Recent Developments in Two-Dimensional Materials-Based Membranes for Oil–Water Separation

Abstract

The industrialization witnessed in the last century has resulted in an unprecedented increase in water pollution. In particular, the water pollution induced by oil contaminants from oil spill accidents, as well as discharges from pharmaceutical, oil/gas, and metal processing industries, have raised concerns due to their potential to pose irreversible threats to the ecosystems. Therefore, the effective treating of these large volumes of oily wastewater is an inevitable challenge to address. Separating oil–water mixtures by membranes has been an attractive technology due to the high oil removal efficiency and low energy consumption. However, conventional oil–water separation membranes may not meet the complex requirements for the sustainable treatment of wastewater due to their relatively shorter life cycle, lower chemical and thermal stability, and permeability/selectivity trade-off. Recent advancements in two-dimensional (2D) materials have provided opportunities to address these challenges. In this article, we provide a brief review of the most recent advancements in oil–water separation membranes modified with 2D materials, with a focus on MXenes, graphenes, metal–organic frameworks, and covalent organic frameworks. The review briefly covers the backgrounds, concepts, fabrication methods, and the most recent representative studies. Finally, the review concludes by describing the challenges and future research directions.

Recent Studies of Membranes for Liquids Separation and Water Treatment

“…The contamination of water bodies by oil and other organic contaminants represents another environmental hazard with potential impacts not only on humans but also on marine and terrestrial ecosystems [ 23 , 24 , 25 ]. A review by Ezazi et al summarized the recent developments in oil–water separation membranes modified with two-dimensional (2D) materials [ 26 ]. In particular, the review focused on the membranes modified with synthetic 2D materials, including graphene family materials, MXenes, metal–organic frameworks (MOF), and covalent organic frameworks (COF).…”

“…In particular, the review focused on the membranes modified with synthetic 2D materials, including graphene family materials, MXenes, metal–organic frameworks (MOF), and covalent organic frameworks (COF). The synthesis and fabrication methods, wettability, permeation flux, separation efficiency, and the type of oils separated by these membranes were summarized [ 26 ]. The 2D materials with uniform pore size, high surface area, tunable wettability, and relatively high thermal and chemical stability were found to be effective alternatives to the current materials for developing membranes with promising separation efficiency and flux.…”

“…The 2D materials with uniform pore size, high surface area, tunable wettability, and relatively high thermal and chemical stability were found to be effective alternatives to the current materials for developing membranes with promising separation efficiency and flux. Further, these unique properties of the membranes modified with 2D materials make them highly applicable for the sustainable treatment of complex industrial wastewater [ 26 ]. Despite these advantages, this review encourages further studies on different aspects of 2D materials-based oil–water separation membranes, including thickness and durability, cytotoxicity, long-term stability, incorporating additional functionalities, and large-scale fabrication [ 26 ].…”

“…Further, these unique properties of the membranes modified with 2D materials make them highly applicable for the sustainable treatment of complex industrial wastewater [ 26 ]. Despite these advantages, this review encourages further studies on different aspects of 2D materials-based oil–water separation membranes, including thickness and durability, cytotoxicity, long-term stability, incorporating additional functionalities, and large-scale fabrication [ 26 ].…”