Eco-friendly approach for the construction of biochar-based superhydrophobic membrane for effective oil/water separation

Abstract

Abstract Researchers are looking at improved oil/water separation techniques due to the industry’s struggles with the separation of oily wastewater. One promising approach is to use superhydrophobic, SHP, membranes to separate oil from oily wastewater. In this study, we developed SHP textile fabric based on biochar, BC. The BC was synthesized from banana leaves by pyrolysis and then modified with nickel metal to produce Ni@BC. The textile fabric, TF, was submerged in an ethanolic solution of Ni@BC, and stearic acid, SA, to produce the SHP coating. The Ni@BC was utilized to improve the roughness of the surface of the pristine TF, and SA was utilized to reduce its surface energy. Scanning electron microscope, SEM, was used to investigate the surface morphology of the pristine and modified TF. The SEM results show that the modified TF shows a micro-nano structure. Atomic force microscopy, AFM, was utilized to study the surface roughness. The results show that the modified TF has a surface roughness greater than the pristine TF. The energy-dispersive x-ray spectroscopy techniques and Fourier transform infrared spectroscopy confirmed the structure of Ni@BC and the grafting of both SA and Ni@BC to the TF. The wettability finding demonstrated that the modified TF had a high degree of superhydrophobicity, with a high-water contact angle of 161° and a low water sliding angle of 1°. The modified TF showed excellent oil/water separation performance, with a separation efficiency of 99.9%. The oil absorption capacity of the TF was also high, with a capacity of 303 g g−1 for silicone oil, and it also has a high flux rate. The modified TF was also found to be mechanically and chemically stable, with no significant degradation after 10 cycles of use. The results of this study demonstrate that the biochar-based SHP TF is a promising material for oil/water separation.