JOURNAL OF ALLOYS AND COMPOUNDS
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2023
·
IF 6.2
Han Zhang,Sijia Sun,Hao Ding,Ying Chen
Using amorphous SiO 2 (A-SiO 2 ) and tetrabutyl titanate (TBOT) as raw material, a composite photocatalyst with surface loaded quantum dot size TiO 2 (A-SiO 2 /TiO 2 , AST) was prepared. The degradation of tetracycline hydrochloride as well as mechanism of performance improvement by A-SiO 2 were investigated. The TiO 2 on the composite was anatase with a content of 9.96 wt% and a size of 7–8 nm (quantum dot level). TiO 2 was uniformly distributed and was closely bonded at the interface by chemical bonds. The degradation rate of AST was 95% after 60 min UV exposure, which was comparable to pure nano-TiO 2 . The particle size of TiO 2 in AST was reduced from 20–50 nm to 7–8 nm comparing with pure nano-TiO 2 and changed from a highly agglomerated to a well-dispersed state due to abundant hydroxyl groups on A-SiO 2 surface. TiO 2 bandgap width increased from 3.25 eV to 3.39 eV. These led to the exposing of active sites on TiO 2 and significantly increased photogenerated carrier separation efficiency. This study provides a feasible and simple method to improve TiO 2 nanoparticles’ photocatalytic activity, reduce the usage and achieve recycling to cut the application cost by surface coated.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Yihui Ma,Fangli Zhang,Kun Chen,Yue Zhou,Zhaohui Wang,Zhaoliang Cui
As a new separation technology, membrane condensation requires simple equipment and mild operating conditions and has wide application potential and value in the process of water vapor recovery and chemical concentration and recovery. In this paper, we have proposed a new application process to incorporate nano-SiO2 into ECTFE membranes and apply them in the membrane condensation process. The fabrication of ethylene-chlorotrifluoroethylene copolymer (ECTFE)/SiO2 hybrid membranes is performed by incorporating hydrophobic nano-SiO2 during ECTFE membrane preparation, with varying ECTFE/SiO2 compositions achieved through SiO2 dosage adjustments. It can be found that SiO2 can change the structure of membrane during the process; hence, the impact of SiO2 removal after membrane formation on membrane performance was evaluated. SiO2 removal was conducted using a 1 mol/L hot alkali solution with continuous agitation for 24 h. A maximum water recovery rate of 24% (adequate for industrial water self-sufficiency) was attained at 2 wt % SiO2. Compared with the original membrane, the addition of hydrophobic nano-SiO2 significantly enhances the condensation performance of the ECTFE membrane.
研究领域:
化学工程
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材料科学
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环境工程
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Chaofeng Lv,Jincui Ren,Yuting Duan,Yisheng Wu,Xinyi Li
To improve the oxidation resistance of alumina–carbon refractories, SiO 2 –B 4 C-glass composite coating was prepared by slurry brushing method on the surface of refractories. Effect of SiO 2 content on the oxidation resistance of the coating was studied. Oxidation resistance mechanism and failure reason of the SiO 2 –B 4 C-glass coating were discussed. Results showed that introducing SiO 2 could increase viscosity activation energy and elevate the glass layer's viscosity at high temperature. With the increase of SiO 2 content, the glass viscosity at high temperature gradually increased. When SiO 2 content was too low, the glass exhibited smaller viscosity and larger fluidity, so the glass layer was easy to be washed away. When SiO 2 content was too high, the glass phase with high viscosity and low fluidity could not uniformly cover on the surface of alumina–carbon refractories. The composite coating with SiO 2 content of 55 wt% exhibited excellent oxidation resistance, which could effectively protect alumina–carbon refractories at 800 °C for 100 h with weight loss of only −1.721%. Excellent oxidation resistance of the coating mainly depended on the glass layer with good self-healing ability. With the extension of oxidation time, the coating thickness decreased, leading to the relatively poor self-healing ability and reduced weight gain rate of the coating.
研究领域:
材料科学
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无机化学
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产品关联
DOI
高影响因子
POLYMER SCIENCE SERIES B
·
2024
·
IF 1
Le Liu,Yang Wentong,Huang Xiaoling,Deng Qingsheng,Yu Deyu,Zhang Hongwen,Jiang Yan
Abstract In this study, VO x was prepared by oxalic acid and vanadium pentoxide under nitrogen atmosphere and SiO 2 was grown on the surface of VO x . Block copolymer (PCL- b -PDMS- b -PCL) was synthesized by hydroxy terminated poly(dimethylsiloxane) and caprolactone, and the composite material containing inorganic particles was obtained by blending VO x /SiO 2 with PCL- b -PDMS- b -PCL. The porous film was constructed by breathing pattern method, and the supersmooth surface was obtained by injecting lubricating oil into the porous film. The composite was tested by Fourier transform infrared spectroscopy, hydrogen NMR spectroscopy, scanning electron microscopy, contact angle and anti-bacterial adhesion. The results showed that PCL- b -PDMS- b -PCL was successfully synthesized, and the prepared composite material containing inorganic particles had excellent superslippery properties after oil injection, and the sliding angle was 2°.
