LANGMUIR
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2024
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IF 3.7
Tongguo Huo,Kai Cao,Jianxin Zheng,Dan Zhu,Yuan Lin,Yu Dai,Jian Wu
The mechanism of β-SiC preparation via chemical vapor deposition (CVD) of the SiCl4–CH4–H2–N2 system remains unclear. Consequently, the change of molar Gibbs free energy of the CVD β-SiC chemical reaction in the SiCl4–CH4–H2–N2 system has been studied by the Helsinki Software Corporation (HSC) Chemistry code for the first time. The role of nitrogen in the reaction was confirmed. Seven potential reaction pathways of CVD β-SiC were presented, and the thermodynamic equilibrium components of each reaction were calculated systematically. The most viable reaction pathway and corresponding optimal temperature range for CVD β-SiC were determined. In addition, a kinetic study of CVD β-SiC was conducted. The microscopic morphology and crystal structure of β-SiC coatings prepared on the graphite surface at different temperatures were charactered by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, etc. Ultimately, through SEM, XRD, and Raman observation, uniform and dense β-SiC coatings with fine grains and high crystallinity were successfully obtained. Furthermore, large β-SiC-coated graphite trays with diameters of 230 and 465 mm were prepared by CVD using the SiCl4–CH4–H2–N2 system, and the average thickness of β-SiC was about 100.6 μm. This study provides a theoretical basis and technical recommendations for the fabrication of SiC-coated graphite trays used in metal–organic chemical vapor deposition (MOCVD) equipment.
研究领域:
材料科学
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化学工程
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PubMed
高影响因子
Energy Storage Materials
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2023
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IF 20.4
Muya Cai,Zhuqing Zhao,Xin Qu,Jiakang Qu,Zuojun Hu,Hao Shi,Shuaibo Gao,Dihua Wang,Huayi Yin
Many heterogeneous reduction reactions are hampered by the generated intermediate products located at the interface of reactants, resulting in reducing the reaction area or slowing down the mass transfer and thereby shutting off or slowing down the reaction. Thus, removing the unwanted intermediate products from the reaction interface is key to enabling a rapid and sufficient reduction rate and rationally mediating the product sizes and structures. Herein, we employ solid NaCl to absorb the intermediate molten ZnCl 2 generated at the liquid Zn-SiCl 4 gas interface, making the reaction happen continuously and sufficiently at a relatively low temperature of below 450 °C. In addition to refreshing the reaction interface, NaCl acts as a buffer to absorb the reaction heat, ensuring the production of hollow Si inherited from the spherical liquid Zn template. As a result, the yield of Si reaches over 95% within 2 h and the Si particle size is below 200 nm. Further, the obtained Si anode has an initial Coulombic efficiency of 86.7% and delivers a capacity of 1580 mAh g −1 at 3 A g −1 after 350 cycles with a capacity retention of 90.6%. Overall, this paper provides an effective strategy for engineering the reaction interface and revalorizing waste SiCl 4 for making Li-storage Si anodes.
研究领域:
材料科学
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化学工程
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纳米技术
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能源存储
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DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
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2024
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IF 5.3
Tongguo Huo,Dan Zhu,Jianxin Zheng,Yuan Lin,Yu Dai,Jian Wu
This study systematically investigated for the first time the effects of varying the temperature, pressure, C/Si molar ratio, and H 2 /Si molar ratio on β-SiC coatings produced via chemical vapor deposition (CVD) using the SiCl 4 –CH 4 –H 2 –N 2 system. Thermodynamic theoretical calculations were performed using the HSC Chemistry software. The temperature and C/Si molar ratio considerably affected the morphology, phase, and composition of β-SiC coatings. High-quality β-SiC coatings along the (111) crystal plane exhibiting a uniform surface, high density, low roughness, and good crystallinity were successfully synthesized at 1523.15 K and 200 Pa with a C/Si molar ratio of 1.0 and H 2 /Si molar ratio of 6.5. Additionally, when N 2 was used as the dilution gas instead of Ar, the resulting β-SiC coatings demonstrated reduced roughness, fewer free carbon, increased hardness (37.05 GPa vs. 39.19 GPa), enhanced modulus of elasticity (237.26 GPa vs. 264.24 GPa), and superior coating adhesion (16.48 MPa vs. 18.29 MPa).
