Adsorption of toluene with water on zeolitic imidazolate framework-8/graphene oxide hybrid nanocomposites in a humid atmosphere

Abstract

Water vapor often present in the atmosphere will influence the adsorption of volatile organic compounds (VOCs). The competitive adsorption behavior of toluene and water vapor on synthesized zeolitic imidazolate framework-8 (ZIF-8) and graphene oxide (GO) hybrid composites was investigated in a humid atmosphere. The ZIF-8/GO composites were successfully prepared in a methanol system at room temperature and exhibited tunable nanoscale morphology and surface area, both determined by the GO content. A series of characterization techniques confirmed the formation of strong interactions between ZIF-8 and GO in the synthesized composites. Adsorption experiments demonstrated that the ZIF-8/GO composites with a GO content of 4 wt% had the highest toluene adsorption capacity of 116 mg g⁻¹ at a relative humidity (RH) of 55%, increased by 19% compared with pristine ZIF-8, and the recyclability of the adsorbent was investigated. The results showed that the synthesized ZIF-8/GO composites exhibited a higher toluene uptake capacity than pristine ZIF-8 crystals even at relatively high humidity, indicating that the ZIF-8/GO composites could be effective adsorbents in a humid atmosphere.