Loading and release mechanisms of MOF-5 @ BTA-X (X = -CH3/-NH2/-CO(CH2)6CH3): Experimental and theoretical investigations

A series of MOF-5 @BTA-X (X = -CH 3 /-NH 2 /-CO(CH 2 ) 6 CH 3 ) anticorrosion composites was fabricated through loading benzotriazole derivatives in a metal–organic framework (i.e., MOF-5). Their crystal structures and morphologies were characterized by single-crystal X-ray diffraction analysis, Fourier transform infrared spectroscopy , and transmission electron microscopy . The loading–releasing mechanisms between MOF-5 and BTA derivatives were revealed by experiments and theoretical calculations. Their anticorrosion performance for copper was also evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization in 0.5 M NaCl. The corrosion product was analyzed via scanning electron microscopy and X-ray photoelectron spectroscopy. The results indicated that the loading capacities followed the order of MOF-5 @BTA-NH 2 > MOF-5 @BTA-CH 3 > MOF-5 @BTA-CO(CH 2 ) 6 CH 3 . The release rates followed the order of MOF-5 @BTA-NH 2 < MOF-5 @BTA-CH 3 < MOF-5 @BTA-CO(CH 2 ) 6 CH 3 . Furthermore, the results of theoretical calculations indicated that the differences in loading capacities depended on the polarity of the functional group. Meanwhile, the strong binding force decreased the release rate.