Cement based nanofiltration membrane of porous boron nitride and graphene oxide for effective oil/water separation

The development of effective filters for crude oil/water separation presents a critical environmental challenge in the face of oil spills. Porous membrane separation stands as a vital technique for removing organic solvents, oils, and dyes from water. In this study, we designed and fabricated a nanofiltration membrane composed of graphene oxide (GO) and boron nitride (BN) incorporated into a cement-based matrix to enhance the selectivity and efficiency of unidirectional flux transportation. The integration of GO, with its rich functional groups, and BN, known for its hydrophobic properties, within the cement matrix, resulted in an improved water permeation rate. Moreover, the inclusion of BN flakes in the cement matrix significantly enhances its mechanical strength, reaching up to 15.93 MPa (∼35 % greater than pristine cement), establishing it as a robust nanofiltration membrane for simultaneous flux enhancement and water purification. This innovative filter demonstrated remarkable separation efficiency, achieving up to 99 % oil removal while allowing the passage of water. To gain a deeper understanding of our experimental findings, we conducted ab initio investigations into the adsorption behavior of water and oil components, including ethanethiol, thiophene, and toluene molecules, on h-BN, GO, and their defective structures (Stone-Wales defect). Our results affirm that porous h-BN and GO nanosheets, characterized by their high specific surface areas, exhibit remarkable sorption capabilities. This nanoengineered membrane showcases substantial adsorption capacity alongside physisorption characteristics suitable for recycling, thereby holding significant potential for the development of functional porous structural materials in the realm of high-performance, cost-effective, and environmentally sustainable water treatment solutions.