Facile Fabrication of Oxidized Lignin‐Based Porous Carbon Spheres for Efficient Removal of Pb2+

Abstract With the growing environmental concerns of heavy metal pollution, great attention has been focused on low‐cost biomass to develop ecofriendly sorbents. Herein, oxidized lignin‐based carbon spheres (O‐LPCS) were fabricated by functionalizing mesoporous lignin‐based carbon spheres (LPCS). The surface area of O‐LPCS‐2 was 252.6 m 2 g −1 , with 0.852 mmol g −1 hydroxyl, 0.794 mmol g −1 carboxyl and 0.617 mmol g −1 sulfonic groups. The suitable‐size spheres also exhibited an excellent adsorption capacity for Pb 2+ from aqueous solution and could be easily separated for industrial application. The effects of pH, interfering ions, contact time and the concentration of initial solutions on the sorption process were studied. The adsorption kinetic followed pseudo‐second‐order model. Moreover, by fitting the adsorption data with the Langmuir model, the maximum adsorption amount was found to be 63.69 mg g −1 . The environmental friendliness and low cost of O‐LPCS make it to be a promising candidate to remove Pb 2+ from industrial effluents.