Preparation of robust superhydrophobic stainless steel mesh for Oil-Water separation through Mn-Assisted control of one-step electrodeposited Zn growth

Removing oil spills from water presents a significant challenge in environmental remediation. Among various separation materials available, superhydrophobic materials have emerged as promising solutions, notable for their efficiency, cost-effectiveness, and eco-friendliness. The precise control of micro/nanostructure synthesis plays an essential role in creating superhydrophobic surfaces. Herein, the present study demonstrates controlled growth of well-defined hexagonal platelet-like micro/nanostructures of zinc crystals. This is achieved through deliberate manipulation of the electrodeposition crystal growth process, a facet frequently disregarded in previous studies. Notably, the present work, based on the distinctive properties of the Zn hexagonal close-packed structure (hcp), focuses on the effects of incorporating Mn and deposition parameters on the performance of Zn coatings. These findings offer valuable insights into selectively constructing Zn crystal planes for future electrodeposition endeavors. The resulting zinc/manganese stearate (SZM) coating on stainless steel mesh (SSM) shows remarkable water contact angles, reaching an impressive 163.1 ± 2.4°, in accordance with the Cassie-Baxter theory. This feature facilitates highly efficient oil–water separation. Coupled with size sieving of SSM, SZM coatings exhibit an oil–water separation efficiency of up to 99.86 % and a flux as high as 55.58 kL/m2h. Furthermore, the SZM coating exhibits long-lasting superhydrophobicity and exceptional corrosion resistance, even when subjected to challenging conditions such as high temperatures up to 200℃, pressure reaching 7 kg/cm2, or exposure to chemical and mechanical stresses. These enduring properties make SZM coatings suitable for constructing gravity-based and continuous oil–water separation systems, establishing them as a practical solution for diverse oil–water separation applications.