aims to explain the physical adsorption of gas molecules on a solid surface and serves as the basis for an important analysis technique for the measurement of the specific surface area of a material. In 1938, Stephen Brunauer, Paul Hugh Emmett, and Edward Teller published the first article about the BET theory in the Journal of the American Chemical Society.[1] The BET theory refers to multi layer adsorption, and usually adopts non-corrosive gases (like nitrogen, argon, carbon dioxide, etc.) as adsorbates to determine the surface area data