DIAMOND AND RELATED MATERIALS
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2023
·
IF 4.1
Weidong Sang,Xuefeng Yang,Haitao Tian,Jialin Wang,Yuchang Wang,Zhengxin Li
During the process of sintering diamond/ceramic composites, the wettability between diamond and the ceramic matrix is poor, and there are many irregular pores in the composites, which leads a low bending strength of the composites and easy shedding of diamond. In order to solve these problems, SiO 2 -B 2 O 3 -Li 2 O-ZnO-Al 2 O 3 glass-ceramic coated diamond was prepared by a sol-gel method, and the properties of the coated diamond abrasive particles were studied. The SBLZA glass-ceramic-coated diamond exhibited high thermal stability and excellent oxidation resistance, making it a good protective material for diamond. The oxidation resistance of the SBLZA glass-ceramic-coated diamond was determined by thermogravimetric analysis (TGA). The uncoated diamond abrasive particles began to oxidize at 723 °C, while the coated abrasive particles were resistant to oxidation at temperatures up to 1000 °C. The glass-ceramic coating significantly improved the bonding between diamond and the ceramic matrix. The use of SBLZA glass-ceramic-coated diamond instead of uncoated diamond in the composites sintered at 750 °C resulted in a decrease in the volume expansion rate of the diamond/ceramic composites from 37.2 % to 28.5 %, and an increase in the bending strength from 38.4 MPa to 61.5 MPa.
研究领域:
材料科学
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涂层技术
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
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2012
·
IF 4.805
Liang You,Yiwu Mao,Jianping Ge
A surface galvanic replacement process was developed to prepare SiO2@Au-nanoring composite colloids with high activity and good recyclability for liquid-phase catalysis. The growing process can be monitored by the plasmonic absorption of composite colloids, and the formation of the ring structure can be explained by galvanic replacement confined on the colloid surface. The in situ growth strategy developed in this work provides a useful method to prepare reactive and stable nanostrucutres with the desired shape and exposed crystal facets on the supporting materials. The in situ grown SiO2@Au-NR colloid has a thin, amorphous, but permeable, silica layer extending from the colloid surface and wrapping around the Au nanoring, which firmly fixes the nanostructure without blocking the path for reactant molecules to reach the nanocrystal inside, leading to an improved stability in various chemical environments. Compared with the later-absorbed SiO2@Au-nanoparticle colloid, the SiO2@Au-NR colloids have comparable high activity and enhanced recyclability in catalysis.
研究领域:
材料科学
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化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-8
·
IF 5.578
Niu Xiaoyu,Zhao Tieying,Yuan Fulong,Zhu Yujun
The hollow CuO@SiO 2 spheres with a mean diameter of 240 nm and a thin shell layer of about 30 nm in thickness was synthesized using an inorganic SiO 2 shell coating on the surface of Cu@C composite that was prepared by a two-step hydrothermal method. The obtained hollow CuO@SiO 2 spheres were characterized by ICP-AES, nitrogen adsorption-desorption, SEM, TEM, XRD, H 2 -TPR, CO-TPR, CO-TPD and NO-TPD. The results revealed that the hollow CuO@SiO 2 spheres consist of CuO uniformly inserted into SiO 2 layer. The CuO@SiO 2 sample exhibits particular catalytic activities for CO oxidation and NO + CO reactions compared with CuO supported on SiO 2 (CuO/SiO 2 ). The higher catalytic activity is attributed to the special hollow shell structure that possesses much more highly dispersed CuO nanocluster that can be easy toward the CO and NO adsorption and the oxidation of CO on its surface.
