Decontamination of water using guar gum (GG) derivatives and applications thereof are provided herein. For water decontamination, guar gum cinnamate (GGCi) is fabricated into nanoparticles having a high surface area that facilitates the removal of water pollutants by adsorption. Owing to its high availability, low cost, slow biodegradability and high sustainability, GG is considered promising as a next generation cost effective green material for water decontamination.