The synthesis of nanostructured SiC from waste plastics and silicon powder

Abstract

Waste plastics constitute a growing environmental problem. Therefore, the treatment ofwaste plastics should be considered. Here we synthesize 3C-SiC nanomaterials coexistingwith amorphous graphite particles utilizing waste plastics and Si powder at 350–500 °C in a stainless steel autoclave. 3C-SiC could be finally obtained after refluxing with aqueousHClO4 (70 wt%)at 180 °C. X-ray powder diffraction patterns indicate that the product is 3C-SiC with the calculated latticeconstant a = 4.36 Å. Transmission electron microscopy (TEM) images show that the SiC samples presentedtwo morphologies: hexagonal platelets prepared by the waste detergent bottles or beveragebottles and nanowires prepared by waste plastic bags respectively. The correspondingselected area electron diffraction (SAED) pattern indicates that either the entire hexagonalplatelet or the nanowire is single crystalline. High-resolution TEM shows the planarsurfaces of the SiC platelet correspond to {111} planes; the lateral surfaces are {110} planesand the preferential growth direction of the nanowires is along [111]. The output of SiC was∼39% based on the amount of Si powder.