Motivated by the existence of several recent works claiming for unusual hydrogen bonds in water adsorbed or confined in carbon nanostructures, we have analyzed the nature of a sharp O-H stretching at 3700 cm−1 in H2O/graphene recorded in vibrational measurements. The interpretation of such mode is rather controversial. On the basis of a careful inspection of our spectroscopic data and of literature, we suggest that the interpretation of this feature as a fingerprint of surface hydrophobicity, electronic effects or disorder is astray. Instead, it merely arises from interface effects.