研究领域:
材料化学
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催化化学
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纳米材料科学
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环境催化
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无机合成
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Yanyan Wang,Guobao Li,Youxin Hao,Yuhan Xie,Xintian Li,Changlong Chen,Anning Jiang
In recent years, the rapid economic development has significantly altered industrial production and human lifestyle, resulting in the exacerbation of water pollution. Consequently, photocatalytic technology has received considerable attention as an environmentally friendly and efficient approach for wastewater treatment. In this paper, WO 3 /SiO 2 /SnO 2 composite films were prepared by sol-gel method and subsequently co-doped with Ce, Fe and Ag ions. The photocatalytic performances of these modified composite films toward degradation of methyl green (MG) and tetracycline (TC) were systematically evaluated under UV and visible light irradiation. Comprehensive characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Nitrogen adsorption desorption isotherm test, UV–vis diffuse reflectance spectroscopy (UV–vis DRS), and photoluminescence (PL) spectrascopy, were employed to investigate the crystalline phase, morphology, particle size, chemical composition, specific surface area and optical properties of the prepared composite films. The PL spectral analysis revealed that the co-doping of Ce, Fe and Ag significantly enhanced the separation efficiency of photogenerated charge carrier in the WO 3 /SiO 2 /SnO 2 composite films. Radical trapping experiments demonstrated that superoxide radicals (·O 2 - ) and hydoxyl radicals (·OH) played predominant roles in the photocatalytic degradation process. Notably, the prepared photocatalyst maintained stable performance through five consecutive recycling tests, demonstrating excellent reusability. The enhanced photocatalytic activity of the WO 3 /SiO 2 /SnO 2 -Ce/Fe/Ag composite films can be attributed to the impactful suppression of electron-hole recombination through the strategic incorporation of dopant ions.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Xixi Ji,Yao Wan,Dan Xu,Xiaotong Pang,Yonggang Tong,Jingzhong Fang,Wei Xie,Yuanqiang Luo,Yaqi Ren,Yongle Hu
According to the escalating concern regarding the health hazards associated with electromagnetic radiation , the significance of absorbing materials underscores which could mitigate the healthy risks. While magnetic materials offer excellent absorption performance, their high density poses challenges to achieving optimal absorption efficiency. Conversely, carbon-based materials are known for their lightweight and versatile but face impedance matching issues. To address these obstacles, carbon/magnetic composite materials have been explored. However, their absorption performance has not fully met requirements due to weaker magnetic properties and increased density. Herein, we synthesized a porous carbon material embedded with magnetic FeNi/NiFe 2 O 4 and dielectric SiO 2 nanoparticles (FeNi-NiFe 2 O 4 -SiO 2 @PC) using carbonthermal method. By adjusting the ratio of polyvinylpyrrolidone to nitrates, the electromagnetic wave (EMW) absorption performance is adjusted. The FeNi-NiFe 2 O 4 -SiO 2 @PC composites display remarkable EMW absorption properties, achieving a minimum reflection loss of −69.9 dB at a thin thickness of 1.495 mm and a maximum effective absorption bandwidth of 5.68 GHz, covering the range from 12.32 to 18.0 GHz at a thickness of 1.92 mm. This outstanding performance can be attributed to the favorable impedance matching and the three-dimensional porous structure, which facilitates a 3D transmission network for multiple reflections. Additionally, the presence of FeNi, NiFe 2 O 4 , and SiO 2 nanoparticles enhances magnetic loss, conductive loss, interface polarization, and dipolar polarization, leading to excellent ab. Hence, this work offers insights into the composition design of high-performance absorbing materials.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jie Min,Wei Song,Tianding Hu,Yunfei Zhi,Zhenhao Xia,Tiecheng Zhang,Shaoyun Shan,Hongying Su
Magnetic nanoparticle-supported heterogeneous catalysts have been widely researched in green catalysis, due to their convenient magnetic separation and nanometer effects. Herein, a magnetic Co(III)-Salen heterogeneous catalyst with uniform spherical core-shell structure was synthesized for the chemical fixation of CO 2 into cyclic carbonate based on the sustainable protocol development and green chemistry principles. Fe 3 O 4 @SiO 2 nanoparticles with uniform spherical core-shell structure were prepared by the reverse microemulsion method, and Co(III)-Salen complexes were subsequently immobilized on the resulted Fe 3 O 4 @SiO 2 nanoparticles via covalent bonding, leading to Fe 3 O 4 @SiO 2 @Co(III)-Salen nanocomposites with particle size of 29 nm and saturation magnetization value of 27.2 emu/g. The catalytic performance study indicated that the catalyst exhibited high yield of 99% with selectivity of 100% for the ring-opening addition reaction of CO 2 and epoxide under solvent-free reaction condition. A plausible reaction mechanism was proposed that the Lewis acidic sites of Co(III)-Salen and nucleophilic bromine ion components played synergetic roles in promoting cycloaddition reactions. A stable geometry of the Co(III)-Salen complex and a detailed evidence for the reaction mechanism were provided by the density functional theory (DFT) calculations. Based on their excellent magnetic properties , the Co(III)-Salen nanocomposites could be easily recovered by using an external magnet and reused for 5 times without significant leaching of metal center and loss of catalytic activity.
