Self‐Supporting Graphene Foam for the Removal of Chlorine from Water

Abstract Porous materials based on graphene attract attention due to their potential applications as sorbents or catalytic materials. However, achieving a freestanding structure without the use of additional bonding agents remains a major challenge. This article presents a self‐supporting graphene foam fabricated from an aqueous suspension of graphene oxide and hydrazine. The porous structure is obtained by the reaction of graphene oxide with hydrazine vapor. The foam is subjected to structural and chemical composition studies. Microscopic investigations, BrunauerEmmettTeller (BET), and X‐ray tomography are carried out to characterize its internal structure, including the nature and size of the pores, and to determine the specific surface area. The strength parameters of the foams are then measured, i.e., Young's modulus, tensile strength, and compressive strength. Next, tests are performed for functional applications. The ability of the foam to remove free chlorine from water is investigated. This ability far exceeds that of activated carbon (AC). The foam removes 97% of chlorine at the same time, whereas AC removes only 38%. The sorption dynamics are almost six times higher than those of AC. Cyclic sorption studies demonstrate that the foam can be used multiple times for this purpose.