Electrochemically generated sol–gel films as inhibitor containers of superhydrophobic surfaces for the active corrosion protection of metals

The present work shows a new contribution to the design of superhydrophobic surfaces with the additional function of active corrosion protection, through the encapsulation of inhibiting agents. Superhydrophobic silica films are fabricated on aluminum alloy using electro-assisted deposition from sol–gel precursors. Two kinds of inhibitors, either inorganic cerium nitrate or organic benzotriazole, are incorporated into the superhydrophobic films by a two-step or a one-step route. The corrosion protection performance is investigated using electrochemical impedance spectroscopy and a scanning vibrating electrode technique, as well as by monitoring changes in the water contact angle. The results reveal that the superhydrophobic films loaded with inhibitors show greatly improved anticorrosion properties in 3.5 wt% NaCl aqueous solution.