Surface functional groups adsorption isotherms, effects

N-doping has already been reported for ACF and activated carbon [150,152], It is well known that the uptake pressure and the shape of the H20 isotherm are functions of both micropore size and surface chemical properties. In this case, however, the influence of micropore size can almost be excluded and the observed difference in the uptake pressure be attributed solely to carbon surface chemistry. It is therefore reasonable to conclude that the inner pore surface of the N-doped carbon is more hydrophilic than that of the undoped one. Since the O content of the former carbon is lower than that of the latter, the above results indicate that in this case the presence of N groups is more effective for H20 adsorption. 

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