Title : Metal oxide modified Silicon Carbide nanocomposites
Abstract:
Silicon Carbide has been one of the semiconductors prominently known for its attractive physical and chemical properties for several decades. It continues to be the main driving force for current and future research. Silicon carbide (SiC) exhibits high thermal conductivity, high resistance towards oxidation, high mechanical strength, low specific weight, and chemical inertness. These attributes could lead to SiC-based catalysts becoming widely used new catalytic materials for many years.
The intimate mixture of SiO2 and C in the rice husk (considered agricultural waste) provides an ideal platform for SiC synthesis. A single step has been adopted to prepare SiC directly from raw rice husk in an indigenously developed pot-type extended arc plasma reactor using graphite electrodes. The plasma-produced product was very fragile. The ultrafine SiC could easily be produced by ball milling.
This paper presents the synthesis of different metal oxides (TiO2, SO4, WO3, VPO) modified SiC nanocomposites by various wet chemical methods. The physico-chemical properties of the synthesized materials have been studied by various characterization processes (XRD, FESEM, BET, TEM, XPS, FTIR, UV-Vis DRS, PL, etc.). The catalytic activities of metal oxides promoted SiC have been evaluated towards environment pollution abatement, energy production, and industrially important organic transformation reactions. (i) A series of β-SiC/TiO2 nanocomposites (5-25 wt%) has been successfully fabricated by a sol-gel process, and the photocatalytic activities of all the β-SiC/TiO2 nanocomposites have been studied for aqueous Rhodamine B (Rh-B) dye degradation under solar light irradiation. (ii) A series of sulfate-modified TiO2/β-SiC nanocomposite photocatalysts have been fabricated by sol-gel and wetness impregnation method. The photocatalytic activity of the synthesized catalysts has been evaluated toward hydrogen energy production in the presence of visible light. (iii) A series of tungstate-promoted β-SiC catalysts (5-20 wt%) has been tested in liquid phase esteri?cation of acetic acid with n-butanol in a solvent free medium. (iv) A series of VPO/β-SiC composite materials (5-20 wt%) has been successfully fabricated by the wetness impregnation method, and the catalytic activities of VPO/β-SiC composites have been studied in a solvent-free oxidation of methanol using tert-butylhydroperoxide (TBHP) as oxidant.
