Can graphene-based composites and membranes solve current water purification challenges - a comprehensive review

Harnessing graphene sheets' large surface area, catalytic effect, adsorption capacity, and reactivity, its use in composites for water treatment is on the rise. With ever-increasing newer pollutants in wastewater streams, treatment challenges are huge. Additionally, water scarcity puts an enormous demand on researchers to develop an integrated efficient system for desalination and wastewater purification. Can graphene-based composites and membranes meet water desalination and purification challenges? In this review, we provide a comprehensive report on the current graphene-based composites and membrane research. We laid out a systematic interrogation of present water purification techniques including desalination, shedding light on the prominent techniques that use graphene-based composites and their membranes. Not only are the fundamentals of the water purification mechanism, aspects of filtration device fabrication, and structural alteration parameters elaborated but how conditions affecting water filtration and use of eco-friendly graphene-based evaporators are emphasized. We also discuss underlying commercial aspects relating to the scale-up of the water treatment issues and highlight promising advances. Graphene's use provides cost-effectiveness and sustainability which are keys to its success. Our overall aim has been to connect the dots among the challenges of existing techniques, processability, scalability of graphene-based composites, and membranes for desalination and water purification methodologies.