Role of Intrinsic and Extrinsic Silicon on the Structure and Adsorption Properties of Lignin-Based Spherical Porous Carbon

Abstract

The influence of SiO₂ on the properties of lignin spherical porous carbon (LSC) was examined. Evidence suggested that the presence of optimal SiO₂ contributed to stabilizing the spherical structure of LSC and significantly enhanced LSC’s ability to adsorb antibiotics. Lignin/SiO₂ composite microspheres, fabricated through co-precipitation with added sodium silicate, served as precursors for C/SiO₂ composite microspheres (LSC-Si⁽⁺⁾). LSC-Si⁽⁺⁾ demonstrated excellent adsorption capacity for ciprofloxacin (CIP), sulfadiazine (SDZ), and tetracycline hydrochloride (TC). Furthermore, LSC-Si⁽⁺⁾ exhibits excellent physicochemical stability and noteworthy recyclability, maintaining high adsorption capacity after five cycles of recycling. Given the benefits of low cost, ease of production, and excellent adsorption performance, LSC-Si⁽⁺⁾-20 holds promise for removing antibiotic contaminants from wastewater.