Biochar-Bio-Cu composite superhydrophobic membrane for efficient oil-water separation

This manuscript presents the development of a superhydrophobic textile fabric (SF) for effective oil–water (O/W) separation. A biochar was synthesized by pyrolysis of banana leaves. The bio-Cu nanoparticles (bio-Cu NPs) were synthesized from grape seed extract. The biochar and bio-Cu NPs were used to enhance the surface roughness of the textile fabric. The low-cost, eco-friendly stearic acid was used as a low surface energy material. The SF achieves a water sliding angle of 1 degree and apparent contact angle of 159 degrees, indicating its superhydrophobic nature. The absorption capacity toward silicone oil (SO), toluene, and crude oil (CO) is measured at 102.2 g/g, 98.5 g/g, and 91.0 g/g, respectively, with minimal decrease after ten usage cycles. The SF exhibits outstanding O/W separation efficiencies for CO (99.6%), toluene (98.9%), and SO (97.5%) over ten cycles. Mechanical stability assessments reveal superhydrophobicity retention till a length of abrasion equal to 650 mm. Chemical stability investigations demonstrate SF’s resilience across a pH range of 1–13 over 2 h of immersion. Furthermore, the SF shows a good flux rate toward the oils used. These findings establish a promising advancement in environmental remediation and O/W separation.