Double-Ligand Strategy to Construct an Inhibitor-Loaded Zn-MOF and Its Corrosion Protection Ability for Aluminum Alloy 2A12

A promising
double-ligand strategy for the delivery of active corrosion
inhibitors by a Zn­(II)-based metal–organic framework (Zn-MOF)
is developed. Zn-MOF compounds were synthesized by a facile one-pot
solvothermal method and characterized. The Zn-MOF is based on the
corrosion inhibitor benzotriazole (BTA) and 2,5-furandicarboxylic
acid (H2FDA) ligand, which is a promising renewable building
block alternative to terephthalic or isophthalic acid. The crystal
structure and morphology are characterized by single-crystal X-ray
diffraction analysis, powder X-ray diffraction analysis (PXRD), Fourier
transform infrared spectroscopy (FT-IR), and scanning electron microscopy
(SEM). The synthesized MOF crystallites are in the trigonal space
group R3c with the cell parameters
in a three-dimensional (3D) anionic framework. Their ability to inhibit
the corrosion process of aluminum alloy 2A12 in NaCl solution was
also evaluated by immersion tests in solutions with and without a
MOF. The postcorrosion analysis was performed by SEM and X-ray photoelectron
spectroscopy (XPS). Additional information about the inhibition efficiency
was obtained by electrochemical impedance spectroscopy (EIS). The
results suggest that the as-synthesized MOF can release the inhibitors
and form protective layers effectively on the surface of the aluminum
alloy. The use of inhibitor-loaded MOF nanocontainers provides promising
opportunities for the smart delivery of inhibitors and effective corrosion
protection of 2A12 aluminum alloys.