Synergistic Multilevel Sieving Membranes: Integrating Cellular Graphene Skeleton with Continuous MOFs Nanolayer for Superior Multiphase Water Separation

Abstract

The emergence of MOF–based separation membranes has transformed liquid contaminant filtration with impressive sieving properties. However, their use in multiphase water filtration is hindered by a limited sieving range and susceptibility to collapse in solution. To address this challenge, an innovative solution is presented: the Multilevel Cellular Graphene Skeleton (MCGK) induced by femtosecond laser, onto which a continuous MOF nanolayer (CMN), specifically ZIF–8, is grown. This forms a groundbreaking multistage micron/nanocomposite pore membrane. The MCGK/CMN membrane significantly expands the range of filterable contaminants and enhances stability. It utilizes a multilevel, multi–pore size sieving strategy for effective multiphase water filtration, achieving an impressive 90% efficiency in self–driven solar steam generation sieving. Additionally, it excels in removing organic pollutants and over 80% of volatile organic compounds (VOCs), while reducing metal ion concentrations. In liquid pressure–driven filtration, it achieves complete oil adsorption and reduces VOCs and metal ion concentrations. This innovative multistage micron/nanocomposite pore membrane holds great potential for diverse practical applications and provides insights for next–generation nanofiltration membranes, promising more efficient and resilient water purification technologies in the future.