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

Efficient strategies (degradation or recycling) for convertingmultifarious plastic wastes are imperative due to the resulting detrimentsto the environment and human life. With this in mind, the versatileand sulfur-mediated conversion of plastic wastes into value-addedadsorbents is presented. The essential sulfur medium promotes thethermal polycondensation of polymer chains and leads to an impressivecarbonization yield of 91%, significantly exceeding the control processwithout sulfur (0-12%). The final sublimation of sulfur endowedcarbon materials with high porosity (S (BET) up to 888 cm(2)/g), while the attack of sulfur radicalsnaturally results in a high sulfur content (8.66-12.08%) ofthe carbon framework. Interestingly, the polar interactions (CO2 with sulfoxides, sulfones, and sulfonic) ensured the S-dopedcarbon good performance in CO2 adsorption (up to 4.6 mmol/gat 273 K), while the coordinating role of the sulfide group contributedto the heavy metal adsorption [removal efficiency of 99.5% for Pb(II)and 99.8% for Cd(II)]. Plasticwastes are converted into value-added carbon materialsfor highly efficient CO2 capture based on sulfur-basedsolvothermal synthesis.

Automated summary

Efficient strategies for converting multifarious plastic wastes into value-added carbon materials are essential to minimize the negative impacts on the environment and human life. This study presents a versatile and sulfur-mediated conversion method, which achieves a high carbonization yield of 91% compared to the control process without sulfur. The resulting sulfur-endowed carbon materials exhibit high porosity and significant adsorption capacities for CO2 and heavy metals. This approach provides a promising solution for the efficient capture of CO2 from plastic wastes.