Preparation and characterization of graphene oxide/chitosan composite aerogel with high adsorption performance for Cr(VI) by a new crosslinking route

A new 3-glycidoxypropyltrimethoxysilane (KH-560) cross-linked graphene oxide/chitosan (GO/CS) composite aerogel was synthesized by sol-gel and freeze-drying methods. In this study, the three-dimensional porous network structure of composite aerogel was established by the self-assemble interaction between CS and GO, and by the crosslinking reaction between CS and KH-560. GO could enhance the strength of aerogels and keep porous structure stable, and KH-560 was used to avoid the dissolution of CS in acid conditions. The chemical properties, microstructure and thermal properties were investigated by FTIR, XPS, SEM, and TGA. The adsorption performance of composite aerogel was also studied. The results indicated that the process followed the Langmuir monolayer adsorption and pseudo-second-order kinetic model. The adsorption could reach equilibrium within 120 min, and the maximum adsorption capacity could reach up to 146 mg g(-1); the aerogel adsorbent showed the good reusability and high adsorption capacity for Cr(VI) in coexistence with other ions.