Carbon nanomaterials for advancing separation membranes: A strategic perspective

An emerging class of carbon nanomaterials (CNMs), in particular graphene-based materials and carbon nanotubes, has been extensively studied for its extraordinary water transport and sieving properties. However, harnessing the full potential of these CNMs as separation membranes for water treatment and desalination is a challenge. As such, we identify five strategic areas of focus, namely, concentration polarization, fouling, stability, scalability and cost to help path future research directions on CNM-based membranes. We reason that concentration polarization and fouling are limitations which compromise the performance of CNM-based membranes while mechanical stability of the membranes towards cross-flow hydrodynamics is an important prerequisite to tackle these Achilles heels. Such challenges, together with the safety profile of CNMs, membrane scalability and production costs, are potential barriers that require urgent attention and necessitate a shift in research efforts away from the pursuit of enhanced performances alone. This article therefore puts into perspective the relevance of these areas of focus and elaborates how carbon science can be leveraged as an interdisciplinary approach to develop innovative solutions essential for realizing the revolutionary promise that CNMs hold for water treatment and desalination.