研究领域:
材料科学
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绿色化学
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催化反应
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2018
·
IF 3.12
Yongpeng Ma,Bailong Mu,Xiaojing Zhang,Hongzhong Zhang,Haomiao Xu,Zan Qu,Li Gao
Hierarchical Ag-SiO 2 @Fe 3 O 4 magnetic composites were selected for elemental mercury (Hg 0 ) removal from non-ferrous metal smelting flue gas in this study. Results showed that the hierarchical Ag-SiO 2 @Fe 3 O 4 magnetic composites had favorable Hg 0 removal ability at low temperature. Moreover, the adsorption capacity of hierarchical magnetic composite is much larger than that of pure Fe 3 O 4 and SiO 2 @Fe 3 O 4 . The Hg 0 removal efficiency reached the highest value as approximately 92% under the reaction temperature of 150°C, while the removal efficiency sharply reduced in the absence of O 2 . The characterization results indicated that Ag nanoparticles grew on the surface of SiO 2 @Fe 3 O 4 support. The large surface area of SiO 2 supplied efficient reaction room for Hg and Ag atoms. Ag–Hg amalgam is generated on the surface of the composites. In addition, this magnetic material could be easily separated from fly ashes when adopted for treating real flue gas, and the spent materials could be regenerated using a simple thermal-desorption method.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2020
·Vol. 7
·期 6
·065309
·
IF 1.929
Ran Zhou,Haihong Ma,Zhengfa Zhou,Weibing Xu,Fengmei Ren,Chunhui Li
SiO2 particles were modified by γ-aminopropyltriethoxy silane (KH550) and γ-(2,3-epoxypropoxy)propyltrimethoxy silane (KH560) in sequence to prepare SiO2 particles with silicone-methoxy groups on surface (SiO2-s-Si(OCH3)3). X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA) were used to characterize the modified SiO2 particles. The SiO2-s-Si(OCH3)3 particles and tetramethoxysilane were used to co-cure hydroxyl silicone oil. The strong interfacial interactions between silicone rubber and fillers, which came from hydrolyzed SiO2-s-Si(OCH3)3 particles in situ reacting with hydroxyl silicone oil, had a great effect on the properties of composites. The mechanical properties, thermal conductivity, dielectric strength and volume resistivity of SiO2-s-Si(OCH3)3/silicone rubber composites were considerably higher than that of pristine SiO2/silicone rubber composites at the same content of SiO2, while the dielectric constant and dielectric loss tangent of SiO2-s-Si(OCH3)3/silicone rubber composites was lower than that of pristine SiO2/silicone rubber composites at the same content of SiO2.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Qiuyun Zhu,Xi Tang,Shasha Feng,Zhaoxiang Zhong,Jianfeng Yao,Zhong Yao
Severe air pollution causing by particulate matter and VOCs calls for multifunctional air purification media. Here, we report a novel bioinspired bead-on-string-like ZIF-8@SiO 2 composite nanofiber membrane, which has a synergistic promoting effect on particulate matter (PM) capture and gas pollutants adsorption. The flexible SiO 2 nanofiber membrane was fabricated by electrospinning, while zeolitic imidazolate framework-8 (ZIF-8) nanocrystals were grown on the nanofibers by controlling the crystallization by contra-diffusion. The resultant ZIF-8@SiO 2 composite membrane showed high removal efficiency of 99.96% for incense smoke which attributed to the ZIF-8 enhanced surface area and electrostatic interaction between beaded ZIF-8 nanocrystals and PM particles. Further, the uniformly loaded ZIF-8 nanocrystals with compatible pore size, large microporosity and specific surface area enhanced the formaldehyde adsorption efficiency to 79.53% in 2 h. The design of the ZIF-8@SiO 2 composite membrane with fascinating PM removal efficiency and excellent formaldehyde adsorption capacity would make it a promising medium for multicomponent air purification.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 11
·12017-12029
·
IF 3.056
Lv Yuancai,Huang Siyi,Huang Guofu,Liu Yifan,Yang Guifang,Lin Chunxiang,Xiao Gao,Wang Yonghao,Liu Minghua
