the above answer is quite good! but BET method fails in this case because it measures the outer surface of GO grains, the nitrogen molecules are inaccessible to the interlayer spaces. Therefore, you will mearure ca 20-40 m2/g BET-surface area for graphite oxides, but this is a large underestimation of the surface area of exfoliated graphite oxide: the single graphene oxide sheets will have (depending on the degree of oxidation) a geometrical surface area of ca. 1700-1800 m2/g. It has been published as an appendix in one of our early papers on GO. Please see

T. Szabo et al, Carbon, 44 (2006) 537–545.

"Enhanced acidity and pH-dependent surface charge

characterization of successively oxidized graphite oxides"

of course this just refers to completely exfoliated GO. If you have bilayers or multilayered aggregates, this area is much smaller depending on the degree of dispersion. However, in alkaline dispersions GO should be (almost) completely exfoliated.

Brunauer-Emmett-Teller (BET) surface area measurement...

If graphene oxide is monolayer, you can easily answer this. You figure out knowing the structure, how many C atoms and how many O atoms are there say in a hexogon. Then you know mass per uni hexagon area (knowing bond length). From that onward you find answer to your question. However if you expect bilayers or multilayers are going to be formed, the area would reduce accordingly.

BET surface area measurements !! It would give you the results very quickly !!

the above answer is quite good! but BET method fails in this case because it measures the outer surface of GO grains, the nitrogen molecules are inaccessible to the interlayer spaces. Therefore, you will mearure ca 20-40 m2/g BET-surface area for graphite oxides, but this is a large underestimation of the surface area of exfoliated graphite oxide: the single graphene oxide sheets will have (depending on the degree of oxidation) a geometrical surface area of ca. 1700-1800 m2/g. It has been published as an appendix in one of our early papers on GO. Please see

T. Szabo et al, Carbon, 44 (2006) 537–545.

"Enhanced acidity and pH-dependent surface charge

characterization of successively oxidized graphite oxides"

of course this just refers to completely exfoliated GO. If you have bilayers or multilayered aggregates, this area is much smaller depending on the degree of dispersion. However, in alkaline dispersions GO should be (almost) completely exfoliated.

@Jindal...

Its not easy at all.. since oxygen in GO can exist in many states like hydroxyl, carbonyl, carboxyl, epoxy etc.. So, in order to implement your 'idea' we must first quantify all these groups which ain't easy.. The other complication is distribution of oxygen moieties, which are more likely to be at the edges than at the center of the sheet..

So,the only possible method is BET measurements. And despite the questions and complications associated with BET analysis, its the most simple and best possible method.

Oxygen moiteties must be present at the center of the sheet as well, otherwise the huge oxygen content cannot be explained. Note that the carbon to oxygen ratio is as low as 2! O can exist indeed in many states but the geometry of the carbon grid is more important than the distribution and exact surface chemistry of GO. even for relatively large differences in the oxygen content of GO, the geometrical surface area differs only in max. 10%. However BET area is magnitudes lower tahn that. It completely fails to estimate the exfoliated surface area, because nitrogen cannot access to the tremendous inner surface, which is opened up upon exfoliation.

@Shyam

No.. BET surface area can't quantify concentration of ripples..

what is the surface area for GO?

Is it still possible to get the BET surface area of GO about 80 m2/g ?

Hello Dr Ojha,

yes, It is possible, but I would expect such BET SSA for freeze-dried samples. Upon freeze-drying, the structure does not suffer as large collapse as when the exfoliated platelets are dried from aqueous suspension on air storage. Especially, high-degree oxidized Hummers-Offeman GO samples might give rise to such relative large SSA's regarding nitrogen adsorption, but I have no deeper literature data in my knowledge at this point.