PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
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2019
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IF 3.176
Zunlan Hu,Wenlong Huo,Tianbin Zhu,Jian Liu,Zhipeng Xie
In this paper, a new nanomaterial , α-Si 3 N 4 nanobelts assembled by high density nanorods were prepared via the crystallization of amorphous Si 3 N 4 at 1450 °C for 12 h. The as-synthesized nanobelts exhibited a width of ∼900 nm and a thickness of ∼150 nm, and a depressed linear region in the central. α-Si 3 N 4 nanorods on the nanobelts had a width of 8–16 nm and a length of 400–450 nm. The nanorods were single-crystal, growing along (101) plane. The nanobelt appeared to be initiated by α-Si 3 N 4 nanorods constantly growing on the both sides of a nanowire which was caused by secondary nucleation and the growth of Si 3 N 4 microcrystals . Growth mechanism related to the formation of the nanobelts was analyzed in detail on the basis of vapor-solid mechanism and secondary nucleation. The current work would provide new insights into α-Si 3 N 4 nanobelts assembled by nanorods which play an important role in nanoscale devices and show widespread potential applications due to their special morphology.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
NANOTECHNOLOGY
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2020
·Vol. 31
·期 19
·194001
·
IF 3.551
Bo Wang,Xin Huang,Xiao-Nan Zhou,Qiang Zhi,Liu-Cheng Hao,Zi-Xuan Li,Shan Zhao,Bao-Qiang Hou,Jian-Feng Yang,Kozo Ishizaki
One-dimensional Si3N4 nanostructures are desirable for constructing nanoscale electric and optoelectronic devices due to their peculiar morphologies. Herein, a facile and environmentally friendly catalyst-free method is proposed to synthesize ultra-long single crystal α-Si3N4 nanobelts via carbothermal nitridation of carbon nanotubes at 1750 °C. The obtained α-Si3N4 nanobelts with a flat surface (thickness of ∼150 nm, length of several millimeters) exhibited an extremely high aspect ratio, perfect crystal structure, and high specific surface area of 7.34–10.09 m2 g−1. In addition, the width was increased from approximately 80 nm to 8 μm by increasing the holding time from 1 to 3 h. The nanobelt formation was governed by the vapor–solid (VS) reaction between SiO vapor, N2 and carbon nanotubes, and the vapor–vapor reaction between SiO, CO and N2. The former was responsible for the initial nucleation and successive base-growth of α-Si3N4 nanotubes. The latter additionally contributed to the nanorod and subsequent proto-nanobelt formation and to the growth of the nanobelts. During high-temperature annealing at 1750 °C, the original Si3N4 nanotubes gradually transformed into nanorods, and, finally, nanobelts with stable shapes as a result of surface energy minimization.
研究领域:
材料科学
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纳米技术
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产品关联
DOI
PubMed
高影响因子
International Journal of Applied Ceramic Technology
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2021
·Vol. 18
·期 4
·1183-1191
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IF 1.968
Sen Wang,Feng Liang,Saisai Li,Liang Tian,Shaowei Zhang,Quanli Jia,Shuai Chang,Sheng Yan,Haijun Zhang
Monophase α-Si 3 N 4 was prepared by a salt melt strategy using Si as a starting material. The results showed that molten salt enhanced the conversion of Si to monophase α-Si 3 N 4 , and some as-synthesized α-Si 3 N 4 nanoparticles had a hexagonal platelet morphology. The α-Si 3 N 4 hexagonal nanoplatelets had an average lateral dimension of about 170 nm and a thickness of about 5.2 nm. The nitridation of Si in molten salt was investigated by a thermal quenching method, and the silicon halide intermediate products were detected by X-ray photoelectron spectroscopy. Silicon halides possessing higher reactive activity facilitated the nitridation of Si and nucleation of α-Si 3 N 4 . Furthermore, the lattice mismatch between α-Si 3 N 4 and the salts was calculated, suggesting that the lateral growth of α-Si 3 N 4 nanoplatelets had been guided by the salt crystal structure. Based on the results, the relevant formation mechanism of α-Si 3 N 4 nanoplatelets was proposed.
研究领域:
材料科学
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纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Zunlan Hu,Jian Liu,Zhipeng Xie
Silicon nitride (Si 3 N 4 ) particles with different morphologies have been used in many fields. In this work, α-Si 3 N 4 whiskers and granular particles with high-phase purity were successfully tailored by the controllable crystallisation process of amorphous Si 3 N 4 powders under different N 2 pressure. Impressively, α-Si 3 N 4 whiskers were prepared by simply heat treating amorphous Si 3 N 4 powders at 1550 °C for 2 h under the low N 2 pressure of 0.2 MPa, whereas equiaxed α-Si 3 N 4 particles with uniform size of ~280 nm were obtained under an elevated N 2 pressure of 2.0 MPa. With the evaluated N 2 pressures and temperatures, large scale α-Si 3 N 4 whiskers or equiaxed α-Si 3 N 4 particles could be produced. The growth mechanisms of the α-Si 3 N 4 particles with distinct morphologies were rationally proposed, and these consist of two main growth processes. First, amorphous Si 3 N 4 powders decomposed into Si(g) and N 2 (g) under high-temperature treatment. Subsequently, N 2 (g) dominated the recombination of the evaporated chemical with the Si 3 N 4 molecule. The initial N 2 concentration, which plays a key role in tailoring the shape and size of products, was controlled by the N 2 pressure.
