Processing Plastic Wastes into Value-Added Carbon Adsorbents by Sulfur-Based Solvothermal Synthesis

Abstract

Efficient strategies (degradation or recycling) for converting multifarious plastic wastes are imperative due to the resulting detriments to the environment and human life. With this in mind, the versatile and sulfur-mediated conversion of plastic wastes into value-added adsorbents is presented. The essential sulfur medium promotes the thermal polycondensation of polymer chains and leads to an impressive carbonization yield of 91%, significantly exceeding the control process without sulfur (0− 12%). The final sublimation of sulfur endowed carbon materials with high porosity (S BET up to 888 cm 2 /g), while the attack of sulfur radicals naturally results in a high sulfur content (8.66− 12.08%) of the carbon framework. Interestingly, the polar interactions (CO 2 with sulfoxides, sulfones, and sulfonic) ensured the S-doped carbon good performance in CO 2 adsorption (up to 4.6 mmol/g at 273 K), while the coordinating role of the sulfide group contributed to the heavy metal adsorption [removal efficiency of 99.5% for Pb(II) and 99.8% for Cd(II)].

Metal-sulfide/polysulfide functionalized layered double hydroxides – recent progress in the removal of heavy metal ions and oxoanionic species from aqueous solutions

“…Chemical separations allow trace-level removal of heavy metal ions besides achieving superior selectivity and faster kinetics. Among these, adsorption, ion exchange, and (reductive) precipitation mechanisms have garnered widespread attention across a diverse array of materials, including activated 21–23 and sulfur-impregnated carbon, 24–26 zeolites, 27–29 metal–organic frameworks, 30–32 layered metal-sulfides, 33 clay minerals, 34–36 various organic molecules, 37–39 and organic–inorganic composite materials. 40–43…”

Numerical Analysis of the Porous Structure of Activated Carbons Derived from Synthetic Polymers

“…Theoretically, any substance with a high content of carbon and low ash fraction can be used as a raw material for ACs production. The need for porous materials with high mechanical strength and large specific surface area for applications in power engineering and environmental protection has led to research development in recent years, particularly on ACs production from waste synthetic polymers [20][21][22][23][24][25].…”