研究领域:
材料科学
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表面工程
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化学合成
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DOI
高影响因子
SURFACE ENGINEERING
·
2019
·
IF 2.229
J. P. Lu,L. Chen,R. G. Song
The surfaces of SiO2 ultra-fine particles with different sizes have been modified by γ-(2, 3-epoxypropoxy)propytrimethoxysilane (KH-560) silane coupling agent. Then the homogeneous fluoropolymer/SiO2 composite coatings have been successfully prepared on mild steel substrates. The surface grafting of KH-560 on SiO2 particles was detected by means of Fourier transform infrared spectroscopy, thermo gravimetric analysis and transmission electron microscopy. The surface morphologies and corrosion resistance of fluoropolymer/SiO2 composite coatings were characterised by field emission scanning electron microscopy, potentiodynamic polarisation as well as electrochemical impedance. The results showed that KH-560-modified SiO2 particles can decrease agglomeration effectively, and the particles play a beneficial role in improving the corrosion resistance of the coated steel significantly. There exists an obvious effect of SiO2 particles size on the corrosion resistance of fluoropolymer/SiO2 composite coatings. Also, the SiO2 particles with diameter of 150 nm are of the best effect among all particle sizes.
研究领域:
材料科学
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腐蚀与防护
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DOI
高影响因子
Materials Research Express
·
2018
·Vol. 5
·期 10
·105506
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IF 1.151
Zhao Yangzhou,Yuan Weifeng,Zhao Chaoyang,Gu Bin,Hu Ning
In this work, a fabrication process was developed to incorporate nano-SiO2 particles into poly(vinylidene fluoride) to make piezoelectric films. Experimental tests show that the piezoelectricity of the nanocomposites can be improved if the weight fraction of the additive increases within a specific range. Optical microscope images indicate that the presence of SiO2 particles can reduce the average diameter of the spherulites and increase the amount of heterogeneous nucleation sites in the PVDF matrix. In the fabrication process, stretching is used to enhance the α-β-phase transformation and orient the dipoles of the β-phase. From the experiment in which the nanocomposite films were affixed onto a vibrating beam for electricity harvesting, it was found that the output voltages of the films are dependent on not only the amplitude but also the frequency of the beam's vibration. This finding may have great potential in the field of energy harvesting using flexible piezoelectric films.
研究领域:
材料科学
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能源工程
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
Qi Jiang,Jian Huang,Baoguo Ma,Zhengcai Yang,Ting Zhang,Xin Wang
TiO 2 @SiO 2 composite microspheres (TS) were prepared by the deposition of TiO 2 on the raspberry-like SiO 2 @polystyrene microspheres (PSS). The hollow microspheres with hierarchical microtopography possess both improved photocatalytic activity and stabilized TiO 2 particle structure. The results of energy dispersion spectrum (EDS) mapping, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) showed that after calcination, anatase TiO 2 nanoparticles has formed on the raspberry-like PSS template with preferred deposition among interstitials of the drupelet-like structure. The thermal degradation of the polystyrene (PS) core during calcination led to the hollow microspheres. The photocatalytic experiments indicated that the raspberry-like TiO 2 @SiO 2 composite microspheres (TS1-TS3) had higher photocatalytic efficiency than the smooth ones (TS0), due to the hierarchical and hollow structure. The sample TS2 prepared with a moderate ammonia concentration (3 %) not only had relatively more intact hollow spherical structure, but also enhanced photocatalytic activity. The hollow TiO 2 @SiO 2 composite microspheres (TS3) prepared with 4 % ammonia showed the best photocatalytic efficiency. However, the higher ammonia concentration made the drupelet-like structure unstable and the microspheres tend to disintegrate. The raspberry-like microstructure showed a protective effect on the loaded TiO 2 , which resulted in better recyclability with persistent photocatalytic activity. The hierarchical composite microspheres shed light on the potential effective utilization strategy of nano-photocatalyst.
研究领域:
材料科学
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化学
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纳米技术
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环境科学
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产品关联
DOI
高影响因子
ACS Omega
·
2024
·
IF 3.7
Qingjing Liu,Ruisheng Wang,Ranjia Li,Xiaosheng Wang,Suoqi Zhao,Changchun Yu
Mn–Na2WO4-based catalysts with different supports were prepared using the incipient wetness impregnation method and evaluated for their oxidative coupling of methane (OCM) reaction performance. The results demonstrated that the SiO2- supported catalyst exhibited the best catalytic performance, and the introduction of H2O further enhanced its activity. Under the conditions of a feed gas mixture of CH4/O2/H2O = 6:1:24 at 800 °C and atmospheric pressure, the CH4 conversion and C2+ selectivity over the Mn–Na2WO4/SiO2 catalyst increased from 28.4% and 77.4% (without H2O) to 33.2% and 84.9%, respectively. In contrast, the catalytic activity using TiO2 and MgO supports drastically declined. Characterizations using X-ray diffraction (XRD), in situ infrared spectroscopy (In-situ IR), X-ray photoelectron spectroscopy (XPS), hydrogen temperature-programmed reduction (H2-TPR), and oxygen temperature-programmed desorption (O2-TPD) revealed that the introduction of steam not only served as a diluent to decrease the partial pressures of the reactants CH4 and O2, thereby reducing deep oxidation reactions in the gas phase, but also interacted with surface oxygen species (O22–) and silica to form adjacent surface-bonded disilanol free radicals Si–OIH. This interaction facilitated the dehydrogenation and coupling of two methane molecules on the catalyst surface, resulting in the generation of C2+ products, significantly enhancing the catalytic activity and selectivity of OCM.
