Three-dimensional lignin-based polyporous carbon@polypyrrole for efficient removal of reactive blue 19: A synergistic effect of the N and O groups

Reactive blue 19 is one of the abundant carcinogens commonly used in industrial applications. This study transformed industrial lignin into a lignin-based polyporous carbon@polypyrrole (LPC@PPy) by a hydrothermal-activation-in situ polymerization strategy for removal of reactive blue 19. The hydrothermal reaction and pol-ypyrrole polymerization provide abundant O and N groups, and the pore-making process promotes the even distribution of O and N groups in the 3D pore of LPC@PPy, which is favorable for the adsorption of reactive blue 19. The adsorption capacity of LPC@PPy for reactive blue 19 is 537.52 mg g(-1), which is 2.04 times the per-formance of LPC (only hydrothermal and activation process, only have O groups) and 3.36 times that of LC (direct lignin activation, lack of O and N groups). After 8 cycles, LPC@PPy still maintained a high adsorption capacity of 92.14 % for reactive blue 19. In addition, this study found that N and O groups in the material played an important role in adsorption, mainly pyridinic-N, C-OH, -COOR, -C-O- and C--C. This work provides a new strategy for the removal of reactive blue 19 and determines the groups that mainly interact with reactive blue 19, which provides a new reference for adsorption, catalysis and related fields.

Automated summary

This study transformed industrial lignin into a lignin-based polyporous carbon@polypyrrole (LPC@PPy) using a hydrothermal-activation-in situ polymerization strategy for removal of reactive blue 19. The adsorption capacity of LPC@PPy for reactive blue 19 is significantly higher compared to LPC and LC, due to the even distribution of oxygen and nitrogen groups in the 3D pore structure. LPC@PPy maintained a high adsorption capacity even after 8 cycles and N and O groups, such as pyridinic-N, C-OH, -COOR, -C-O-, and C--C, played important roles in the adsorption process.