Growth of SiC Whiskers onto Carbonizing Coir Fibers by Using Silicon Slurry Waste

To reduce environmental pollution and waste of resources, it is very important to recycle valuable materials in silicon slurry waste (SSW). We report a novel method for the rapid preparation of SiC nanowhiskers by spark plasma (SP) assisted thermal treatment using SSW as the silicon source. In the preparation process, coir fibers were used as the carbon source and whisker growth substrate. At 1100–1300 °C, carbon-rich tadpole-like 3C–SiC whiskers with Fe catalyst caps were prepared by the vapor–liquid–solid growth mechanism. At 1400–1600 °C, carbon-rich, stick-like 3C–SiC whiskers without Fe catalyst caps with aspect ratios of about 40, and diameters of about 50 nm were prepared by the vapor–solid growth mechanism. The SiC whiskers grew along the [111] direction on the (111) plane at different temperatures. At the optimum temperature of 1500 °C, the silicon in SSW reacted completely, and SiC whiskers with good morphology were prepared. Furthermore, the photoluminescence (PL) spectra of SiC whiskers showed strong blue-violet emission at 450 nm. Accordingly, this study provides an environmentally friendly method for preparing SiC whiskers.