Novel technique for synthesis of silicon nitride nanowires

Abstract

Silicon nitride nanowires have been prepared by carbothermal reduction followed by nitridation of silica gel by in situ generation of ultrafine carbon as well as nitrogen over a temperature range of 1200-1350uC. Before the heat treatment dry silica gel is subjected to repeated evacuation followed by purging with ammonia. Ammonia is adsorbed on the silica gel surface and forms a ;Si-NH 2 bond which acts as a source of in situ generation of nitrogen and decomposition of dextrose provides ultrafine carbon respectively at the reaction temperature. During a high temperature heat treatment ultrafine carbon reduces the partial pressure of oxygen required for the generation and stabilisation of silicon nitride nanowires. The nanowires synthesised by this process are of 20-40 nm diameter and y1 mm length. The nanowires are characterised by XRD and filed emission SEM and EDAX.

Processing and Characterization of Silicon Nitride Nanofiber Paper

“…One-dimensional nanostructures of silicon nitride have been investigated intensively in the recent past [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. These structures include nanowires, nanorods, and nanofibers.…”

Thermal Nanowiring of E-Waste: A Sustainable Route for Synthesizing Green Si3N4 Nanowires

“…The synthesis of Si 3 N 4 nanobelts has been achieved via the following: vapor–solid thermal reactions between NH 3 and SiO; FeCl 2 -catalyzed pyrolysis of a polysilazane precursor; NiCl 2 -catalyzed pyrolysis of amorphous silicon carbonitride precursors; and catalytic-thermal chemical vapor deposition (CVD) on carbon felt substrate using silicon . Si 3 N 4 NWs also have been synthesized using various methods, such as carbothermal reduction and nitriding reactions at high temperatures, − confined reactions using carbon nanotubes as templates, nitridation of silicon powders, − oxide-assisted growth, combustion under a high N 2 pressure, hot-filament CVD or microwave plasma heating method, , thermal decomposition of a polymer using FeCl 2 powders as catalysts, solvothermal synthesis, and the nitridation of an Fe–Si catalyst …”

“…48 Si 3 N 4 NWs also have been synthesized using various methods, such as carbothermal reduction and nitriding reactions at high temperatures, 49−54 confined reactions using carbon nanotubes as templates, 25 nitridation of silicon powders, 49−51 oxideassisted growth, 55 combustion under a high N 2 pressure, 56 hotfilament CVD or microwave plasma heating method, 40,41 thermal decomposition of a polymer using FeCl 2 powders as catalysts, 16 solvothermal synthesis, 57 and the nitridation of an Fe−Si catalyst. 58 Despite above-mentioned works, no study has, to the best of our knowledge, achieved the synthesis of Si 3 N 4 nanomaterials from two waste streams. Owing to its simplicity and adaptability with feed materials derived from waste, the carbothermal nitridation technique seems to be a worthstudying technique for the sustainable production of Si 3 N 4 .…”

Direct Synthesis of α-Silicon Nitride Nanowires from Silicon Monoxide on Alumina

“…In recent years, the synthesis of Si 3 N 4 nanowires has gained significant attention. Many different methods are used to synthesize Si 3 N 4 nanowires, including carbothermic reduction [6-8], oxide-assisted growth [9], chemical vapour deposition [10], nitridation of silicon powders [11-15], combustion synthesis [16], solvothermal synthesis [17], etc. Among all these preparation methods, those with vapour phase acting as the media phase stand out as the most common route in the synthesis of high-quality nanowires, although other growth techniques, especially solution phase models, also offer unique advantages [18].…”