研究领域:
材料科学
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无机化学
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
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2019
·Vol. 16
·期 6
·2173-2180
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IF 1.074
Ming-Ye Yang,Bin-Bin Dong,Fei-Hong Wang,Xin Xu,Simeon Agathopoulos
This paper reports on the successful fabrication of α -Si 3 N 4 -nanowire/Y 2 Si 2 O 7 composite membranes with superhydrophobic properties, aiming to achieve a high performance in membrane distillation. The starting powder mixture of 87 wt% γ -Y 2 Si 2 O 7 , 5 wt% Si, 3 wt% LiYO 2 , and 5 wt% ferrocene catalyst was dispersed in a stable suspension, and after being tape-casted, it was sintered at 1300°C for 4 hours in order to obtain the composite membrane. α -Si 3 N 4 nanowires with a diameter of about 50 nm were formed, distributed uniformly on the surface and in the pores of the membrane and their presence greatly favored superhydrophobicity. After surface modification with a robust hydrophobic layer of SiNCO nanoparticles, strongly adhered to the surface of the produced membrane, a water contact angle of 153 o , was measured. Water desalination experiments, using a sweeping gas membrane distillation (SGMD) device, were conducted. High water flux of 11.91 L/m 2 /h was achieved for a 4 wt% NaCl feeding solution at 90°C. Stable water flux and rejection rates were recorded in long-term experiments (>500 hours) using the produced superhydrophobic composite membrane.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Zunlan Hu,Yiyao Ge,Jian Liu,Zhipeng Xie
In this paper, α-Si 3 N 4 nanobelts assembled by Si 3 N 4 microcrystals on the nanowires were synthesized from amorphous Si 3 N 4 powders that were prepared by thermolysis of silicon diimide powders. By prolonging the heating time at 1550 °C, the amorphous Si 3 N 4 powders were converted to hexagonal phase α-Si 3 N 4 microcrystals which were adhered to the surface of nanowires to obtain α-Si 3 N 4 nanobelts. The obtained α-Si 3 N 4 nanobelts were hollow in the centre with a width of ∼850 nm and a thickness of ∼150 nm. Microcrystals were deposited on the surface of 2–3 parallel nanowires. The diameter of the Si 3 N 4 microcrystals was 30–230 nm, and the diameter of the nanowires was 50–100 nm. Evaporation of the amorphous Si 3 N 4 powders released Si vapour and N vapour, which led to the formation of the Si 3 N 4 microcrystals. The nanowires grew on the surface of the amorphous Si 3 N 4 powders due to the nucleation and diffusion of Si and N atoms of amorphous Si 3 N 4 powders. The growth mechanism of the products with unique morphology can be considered as a combination of vapour-solid mechanism and secondary nucleation process.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
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2024
·
IF 4.2
Zunlan Hu,Fangnan Zhao,Zhipeng Xie
A facile procedure was provided to obtain amorphous Si 3 N 4 powder via a liquid-phase method, followed by a heat treatment process to realize tailorable shapes for α-Si 3 N 4 crystal, while Si 3 N 4 granules were synthesized and whiskers were inhibited. The influence of the temperature on the particle morphology and growth mechanisms were investigated. Characterizations indicated that the crystallization temperature played an important role in controlling the morphology of α-Si 3 N 4 powder, while the relatively lowly temperature (below 1519 °C) was beneficial to forming whiskers. The growth of Si 3 N 4 whiskers, derive from the reaction between SiO(g) and N 2 , follows the vapor–solid (VS) mechanism, which is inhibited by the increase in temperature. Instead, higher temperatures were conducive to forming granular structures. Highly crystalline α-Si 3 N 4 granules were prepared at 1550 °C due to Si*(g) and N*(g) recombining to Si 3 N 4 nuclei via the vapor–solid-solid (VSS) mechanism providing a theoretical basis for inhibiting the production of the whiskers.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2017
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IF 6.035
Lin Li,Jun-Wei Wang,Hao Zhong,Lu-Yuan Hao,Hamidreza Abadikhah,Xin Xu,Chu-Sheng Chen,Simeon Agathopoulos
The α-Si 3 N 4 membrane was prepared by tape casting of silicon slurry, followed by calcination at 1300 °C in flowing NH 3 gas. It comprised of α-Si 3 N 4 nanowire of diameter 70 nm which were converted from silicon powder via the vapor–liquid–solid (VLS) growth mechanism. The surface of the obtained membrane was transformed from hydrophilic to superhydrophobic , with a high water contact angle of ~ 160°, by coating with a vesicular SiNCO nano-layer. The experimental results showed that nanowire structure also favored superhydrophobicity. Water desalination performance of the membrane was tested with a sweeping gas membrane distillation (SGMD) device. High water flux of 8.09 l m −2 h −1 was achieved for 20 wt% NaCl aqueous solution in the feed at 90 °C, which was maintained for more than 500 h.
