Preparation of the sulfur-enriched carbon material from waste plastic and application for removal of Cr(VI) from wastewater

In this work, the low-density polyethylene (LDPE) waste plastic is utilized to synthesize the sulfur-enriched porous carbon material (SPCM) through an initial sulfuric acid-assisted solvothermal treatment, followed by a two-stage activation process for Cr(VI) wastewater removal. Chemical properties of SPCM are characterized, indicating that SPCM has abundant sulfur/oxygen-containing functional groups. Cr(VI) removal amount is 250.4 mg.g
-1
at 298 K, based on Langmuir model calculation. The coexisting ions minimally impact the effectiveness of Cr(VI) removal. Cycling experiment demonstrates that SPCM has good cycling stability. The removal mechanism analysis indicates that SPCM achieves the synergistic effect of physical adsorption, electrostatic attraction and chemical reduction for Cr(Ⅵ) removal through developed pores and surface sulfur/oxygen functional groups. The SPCM exhibits considerable application potential in lithium-ion batteries.