Electrodeposition of nanotubes for corrosion inhibition: Dual role as superhydrophobic matrix and nanocontainer for storing-releasing corrosion inhibitor

Abstract

The lotus leaf-inspired superhydrophobicity to prevent metal corrosion has garnered significant interest. The prevailing approach employs micro/nanoscale matrices to trap air and support water, resulting in short-term effectiveness due to air dissolution. Basic zinc carbonate nanotube (BZC NT), created via electrochemical anodization, dually achieves superhydrophobicity and contains 1-dodecanethiol as corrosion inhibitor for zinc. During the immersion under the water phase, the release of 1-dodecanethiol enables a corrosion inhibitor-air cushion, which is remarkably distinguished from the typical single air cushion formed in the superhydrophobic matrix. Using scanning Kelvin probe, the local micro-zone surface potential of Zn increases about 286 mV after being covered by superhydrophobic BZC NT (SHS BZC NT), exhibiting the high decrement of atmospheric corrosion tendency. Through typical electrochemical corrosion tests, the |Z|lf (lf = 0.036 Hz) of SHS BZC NT is about 9.78 × 106 Ω cm2, and the value is ca. 3 orders of magnitude larger than pure Zn (1.46 × 103 Ω⋅cm2). After soaking in a strong alkaline solution (pH = 11) for 24 h, the inhibitive efficiency of SHS BZC NT is 99.99%, demonstrating high corrosion inhibition effect.