Carbon dot engineered membranes for separation - a comprehensive review and current challenges

Carbon dots (CDs) are a rapidly emerging class of nanomaterials with remarkable physicochemical properties such as small size, high surface area-to-volume ratio, tunable optical properties and facile functionalization. These properties make CDs highly versatile and attractive for a wide range of applications such as biomedical imaging, drug delivery, photocatalysis, sensing etc. Recently, CDs have shown great potential for use in membrane separation applications, where their zero-dimensional structure, hydrophilicity, tunable surface chemistry, and antimicrobial characteristics are greatly useful. These properties allow for the design of advanced membranes with improved permeability, selectivity, and durability. This review presents a comprehensive overview of the fabrication techniques of CD engineered nanocomposite membranes and effect of CDs on the membrane formation, properties, and membrane separation since the inception of this research domain. An extensive collection of data of fabrication, properties, and application of the CD modified nanocomposite membranes from the reported research studies is provided in a tabular form for easy reference. Finally, the review concludes by discussing the current challenges and providing an outlook on future directions.