Given their considerable solubility in water and potentially high toxicity to human health, organoarsenic compounds have become an emerging contaminant. Herein, a heterogeneous Fenton process mediated by SiO 2 -coated nano zero-valent iron (SiO 2 -nZVI) was employed to simultaneously remove the p -arsanilic acid ( p -ASA, a typical organoarsenic compound) and the released arsenic. The initial pH value significantly influenced on the degradation of p -ASA and at the optimal pH (3.0), p -ASA (10 mg L −1 ) could be completely oxidized to As(V), NH 4 + , and plentiful phenolic compounds such as phenol and p -hydroquinone via the cleavage of C–N and C–As bonds within 60 min in pure water. Meanwhile, although the formed lepidocrocite and magnetite on the surface of SiO 2 -nZVI significantly limited the reutilization, they played a vital role in the adsorption of the released As(V) and the residual arsenic levels in the effluent were as low as 0.031 mg L −1 , meeting both the drinking water standard of the World Health Organization (WHO) and the surface water standard of China (0.05 mg L −1 ). Furthermore, high-level dissolved organic matters (DOM) (> 2 mg C L −1 ) exhibited strong interference with both the oxidation of p -ASA and adsorption of arsenic, but the interference could be eliminated by increasing the SiO 2 -nZVI dosage or adding H 2 O 2 . Importantly, this system could completely remediate p -ASA in a short time and simultaneously avoid the secondary pollution caused by inorganic arsenic, which was significant for the remediation of organoarsenic pollutants in swine wastewater.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2023
·
IF 3.8
Pan Zhang,Aizhao Pan,Ke Yan,Jiannan Sun
CdTe quantum dots (QDs) reveal the prospect as temperature sensors for high-speed bearing rotating elements owing to their excellent temperature dependence of photoluminescence (PL) spectra. However, the poor PL peak wavelength stability of CdTe QDs limits its practical application. Herein, we fabricated a CdTe@SiO 2 /PVA hybrid film via a sol–gel process based on CdTe QDs. The peak wavelength of PL spectra of the CdTe@SiO 2 /PVA hybrid film increases linearly with the rising temperatures, which is similar to CdTe QDs. Significantly, the linear relationship between the peak wavelength of PL spectra of the CdTe@SiO 2 /PVA hybrid film and temperature in the heating process from room temperature to 85 °C is consistent with that in the colling process from 85 °C to room temperature. In contrast to CdTe QDs, the CdTe@SiO 2 /PVA hybrid film presents superior PL peak wavelength stability. Furthermore, the uniformity of the hybrid film is significantly improved than our previous preparation method of thin films . The excellent film-forming property of the CdTe@SiO 2 /PVA hybrids is effective to engineering application. The feasibility and accuracy of the CdTe@SiO 2 /PVA sensor are verified through the temperature monitoring test of bearing rotating elements.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Xiaoqing Zhang,Yuewen Shao,Kai Sun,Mengjiao Fan,Shu Zhang,Xun Hu
Nickel-based catalysts are widely used in hydrogenation of varied types of organics. However, the nickel catalyst, like Ni/SiO 2 , lacks selectivity for hydrogenation of C=C and C=O. This is undesirable in some scenarios, such as conversion of biomass-derived furfuryl alcohol (FA) to cyclopentanone (CPO), a fine chemical, in which the C=C in furan ring of FA needs to be retained. In this study, introduction of sulfur species to Ni/SiO 2 catalyst via loading NiSO 4 was adopted to inhibit hydrogenation of furan ring in FA, aiming to achieve conversion of FA to CPO via ring-opening route. The results indicated that NiSO 4 was reduced to Ni x S y , which further reacted with metallic Ni, forming Ni 3 S 2 species and introducing the acidic sites with high-strength. The co-existence of Ni x S y and metallic Ni species effectively hindered hydrogenation of furan ring in FA, reducing tetrahydrofurfuryl alcohol (THFA) yield from 97% over Ni/SiO 2 to 0 over the NiS x /SiO 2 catalysts and shifting the major product to CPO. Nonetheless, the enhanced acidic sites along with the introduction of NiSO 4 catalyzed polymerization of reaction intermediates, competing with the production of CPO. The acidic sites, however, facilitated hydrogenolysis of vanillyl alcohol to selectively produce (yield: 94.3%) in hydrogenation of vanillin. Characterization of hydrogenation of FA with in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) technique suggested the oxygen-containing functionalities in FA, instead of furan ring, could strongly adsorb on the NiS 10 /SiO 2 catalyst, enhancing rearrangement reaction to form CPO while suppressing hydrogenation of the furan ring.
研究领域:
催化化学
·
生物质转化
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）