Electrochemical fabrication of superhydrophobic and superoleophilic coating: applications in corrosion-resistant surfaces and oil cleanup

In this study, one-step electrodeposition method was used to achieve a superhydrophobic and superoleophilic coating. Since the obtained coating was magnetic, superhydrophobic and superoleophilic, it was evaluated from the viewpoint of anti-corrosion and oil cleanup applications. The Fourier transform infrared spectra (FTIR) and X-ray diffraction (XRD) results indicated that the superhydrophobic surface was composed of γ-Fe2O3 and Fe(CH3(CH2)12COO) compositions. The water and oil contact angles on the coating were as large as 160 and approximately 0°, respectively. Using the potentiodynamic polarization test, it was found that the corrosion rate of the superhydrophobic surface was reduced by more than five orders of magnitude than the bare carbon steel in NaCl solution. The electrochemical impedance spectroscopy results demonstrated that the total impedance of the superhydrophobic surface significantly increased when compared to the bare carbon steel. Moreover, a powder was obtained by detaching the coating from the surface. The resulting powder was superhydrophobic and superoleophilic and also had magnetic properties. The results showed that the polyurethane sponge modified by the obtained powder could separate oil from water.