Preparation of porous carbon derived from a lignin-based polymer through ZnCl2 activation for effective capture of iodine.

Lignin-based porous carbon, a derivative of lignin, is acknowledged for its cost-effectiveness, stability, and environmental sustainability. It exhibits significant adsorption capacity for the removal of heavy metals and in wastewater treatment, rendering it a highly esteemed adsorbent material. However, the potential of lignin-derived porous carbon for the capture of iodine in environmental contexts has yet to be thoroughly investigated. This research aims to examine the iodine capture capabilities of lignin-derived porous carbon in both iodine vapor and iodine/cyclohexane solution. Initially, lignin derivatives (ADL) (Mn = 2.85 × 104, Mw / Mn = 1. 73) were synthesized through the graft copolymerization of lignin (Mn ≈ 2500), 4-acetoxystyrene, and dienopropyl terephthalate in ethylene glycol, utilizing azobisisobutyronitrile (AIBN) as the initiator. Subsequently, ADL was transformed into layered lignin-based porous carbon (ADLC) by one-step carbonization and zinc chloride activation. The iodine adsorption capacity of ADLC was determined to be 2340 mg/g in an iodine vapor environment and 354 mg/g in a 500 mg/L iodine/cyclohexane solution. These findings indicate that the layered porous carbon (ADLC) derived from lignin represents a promising material for iodine capture, providing an economical, stable, and environmentally friendly approach to nuclear waste management.