Preparation and inhibition behavior of Fe3O4/MBT nanocomposite inhibitor for mild steel in NaCl solution

Abstract The hollow Fe3O4 microspheres were firstly synthesized by solvothermal method. And then Fe3O4/MBT nanocomposite inhibitor was obtained by loading 2-mercaptobenzothiazole (MBT) inhibitor under negative vacuum impregnation treatment and characterized using transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms and vibrating sample magnetometer. The release behavior of MBT and inhibition behavior of Fe3O4/MBT nanocomposite under different magnetic field (MF) strength were evaluated by UV–vis spectroscopy, electrochemical techniques and immersion tests. The results show that the synthesized superparamagnetic Fe3O4/MBT nanocomposite shows high MBT loading capacity of 55.4 %. Under the application of MF, the release behavior of MBT from Fe3O4/MBT is dominated by Fickian diffusion and diffusion among magnetic nanoparticles, and the release rate and inhibition efficiency are less than that of without MF under the same release time. The nanocomposite has a good inhibition effect for carbon steel in NaCl solution with maximum inhibition efficiency of 95.7 %, and also possesses excellent recycling stability with loading capacity of 45.1 % and inhibition efficiency of 78.8 % after five cycles.