A robust superhydrophobic-superoleophilic stainless steel mesh with superior mechanical durability and chemical stability for oil-water separation

The dumping of industrial oily waste water and regular oil spills have become more conspicuous. Effectively separating oil/water mixtures to protect and reuse water resources is an important issue in the global scientific community. Therefore, developing durable, high-throughput materials for oil/water separation is essential. This study employs a convenient, quick, and environmentally friendly one-step electrodeposition method to prepare a zinc-cobalt stearate (STA-Zn/Co) composite-coated mesh on stainless steel. Structural analysis of the coating was conducted using SEM (Scanning Electron Microscopy), CLSM (Confocal Laser Scanning Microscopy), XPS (X-ray Photoelectron Spectroscopy), and XRD (X-ray Diffraction) technologies, and tests were performed on the wettability and robustness of the composite mesh. It turned out that the optimal STA-Zn/Co mesh exhibits optimized biomimetic structure and mechanical stability, with outstanding wettability (WCA = 161.0±0.2°, WSA = 6.0°, OCA = 0°), which holds potential for oil-water separation. The STA-Zn/Co mesh was used in oil/water separation trials for various oil-water pairs, with a separation efficiency exceeding 94 %. In addition, the STA-Zn/Co mesh exhibits remarkable self-cleaning capabilities, stability, and resistance to both acidic and alkaline environments, along with corrosion resistance. Therefore, this efficient and low-cost one-step electrodeposition method provides a promising potential approach for achieving oil-water separation.