Carbon layer modification on the surface of ordered mesoporous silica-based materials and its VOCs adsorption

Carbon-mesoporous molecular sieve composite materials were synthesized by introducing sucrose into the channels of mesoporous molecular sieves (SBA-15 and MCM-41) followed by chemical etching at high temperatures. By optimizing the sucrose concentration, a balance between surface area, carbon content, and toluene adsorption capacity was achieved. TEM-EDS characterization confirmed that the carbon generated through chemical activation was uniformly distributed within the channels of the mesoporous molecular sieves. Additionally, pore size distribution analysis revealed a significant increase in micropore fractions in both mesoporous materials after functionalization, leading to enhanced toluene adsorption capacity. Notably, compared to C@MCM, C@SBA maintained relatively higher toluene adsorption capacity even after five adsorption-desorption cycles, which translates to a better regenerability. Alongside their excellent adsorption performance, the carbon-mesoporous molecular sieve composites also exhibited remarkable moisture resistance, with no significant decrease in performance under increased humidity. Lastly, both composite materials demonstrated good adsorption performance for other oxygen-containing VOC species, although adsorption was more favorable for nonpolar adsorbates, such as toluene. © 2024 Chinese Society for Environmental Sciences. All rights reserved.