Abstract
The processing and structural characterization of Si-based carbothermal
derivatives of rice husk (RH) was investigated. RH, an agro-waste, was used as
starting material in a single-stage processing route to produce Si-based refractory
compounds via carbothermal treatment. The processing was carried out at different
temperatures windows (900–1,900°C) at 10°C/min heating range in a controlled
atmosphere. The functional groups of the reaction products were analyzed using
Fourier transform infrared spectroscopy. The crystalline and amorphous phases
were identified by X-ray diffractometer (XRD), while the morphological features
were examined by scanning electron microscopy. It was observed that the major
functional groups present after carbothermal treatment of RH are OH− (hydroxyl),
Si–O–Si (siloxane), and Si–C groups. However, polytypes of silicon carbide (SiC) such
as 3C-SiC (C = cubic), hexagonal symmetry 6H-SiC, and mixes of 3C-SiC, 2H-SiC, and
4H-SiC were various polytypes of SiC observed for different processing temperatures
adopted. The SiC made up between 63 and 74 wt.% of the crystalline phases was
identified by XRD from the process. Hence, the carbothermal treatment explored.