Synergistic Coregulation of Porosity and Hydrophobicity in Carboxymethyl Cellulose-Derived Carbon Aerogels for Efficient Adsorption of Gaseous p -Xylene

Abstract

The treatment of volatile organic compounds (VOCs) has become an urgent task given the need to meet the country’s dual-carbon goals. Developing high-performance adsorbents with high capacity and hydrophobicity is the key to removing VOCs in high-humidity environments. This work proposes a comodification strategy. With KCl and surfactants used as activators and structure-directing agents, carbon aerogel (CPA-K-12SDS) was prepared from sodium carboxymethyl cellulose composited with polydopamine. Results showed that CPA-K-12SDS possessed a hierarchical porous structure, an ultrahigh specific surface area (1899 m2/g), and excellent hydrophobicity with a water contact angle of 98.8°. For gaseous p-xylene, CPA-K-12SDS showed excellent adsorption properties, and the theoretical adsorption capacity reached 600.68 mg/g. At 100% relative humidity, CPA-K-12SDS can still maintain more than 93.66% of the p-xylene adsorption capacity. It showed excellent adsorption performance for various VOCs such as toluene, acetone, and ethyl acetate. After six adsorption–desorption cycles, the adsorption capacity of p-xylene was reduced by only 7.53%, and it had excellent recyclability. This study not only provides an outstanding adsorbent for the efficient removal of gaseous p-xylene but also offers an effective approach for designing high-performance VOC adsorbents suitable for complex real-world environments.