The Modification of the BET Surface Area by Considering the Excluded Area of Adsorbed Molecules

The BET method is known to be the conventional method for surface area measurements. Surface area determination is the result of the application of the linearized form of the BET equation to determine the volume of the adsorbed gas in the monolayer. An adsorbed molecule occupies an area that is inaccessible to other molecules on the surface. Taking this into account, we have reported a correction factor k´ as the ratio of Van der Waals constant (b) and the molar volume of the liquid (ν ̅), which corrects the monolayer volume of the adsorbed gas obtained from the BET model. As the size of the molecule increases, the obtained correction factor will be higher.