Superhydrophobic Fe-Ni coating fabricated through simultaneous electrochemical dissolution-deposition process of nickel pig iron

The anode materials used in electrodeposition for the fabrication of superhydrophobic coating was mainly corrosion-resistant precious metals. To reduce the preparation cost and simplify the experimental operation, some cheap alloys can be used to prepare superhydrophobic coatings by direct electrolytic deposition. In this work, a facile and inexpensive method for the preparation of superhydrophobic coating has been proposed using nickel pig iron as the anode and its dissolution products as deposition raw material. The optimal preparation conditions for the coating were 0.5 mol L⁻¹ HNO₃, 0.2 mol L⁻¹ H₂SO₄, 20 mg L⁻¹ XG, and 0.16 A cm⁻² at 25°C for 20 min, and the contact angle and sliding angle of the coating was 155.6° and 3.5° after the modification with stearic acid which all reach the state of the superhydrophobic. The coating consisted of two different layers under the effect of anomalous co-deposition between the nickel and iron, which can be controlled to change the compositions of the coating to prepare a single layer for the different applications. In addition, the coating demonstrates excellent self-cleaning ability, strong adhesion to the substrate, and high corrosion resistance (charge transfer resistance=1.37×10⁴ Ω cm⁻²), which helps to realize its practical applications. This innovative method not only provides a new application for other cheap alloys, but also contributes to the industrial production of superhydrophobic coatings.