Self-Activating Approach for Synthesis of 2,6-Naphthalene Disulfonate Acid Disodium Salt-Derived Porous Carbon and CO2 Capture Performance

Abstract

Porous carbon is considered an effective adsorbent for CO2 uptake thanks to its high textural feature, tunable surface decoration, and stable chemical/physical characteristics. Herein, a one-pot self-activating synthesis approach has been introduced to fabricate disodium 2,6-naphthalene disulfonate (NDS)-derived self-S-doped porous carbon. With this method, there is no external chemical activating agents for the activation process, and the self-activating process occurs by releasing CO, H2O, and CO2 gases during pyrolysis treatment. It was found that activating temperatures can carefully control the porous textural and elemental compositions of the as-prepared carbons. Upon the activating process, the optimal S-doped porous carbon was prepared at 700 °C, providing CO2 uptake capacities of 2.36 and 3.56 mmol/g at 25 and 0 °C and 1 bar, respectively. An in-depth investigation indicates that the joint effect of narrow microporosity and S content determines the CO2 uptake for this series of carbons. In addition, these NDS-derived self-S-doped porous carbons exhibit moderate CO2 heats of adsorption, fast adsorption kinetics, reasonable CO2/N2 selectivities, good dynamic CO2 capture capacities, and stable recyclabilities. The presented synthesis method is promising for fabricating facile carbon-based adsorbents from various organic precursors.