研究领域:
材料科学
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表面工程
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2016
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IF 2.933
Rong Tu,Dingheng Zheng,Hong Cheng,Mingwei Hu,Song Zhang,Mingxu Han,Takashi Goto,Lianmeng Zhang
Halide chemical vapor deposition process was carried out for fast fabricating oriented stoichiometric β-SiC through controlling flow rate of precursors (SiCl 4 and CH 4 ). The effects of molar ratio of C and Si precursors ( R C/Si ) on composition, preferred orientation, microstructure and deposition rate ( R dep ) were investigated. The deposits transformed from silicon-rich to stoichiometric β-SiC to carbon-rich with increasing R C/Si . 〈110〉-oriented stoichiometric β-SiC with lower density of defects were obtained at R C/Si in the range of 0.86–1.00, where the maximum R dep was 883 μm/h at R C/Si = 1.00, leading to a thickness of 1.7 mm in 2 h deposition. Formation of ridge-like morphology has been discussed based on a twin plane propagation model .
研究领域:
材料科学
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无机非金属材料
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薄膜制备技术
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晶体生长
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结构表征
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2026
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IF 4.5
Rui Li,Hongjuan Zhao,Tian Xia,Suofu Nie,Chuanhang Zhou,Qiang Zhang,Jiujiang Wang,Penghui Zeng,Maocai Shi,Honghai Liu,Xionghou Gao,Chunming Xu,Baojian Shen
A synergistic vapor-phase strategy using CHCl 3 and SiCl 4 regulates pore structure and acidity in NaY zeolite. • A one-step process constructs a hierarchical micro-mesoporous structure with Al-depleted bulk and Al-enriched surface layer. • Controllable mesopore evolution by tuning the imbalance between CHCl 3 -guided dealumination and SiCl 4 -assisted silication. • A system with Brønsted acidity (framework Si(1Al)) and Lewis acidity (extra-framework Al) is built. To overcome micropore diffusion limitations and acid site regulation in FCC zeolite catalysis, this study develops a synergistic vapor-phase modification using SiCl 4 and CHCl 3 . By tuning the agent ratio, pore structure and acid distribution are optimized while preserving NaY framework integrity. The synergy is not a simple combination but a dynamic process featuring CHCl 3 -guided dealumination and SiCl 4 -assisted silication with a moderate imbalance. CHCl 3 selectively removes Al from Al-rich sites, preserving framework Al predominantly as Si(1Al) units, which generate abundant Brønsted acid sites (BAS) and promote diffusion pathways. Meanwhile, SiCl 4 repairs framework defects and anchors extracted Al as highly dispersed extra-framework Lewis acid sites (LAS). This cooperative interaction creates a hierarchical micro-mesoporous structure with a low-Al bulk and an Al-rich surface layer, retaining abundant BAS while introducing strong LAS-achieving balanced acidity. In n-octane cracking, this architecture enhances diffusion, suppresses hydride transfer, and improves light olefin (C 3 –C 4 ) selectivity. This work provides insights into zeolite structure-performance relationships for rational catalyst design. A synergistic vapor-phase modification creates a zeolite with a hierarchical micro-mesoporous structure, featuring a low-aluminum bulk and an aluminum-rich surface. This architecture optimizes pore connectivity and acid site distribution for enhanced cracking performance. Download: Download high-res image (406KB) Download: Download full-size image
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2018
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IF 6.578
Hongmei Shen,Shuhao Wang,Hao Xu,Yong Zhou,Congjie Gao
Thin film nanocomposite (TFN) membranes with improved permeability is important in the energy-efficient reverse osmosis membrane processes. In this paper, we demonstrate a facile method for the formation of polyamide/silica TFN membranes by an in-situ interfacial polymerization of aqueous amine and acid chloride/silicon tetrachloride (SiCl 4 ) solutions. Water permeability is greatly enhanced with minimal loss in NaCl rejection. Polyamide/silica TFN membranes with 0.04% w/v SiCl 4 exhibit a pure water permeability up to 9.7 L m −2 h −1 bar −1 , which is 2.02 times more than that of the pristine thin film composite (TFC) membranes, while high rejection to NaCl (96.5%) is maintained. TEM tomograms confirm the existence of silica nanoparticles (NPs) in the thin PA film. More permeable voids are created in the cross-section of TFN membranes. Outer voids are buried underneath the PA protuberances and overhanging crumples. Inner voids and silica NPs are both encapsulated by polyamide . Top surfaces become more hydrophilic and negatively charged. With the optimal amount of SiCl 4 loading, the formation of non-selective voids around the particles is minimized. Covalent and hydrogen bonds are formed between SiCl 4 and PA polymers. These polyamide/silica nanocomposite membranes outperform many other TFN membranes in water permeability and salt rejection.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）