Enhanced toluene adsorption over carbon–silica composite with promoted microporosity and moisture resistance

Abstract

Herein, carbon–silica composite materials were prepared by introducing biomass-derived carbon into the channels of silica gel by concurrent thermal carbonization and chemical etching. With the optimized preparation parameters, a trade-off for the microporosity, carbon contents and toluene adsorption capacity was realized. Moreover, the TEM-EDS spectra evidenced that the carbon generated by chemical activation was homogeneously dispersed in the channels of the silica gel. Notably, when used in toluene adsorption, high adsorption capacity, desorption efficiency and regenerability were simultaneously achieved on the carbon–silica composite sample, along with superb water resistance (up to 80 RH%), as contrasted with the performances of the commercial zeolite adsorbents. Finally, except for the toluene, the composite material demonstrated good adsorption capacity and desorption efficiency for a series of common VOCs species (including acetone, ethyl acetate, n-hexane) as well, but the adsorption towards less polar adsorbates, such as n-hexane and toluene, was more favorable.