研究领域:
材料科学
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化学工程
·
水处理
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Chengzhi Xu,Lei Yang,Jieliang Su,Jianping Zhang,Jiakai Cao,Xiaodong Li,Gang He,Zhanggui Hu
Silicon nitride (Si 3 N 4 ) with α -phase content ∼90.0 wt% and oxygen content ∼1.00 wt% was prepared by combustion synthesis method using recycled silicon waste from photovoltaic industry. The effects of reaction pressure and environmentally-friendly new additive C 3 H 6 N 6 on the phase composition, and morphology and reaction mechanism of the combustion synthesized α -Si 3 N 4 powder were studied. The results indicate that a lower N 2 pressure is conducive to increasing the α -phase content and reducing the oxygen content of the Si 3 N 4 powder. The addition of C 3 H 6 N 6 as an effective additive facilitates the deoxidation and nitridation reactions of recycled silicon waste, which further increases the α -phase content and reduces the oxygen content of the Si 3 N 4 powder. This work demonstrated that the recycled silicon waste from photovoltaic industry holds great promise to be used as the silicon source for the cost-effective synthesis of high quality α -Si 3 N 4 powder.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Silicon
·
2021
·Vol. 14
·期 11
·6341-6350
·
IF 2.67
Xu Hongli,Jin Xing,Zhou Xuetong,Du Xinghong,Xing Pengfei,Zhuang Yanxin
In this paper, the acceleration effect of nickel (Ni) on the direct nitridation process of the diamond-wire saw powder (DWSP) was investigated. The DWSP doped with Ni additives were nitrided at different temperatures. To study the mechanism of accelerated nitridation, the thermodynamics of Si-O-N-Ni and nitridation processes were analyzed by FactSage 7.2 and single-crystal silicon blocks were also nitrided instead of the DWSP. The results revealed that Ni decreased the nitridation temperature at which the DWSP began to gain significant weight and exhibited an excellent accelerating effect on the nitridation of the DWSP. At 1300°C the DWSP containing 2.0 wt% Ni additives had been completely nitrided within 2 h, whereas the DWSP without Ni additives had not been nitrided yet. Based on the equivalent substitution experiment, it could be concluded that the presence of Ni additives accelerated the nitridation and promoted the formation of the α-Si 3 N 4 nanorods through facilitating the generation of the SiO(g) and destructing the silica film on the surface of silicon at lower temperature. Meanwhile, Ni additives also played an important part in the growth of α-Si 3 N 4 nanorods by forming liquid Ni-Si alloy in the product.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of the Korean Ceramic Society
·
2026
·
IF 4.4
Yan Long-Pan,Zhang Guo-Hua
α-Si 3 N 4 and SiC powders were prepared from reaction between SiO 2 and carbon black in different atmosphere. The effects of atmospheres, raw material particle sizes, and C/SiO 2 molar ratio on the syntheses of Si 3 N 4 and SiC powders were investigated. The optimal parameters for preparing α-Si 3 N 4 were determined to be a temperature of 1500 °C for 8 h with a C/SiO 2 molar ratio of 4.0. In addition, the results demonstrated that H 2 atmosphere facilitated SiC synthesis by lowering its formation temperature. SiC powders were synthesized under a flowing H 2 atmosphere at 1500 °C for 5 h. N 2 -H 2 mixed atmosphere inhibited Si 3 N 4 formation while promoting SiC synthesis, with increasing SiC content as the H 2 partial pressure rose. Meanwhile, the size reduction of raw materials was conducive to promoting the formation of Si 3 N 4 and SiC and reducing the granularity of the final product. However, if the particle size of the raw materials was too fine, the product will tend to agglomerate.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·Vol. 44
·期 17
·22003-22007
·
IF 3.057
Zunlan Hu,Tianbin Zhu,Weiwei Wu,Zijun Peng,Feng Hu,Zhipeng Xie
Novel polycrystal α-Si 3 N 4 submicron rods have been successfully prepared from amorphous Si 3 N 4 powders. As-synthesized submicron rods have oblate section, with the size of 110–150 nm in height, 150–300 nm in width and 3 µm to tens of micrometers in length. Underlying growth mechanism was rationally proposed based on the results of X-ray diffraction analyses, scanning electron microscopy and transmission electron microscopy observations. It was demonstrated that the nucleation and crystal growth of α-Si 3 N 4 occurred simultaneously during the fabrication process of submicron α-Si 3 N 4 rods. The growth of α-Si 3 N 4 submicron rods follows vapor-solid-solid mechanism. The submicron rods grew from the surface of amorphous Si 3 N 4 powders in N 2 atmosphere without catalysts. The silicon monoxide vapor [(SiO)g], as a reaction intermediate, reacted with nitrogen [N 2 ] to form α-Si 3 N 4 seeds, further growing into the Si 3 N 4 nanowires. Finally, the Si and N atoms deposited on the surface of Si 3 N 4 nanowires and rearranged to form submicron rods.
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）