Few-layered mesoporous graphene for high-performance toluene adsorption and regeneration

The benzene series is one type of volatile organic compounds (VOCs) which causes significant health and environmental issues. Adsorption is an energy-efficient technique for VOC treatment. With a combination of strong π-π interaction with the benzene series, large specific surface area (SSA), tunable nanostructure hierarchy and favourable hydrophobicity, three-dimensional porous graphene materials are potentially favorable for high adsorption capacity, low-energy regeneration and good resistance to high humidity. In this work, few-layered mesoporous graphene (FLMG) with a large SSA (1990 m² g^-1) is constructed by chemical vapor deposition on porous magnesium oxide templates. The as-prepared mesoporous graphene presents a high adsorption capacity (260.0 mg g^-1) for toluene at low toluene concentration (∼120 ppm) and a high desorption ratio of 92% for regeneration even at mild heating conditions of 95 °C. Additionally, FLMG preserves 80.1% of the initial adsorption capacity even under high humidity (78%). The good adsorption performance of FLMG is due to its high SSA and high mesoporosity, which render a stronger adsorption ability, a larger adsorption accommodation and a more facile desorption behaviour. This work illustrates the further development of advanced graphene materials for enhanced VOC treatment and other environmental applications.