO platelets sizes reaching up to 50 µm. That can be explained that XRD “recognizes” each crease on the surface of the GO or RGO flakes and reduces artificially the size of every platelet.