Cellulose nanofibers-based green nanocomposites for water environmental sustainability: a review

Lightweight, flexible, and free-standing composite material for water purification has attracted a lot of interest recently. Renewable biomaterials such as green nanocomposites based on cellulose nanofibers (CNF) will play a major role in establishing the sustainability of water. Here, we have explained chemically modified CNFs with carboxylic surface functional groups by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) oxidation and chemically bonded nanocomposites based on modified CNFs with various metal pillars or metal–organic frameworks to create a robust and high-efficiency material for various environmental applications for water purification. The functionalization of CNFs proves to be an effective approach to control the porosity via the inter-fiber electrostatic interactions and to provide active functional groups for the chemical interaction with active components for the composite film formation. The flexible film thus produced was used for water purification and microbiological activity.