Effect of C:SiO2 Ratio on Heating Behavior and Photoluminescence Property of SiC by Microwave

Coal minerals and tetraethoxysilane were used to prepare SiC by microwave heating. Different C:SiO2 ratios of raw mixed powders were selected to investigate changes in the heating behavior and photoluminescence property. The prepared samples were characterized by X-ray diffraction (XRD) Raman Field-emission scanning electron microscopy (SEM) and X-ray fluorescence spectrophotometer. It was found that distinct heating behavior appeared for different C:SiO2 ratios, including the time taken to reach ~600 °C, performance of the thermal runaway, and heating rate. The changes in the complicated heating behaviors are determined by different microwave coupling, microwave plasma, and E-field intensification effects within samples with different C:SiO2 ratios. When the molar ration of carbon and silicon is 5:1, the intensity of light emission reaches maximum.