Mechanochemical conversion of graphite and activation into porous graphene-containing sorbents for removal of volatile organic compounds

A solvent-free conversion of graphite into highly porous materials suitable for removal of a broad range of volatile organic compounds (VOCs) is presented. Here we introduce a simple, versatile mechanochemical method, coupled with one-step activation, to prepare porous graphene-containing materials with high yields and porosity. These sorbents exhibited strong efficiency in capturing VOCs, including benzene, hexane, isopropanol, and acetone. The highest adsorption capacity toward the VOCs studied showed a graphene-containing sample activated with potassium carbonate, having specific surface area of 1278 m 2 /g and total pore volume of 2.34 cm 3 /g. Thanks to the preserved morphology with graphene domains and large mesopore volume, the sample adsorbed high amounts of various VOCs, including 15.20 mmol/g of benzene, 8.52 mmol/g of toluene, 10.84 mmol/g of styrene, 7.89 mmol/g of hexane, 11.95 mmol/g of isopropanol, and 11.92 mmol/g of acetone at 20 °C and a relative pressure of 0.95 (0.90 for isopropanol). This study examines adsorption of a set of VOCs under identical measurement conditions using a fully automated apparatus, which allows comparison of the adsorption performance of several porous carbons across a broad range of compounds and thus enables the establishment of meaningful structure–property relationships.