Mxene structure: A key parameter in corrosion barrier performance of organic coatings

•Fresh and oxidized MXene are used as nanofillers in waterborne epoxy coatings.•Silane functionalization is used for loading MXene in polymer matrix.•Fresh MXene nanosheet is a better candidate for improving corrosion protection.•Oxidized MXene nanosheet has a defect structure with TiO2 nanoparticles.•Oxidized MXene could not improve corrosion resistance as much as fresh MXene.