Controlled delivery of multi-substituted triazole by metal-organic framework for efficient inhibition of mild steel corrosion in neutral chloride solution

A triazole-based compound containing multiple active groups and promising strategy of controlled delivery by metal-organic framework were developed for corrosion inhibition of mild steel in 0.5 M NaCl solution. Electrochemical analysis showed the inhibitor effectively suppressed both the anodic and cathodic reactions by forming an protective film, achieving the efficiency around 98% at an optimal concentration of 5.5 × 10−4 M. Impressively, the inhibitor loading onto MOF particles leads to a reduction of optimal dosage by a factor of 4. The equivalent concentration of the loaded inhibitor is less than 1.3 × 10−4 M. The results of electrochemical quartz crystal microbalance measurement and surface characterization indicated the controlled delivery largely enhances the inhibition ability by giving rise to densification of protective film. Combined spectroscopic analysis provided direct evidences for the inhibitor-MOF interaction and film formation mechanism.