Synthesis and characterisation of SiC nanomaterials from reaction of palm kernel shell and silica

Abstract

Silicon carbide (SiC) is one of the non-oxide ceramic materials that are widely developed due to its superior properties. Typically, SiC nanomaterials are synthesised by using high purity of silicon react with high purity of carbon. In this study, palm kernel shell (PKS) with high content of the carbon as the carbon source and silica (SiO2) as the raw materials to synthesise of SiC to reduce the disposal issue of PKS. The ratio of the PKS and silica powder studied are 1:1, 3:1, 5:1 and 7:1. The mixtures were heated by using microwave at 1400ºC for 40 minutes. Microwave heating can shorter the synthesis time, save energy source and operates at low temperature. SiC nanowhiskers were successful synthesised and the average diameter of the whiskers 53nm. The growth of the SiC nanowhiskers is through the VLS mechanism. The FTIR and XRD analysis show the presence of the SiC. When increased the ratio of PKS:SiO2, the SiC nanowhiskers produced were increased as well. The intensity of SiC peak in the XRD pattern has increasing when increased of the ratio of PKS to silica. TGA curve have show the oxidation of carbon residual in the sample and oxidation of SiC at high temperature. The SiC nanowhiskers produced have show a blue-shifted peak in the PL spectra and with a band gap of 2.57eV. The optimum ratio of PKS to silica is 5:1.