Chemical removal of formaldehyde at ambient condition based on graphene composite aerogels with hydrazide-decorated polymers generated by RAFT mechanism

Volatile organic compounds (VOCs) are by far the most common indoor air pollutants. Gaseous formaldehyde (HCHO), as a type of VOC, is extremely hazardous to human health. In particular, HCHO has a mutagenic effect and can cause leukemia. Therefore, it is urgent to develop an efficient and practical HCHO removal method that can eliminate it in a green and efficient mode. Based on the demand orientation, we synthesized a hydrazide-decorated polymer (PHA) by RAFT polymerization and complexed it with reduced graphene oxide (rGO). The prepared composite material is treated via deprotection to obtain rGO/PHA. And then, the rGO/PHA aerogel was fabricated by the cross-linking mechanism using calcium chloride and sodium alginate, and used to remove gaseous HCHO at ambient condition. rGO/PHA realized the irreversible chemical removal of HCHO by means of a nucleophilic addition reaction between the hydrazide group and the aldehyde group. H 2 O is the only by-product of the reaction and no other secondary contamination was generated. Most importantly, the HCHO removal rate of the material can reach 342.53 mg/g, which up to 95.1 % of the theoretical removal amount. In addition, the aerogel can be regenerated in weak acid medium many times. After 15 cycles, the HCHO removal capacity can still be maintained at 84.83 %.