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Fe(NO3)3-assisted large-scale synthesis of Si₃N₄ nanobelts from quartz and graphite by carbothermal reduction-nitridation and their photoluminescence properties.

Liu S, Fang M, Huang Z, Huang J, Ji H, Liu H, Liu YG, Wu X - Sci Rep (2015)

Bottom Line: The large-scale synthesis of Si3N4 nanobelts from quartz and graphite on a graphite-felt substrate was successfully achieved by catalyst-assisted carbothermal reduction-nitridation.The Fe(NO3)3 played a crucial role in promoting the nanobelt formation in the initial stage.The room-temperature photoluminescence spectrum of Si3N4 nanobelts consists of three emission peaks centered at 413, 437, and 462 nm, indicating potential applications in optoelectronic nanodevices.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Technology, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, China University of Geosciences, Beijing, 100083.

ABSTRACT
The large-scale synthesis of Si3N4 nanobelts from quartz and graphite on a graphite-felt substrate was successfully achieved by catalyst-assisted carbothermal reduction-nitridation. The phase composition, morphology, and microstructure of Si3N4 nanobelts were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The Si3N4 nanobelts were ~4-5 mm long and ~60 nm thick and exhibited smooth surfaces and flexible shapes. The Si3N4 nanobelts were well crystallized and grow along the [101] direction. The growth is dominated by the combined mechanisms of vapor-liquid-solid base growth and vapor-solid tip growth. The Fe(NO3)3 played a crucial role in promoting the nanobelt formation in the initial stage. The room-temperature photoluminescence spectrum of Si3N4 nanobelts consists of three emission peaks centered at 413, 437, and 462 nm, indicating potential applications in optoelectronic nanodevices.

No MeSH data available.


Unit cell model of α-Si3N4:(a1) (001), (b1) (101), (c1) (100). Projected view of lattice planes in the unit cell and lattice data: (a2) (001), (b2) (101), and (c2) (100).
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f5: Unit cell model of α-Si3N4:(a1) (001), (b1) (101), (c1) (100). Projected view of lattice planes in the unit cell and lattice data: (a2) (001), (b2) (101), and (c2) (100).

Mentions: It is believed that the morphologies of nanobelts are dominated by the combined effect of surface energy and growth kinetics23. In the previous studies on nanobelts, the number of broken bonds per unit area for each crystal plane was calculated to qualitatively compare the surface energy of the low-index planes3. In this study, the number of broken bonds for the (001), (101), and (100) planes in each unit cell were 10 (Fig. 5a1), 9 (Fig. 5b1), and 9 (Fig. 5c1), respectively. The projected view of the lattice planes in the unit cell and relative lattice data are shown in Figs. 5a2, 5b2, and 5c2. Accordingly, the number of broken bonds per unit area for each plane was calculated to be 0.19, 0.13, and 0.21 Å−2 for (001), (101), (100) planes, respectively. It can be concluded that the surface energy (δ) of three low-index planes follow the order: δ(100) > δ(001) > δ(101). The lower-energy planes can be easily the enclosure surfaces because of their smaller surface energies, whereas higher-energy planes constantly grow with the sufficient supply of raw materials. This indicates that nanobelts grow along the [100] plane, not the opposite experimental result of the [101] plane. The difference between the real growth direction and surface energy calculation shows that surface energy is not the dominating factor for Si3N4 nanobelt growth in this study. For the growth kinetics, the roles of factors such as growth temperature and flow stream parameters in determining the shape of nanobelts have not been clearly understood and need to be explored in the future.


Fe(NO3)3-assisted large-scale synthesis of Si₃N₄ nanobelts from quartz and graphite by carbothermal reduction-nitridation and their photoluminescence properties.

Liu S, Fang M, Huang Z, Huang J, Ji H, Liu H, Liu YG, Wu X - Sci Rep (2015)

Unit cell model of α-Si3N4:(a1) (001), (b1) (101), (c1) (100). Projected view of lattice planes in the unit cell and lattice data: (a2) (001), (b2) (101), and (c2) (100).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4355634&req=5

f5: Unit cell model of α-Si3N4:(a1) (001), (b1) (101), (c1) (100). Projected view of lattice planes in the unit cell and lattice data: (a2) (001), (b2) (101), and (c2) (100).
Mentions: It is believed that the morphologies of nanobelts are dominated by the combined effect of surface energy and growth kinetics23. In the previous studies on nanobelts, the number of broken bonds per unit area for each crystal plane was calculated to qualitatively compare the surface energy of the low-index planes3. In this study, the number of broken bonds for the (001), (101), and (100) planes in each unit cell were 10 (Fig. 5a1), 9 (Fig. 5b1), and 9 (Fig. 5c1), respectively. The projected view of the lattice planes in the unit cell and relative lattice data are shown in Figs. 5a2, 5b2, and 5c2. Accordingly, the number of broken bonds per unit area for each plane was calculated to be 0.19, 0.13, and 0.21 Å−2 for (001), (101), (100) planes, respectively. It can be concluded that the surface energy (δ) of three low-index planes follow the order: δ(100) > δ(001) > δ(101). The lower-energy planes can be easily the enclosure surfaces because of their smaller surface energies, whereas higher-energy planes constantly grow with the sufficient supply of raw materials. This indicates that nanobelts grow along the [100] plane, not the opposite experimental result of the [101] plane. The difference between the real growth direction and surface energy calculation shows that surface energy is not the dominating factor for Si3N4 nanobelt growth in this study. For the growth kinetics, the roles of factors such as growth temperature and flow stream parameters in determining the shape of nanobelts have not been clearly understood and need to be explored in the future.

Bottom Line: The large-scale synthesis of Si3N4 nanobelts from quartz and graphite on a graphite-felt substrate was successfully achieved by catalyst-assisted carbothermal reduction-nitridation.The Fe(NO3)3 played a crucial role in promoting the nanobelt formation in the initial stage.The room-temperature photoluminescence spectrum of Si3N4 nanobelts consists of three emission peaks centered at 413, 437, and 462 nm, indicating potential applications in optoelectronic nanodevices.

View Article: PubMed Central - PubMed

Affiliation: School of Materials Science and Technology, Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, China University of Geosciences, Beijing, 100083.

ABSTRACT
The large-scale synthesis of Si3N4 nanobelts from quartz and graphite on a graphite-felt substrate was successfully achieved by catalyst-assisted carbothermal reduction-nitridation. The phase composition, morphology, and microstructure of Si3N4 nanobelts were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The Si3N4 nanobelts were ~4-5 mm long and ~60 nm thick and exhibited smooth surfaces and flexible shapes. The Si3N4 nanobelts were well crystallized and grow along the [101] direction. The growth is dominated by the combined mechanisms of vapor-liquid-solid base growth and vapor-solid tip growth. The Fe(NO3)3 played a crucial role in promoting the nanobelt formation in the initial stage. The room-temperature photoluminescence spectrum of Si3N4 nanobelts consists of three emission peaks centered at 413, 437, and 462 nm, indicating potential applications in optoelectronic nanodevices.

No MeSH data available.