Controlling synthesis of defect state lignin-derived carbon and application for U(VI) removal from aqueous solution: Effects of oxygen-defect and grain-size

Lignin has deemed to be the main polluting component of paper industry wastewater. But developing a potential strategy for utilization of lignin is a challenges problem. Lignin derived materials present potential performance for heavy metal wastewater treatment due to their unique physicochemical properties, and were found to be promising candidate materials in U(VI) removal. However, it is still lacking of a comprehensive understanding that the influences of surface oxygen-defect and grain-size on U(VI) removal processes. Here, using lignin as the raw material, combining plasma treatment technology to prepare defect states Lignin Derived Carbon (LDC), and exploring the influences of surface oxygen-defect and grain-size on their removal U(VI) process. The results indicated that with the reducing of LDC particle size (from ∼4 to ∼ 1 μm), the removal performance of U(VI) was improved. And the U(VI) removal performance of LDC was further improved by introducing of oxygen defect via H₂ plasma etch. The characterization analysis of defect states LDC before and after reaction with U(VI) shown that the U(VI) removal mechanism was dominated by defects site complexation. These finding provide deep insight into the recycling of industrial solid wastes lignin and improving of U(VI) removal performance via defect controlling technology.