Syntheses and Growth Mechanisms of 3<I>C</I>-SiC Nanostructures from Carbon and Silicon Powders

Abstract

Cubic silicon carbide (3C-SiC) nanostructures such as needle- and Y-shaped nanowhiskers, smooth and pagoda-shaped nanorods are synthesized on a large scale from activated carbon and silicon powders at 1250 degrees C under atmospheric pressure. The use of ball-milled silicon powders results in the formation of nanowires and nanowhiskers, whereas non-milled silicon powders lead to nanorods together with unreacted silicon powders. Residual oxygen in the growth chamber initiates the carburization reactions which can proceed without further oxygen consumption. The size and morphology of the as-synthesized 3C-SiC nanostructures are observed to be related to the size and morphology of the starting silicon particles. An oxygen-assisted gas-solid model is proposed to explain the observed nanostructures.

Synthesis of β-Silicon Carbide Nanowires by a Simple, Catalyst-Free Carbo-Thermal Evaporation Technique

“…Therefore, CO can easily react then with evaporated SiO to form β-SiC nanowires again. We believed that the β-SiC nanowires growth process follows the oxygen assisted growth (OAG) mechanism [15] because in the free catalytic growth, the process is governed by oxygen to make the availability of growth species in gas form. In Fig.…”

Direct synthesis of β-silicon carbide nanowires from graphite only without a catalyst

“…We believed that the ␤-SiC nanowires growth process follows the oxygen assisted growth (OAG) mechanism [15] because in the free catalytic growth, the process is governed by oxygen to make the availability of growth species in gas form.…”

Synthesis of Mesoporous Carbon‐Bonded TiC/SiC Composites by Direct Carbothermal Reduction of Sol–Gel Derived Monolithic Precursor

“…Titanium carbide (TiC) and silicon carbide (SiC) materials have been extensively investigated due to their excellent mechanical and functional properties, such as high hardness and wear resistance, low thermal expansion, high electrical and thermal conductivity, and great chemical inertness under non‐oxidizing conditions . Numerous techniques have been developed to synthesize TiC and SiC materials for different applications . Based on the reaction mechanism, the synthetic methods for metal carbide materials can be generally divided into four categories: (1) direct carbonization of metal elements by carbon black or an organic carbon source; (2) decomposition of carbon‐metal polymer precursors; (3) carbothermal reduction of metal oxide by chemically or physically introduced carbon; (4) reduction of non‐oxide components, for example, metal hydrides or halides .…”

“…[1][2][3][4] Numerous techniques have been developed to synthesize TiC and SiC materials for different applications. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] Based on the reaction mechanism, the synthetic methods for metal carbide materials can be generally divided into four categories: (1) direct carbonization of metal elements by carbon black or an organic carbon source; [4][5][6][7] (2) decomposition of carbon-metal polymer precursors; [8][9][10] (3) carbothermal reduction of metal oxide by chemically or physically introduced carbon; [11][12][13][14][15][16] (4) reduction of non-oxide components, for example, metal hydrides or halides. 3,17,18 Among these methods, carbothermal reduction of metal oxides remains the most common route to synthesize carbide powders because of the readily accessible raw materials and relatively inexpensive equipment used but high temperatures are usually required for completion of the carbothermal reaction.…”