Biomass@MOF-Derived Carbon Aerogels with a Hierarchically Structured Surface for Treating Organic Pollutants

Abstract

Porous carbon materials are highly attractive in the research field of adsorption, particularly, for treating organic pollutants in wastewater, of which the facile yet generic method is highly pursued. In our study, carbon aerogels bearing a hierarchically structured surface were prepared through direct carbonization of Biomass@metal–organic framework (MOF) composites. Briefly, MIL-53, one typical MOF material, was in situ assembled on the surface of kapok fibers, a kind of fibrous biomass with the highest hollow degree on earth, through surface-induced mineralization. After direct carbonization, the resultant carbon aerogel, termed Biomass-C@MIL-53-C, with a hierarchically structured surface, was formed. Biomass-C@MIL-53-C exerted superwater repellence with the water contact angle of >140°, which showed adsorption capacities 35–119.5 times their own weight toward various kinds of oils and organic solvents. Additionally, Biomass-C@MIL-53-C could retain 77.2–96.7% of their initial adsorption capacity after eight adsorption-squeezing cycles, outperforming its counterpart, Biomass-C aerogel. Other organic pollutants, such as dyestuffs, in wastewater could also be effectively removed by Biomass-C@MIL-53-C, showing the potential of our biomass-derived carbon aerogels in a broad range of application areas for environmental protection.