Polyvinyl Chloride-Derived Carbon Spheres for CO2 Adsorption.

Polyvinyl chloride (PVC) is the world's third-most widely produced plastic polymer. Directly transforming PVC to carbonaceous materials for CO2 capture provides an environmentally friendly and attractive strategy to recycle plastics. In this work, a simple and effective method was developed to prepare PVC-derived carbon spheres. In this method, the classical "spheroidization" process shaped the original PVC powders into millimeter spheres, and a special dehalogenation and cross-linking process in the presence of a phase-transfer catalyst transferred the thermoplasticity of the PVC-spheres into thermosetting, which stabilized the shape. Furthermore, by rationally adjusting the activation conditions, the porous structure of the carbon spheres was well optimized. With a specific surface area up to 1738 m2  g-1 and the developed microporous structure, the as-prepared carbon spheres showed not only excellent performance in pure CO2 adsorption (8.93 mmol g-1 , 39.3 wt% at 0 °C and 5.47 mmol g-1 , 24.1 wt% at 25 °C), but also outstanding adsorption capacity and recyclability in low-concentration CO2 capture, even superior to conventional molecular sieves.