Synthesis of SiC nanowhiskers from graphite and silica by microwave heating

Abstract

Silicon carbide (SiC) is an important ceramics for engineering and industrial applications due to its advantage to withstand in high temperatures. In this article, a demonstration of SiC nanowhiskers synthesis by using microwave heating has been shown. The mixtures of raw materials in the form of pellets were heated, using a laboratory microwave furnace, to 1400°C for 40 minutes at a heating rate of 20°C/min. The characterization process proved that the mixture of graphite and silica in the ratio of 1:3 is an ideal composition for synthesizing single phase β-SiC nanowhiskers. Vapor-solid mechanism was suggested to explain the formation of SiC nanowhiskers by the proposed microwave heating.

A Systematic Review on the Synthesis of Silicon Carbide: An Alternative Approach to Valorisation of Residual Municipal Solid Waste

“…SiC nanowhiskers were fabricated at 1400 • C for 0.5 h at a heating rate of 20 • C•min −1 by making use of graphite and silica with a ratio of 1:3 [46]. Microwave sintering by utilising graphite and silica in a ratio of 1:3 fed into a furnace synthesised SiC nanowhiskers at 1400 • C for 0.67 h [64]. Microwave heating of silica and graphite in the ratio of 1:3 in a hot plate at 1400 • C for 0.33-1 h obtained SiC nanowhiskers with minimal weight loss of 6% and band gap of 2.8 eV [65].…”

Controllable Combustion Synthesis of SiC Nanowhiskers in a Si-C-N System: The Role of the Catalyst

“…SiC NWs also show potential for fruitful applications in field emission displays, nanosensors, nanoscale electro-devices, and optoelectronic devices [1][2][3][4]. To date, many methods [5][6][7][8][9][10][11][12][13][14][15] have been applied to prepare SiC whiskers or NWs, including the most common and commercial methods such as chemical vapor deposition from silanes, thermal decomposition of rice hulls, and thermal reduction of silicon oxides, in particular on silica and carbon solid mixtures [16]. Though they are industrial production processes, there are still some shortcomings such as the large amount of energy and time consumption, the small amount of whiskers in the whiskers/particle products, and a certain amount of residual Si and C particles and low-melting Fe-Si alloy or other low-melting alloys in the products; most of all, these low-melting particles are detrimental phases in high-temperature environments.…”