研究领域:
化学工程
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催化科学
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产品关联
DOI
PubMed
高影响因子
FUEL
·
2024
·
IF 6.7
Xiao Yang,Zhuwei Yang,Linsen Li,Zhao Jiang,Guangxu Cheng
Dry methane reforming (DRM) represents a highly promising approach to greenhouse gas conversion (CO 2 and CH 4 ) to valuable byproducts. However, severe carbon deposition and catalyst deactivation inhibit large-scale applications. The work designed new catalysts with a yolk-shell structure using the water-in-oil microemulsion method. The catalysts were composed of a yolk-shell structure, with Ni-M as the active point and silica as the shell. The catalytic performance evaluation indicates that the Ni-M @SiO 2 catalysts show higher CH 4 and CO 2 conversion compared with the Ni@SiO 2 and conventional catalysts at 750 ℃, suggesting the yolk-shell structure and added M species enhance the DRM activity. The XRD, HRTEM, XPS, BET, H 2 -TPR, and CO 2 -TPD analysis confirmed the existence of yolk-shell configuration and evident electronic effect among Ni, M species, and SiO 2 . The long term measurements indicate that the added M species also bring higher carbon deposition tolerance for DRM, where Ni-Ce@SiO 2 and Ni-Zr@SiO 2 exhibit good structural and catalytic stability for DRM over 100 h. Through XRD, TEM, and TGA characterizations of the exhausted catalysts, it is determined that the coke deposition resistance of the catalyst is improved as a result of increased oxygen mobility and enhanced Ni dispersion on the catalytic surface, both of which are enhanced by the added Ce species. The structural analysis of the spent catalysts indicates that the tolerance of carbon deposition is improved by the yolk-shell samples. This study can offer valuable insights for the development of Ni-based catalysts with exceptional carbon deposition capability for DRM.
研究领域:
催化
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化学工程
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材料科学
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DOI
高影响因子
Silicon
·
2025
·
IF 3.3
Yang Yonghui,Fan Chao,Yang Pengchen,Liu Zhanwei,Yan Hengwei
This study investigated the effect of aluminum oxide (Al 2 O 3 ) additives on the properties of NaF-AlF 3 -SiO 2 melts. The liquid-phase line temperature was determined through thermal analysis, while the solubility and volatilization loss of silicon dioxide (SiO 2 ) were evaluated using the rotating quartz disk method and volatilization experiments. The dissolution mechanism of Al 2 O 3 in the melt was explored through thermodynamic analysis and experimental validation. The results indicated that Al 2 O 3 addition significantly decreased liquid-phase line temperature, enhanced SiO 2 solubility, and reduced volatilization losses. These findings provide a theoretical basis for optimizing the electrolysis process of Al–Si alloys, which contribute to improved melt performance, enhanced energy efficiency, and reduced volatilization losses, thereby promoting increased efficiency in industrial applications.
研究领域:
冶金学
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材料科学
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Haohan Wang,Jinghuang Lin,Jian Cao,Junlei Qi
Joining is an indispensable process for expanding the application of ceramics and composites. Recently, glasses have been extensively explored for ceramic/composite joining owing to their unique functional needs. However, the difficulty in detecting amorphous materials and lack of enthalpy data make the interfacial reaction mechanism challenging to investigate. In this study, the interfacial reaction mechanism of joints of SiO 2f /SiO 2 composite-brazed bismuth glass was thoroughly explored. SiO 2 was dissolved from the matrix and used throughout the brazing process. In the initial stage, silica reacts with the brazing glass to form Bi 4 (SiO 4 ) 3 . Then, owing to the decomposition of Bi 4 (SiO 4 ) 3 , the silicate glass replaced the bismuth glass. Finally, some precipitation of SiO 2 occurred at the brazing seam owing to an entropy–enthalpy dominating mode. This study may instigate the design of brazing glasses for joining SiO 2f /SiO 2 composites.
研究领域:
材料科学
·
焊接工程
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产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2019
·Vol. 91
·期 3
·431-440
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IF 1.986
Zhang Cui,Shi Yan,Fu Zhifeng
We present an effective and environmental-friendly pathway to prepare SiO 2 hollow particles using Na 2 SO 4 particles as templates, which involved sol-gel silica coating on surface of the templates and subsequent removal of the Na 2 SO 4 templates by water-dissolution. Further, SiO 2 /TiO 2 double-shell hollow particles were prepared by coating TiO 2 on the surface of the hollow SiO 2 particles. The morphologies and structures of the synthesized hollow particles were characterized using SEM, TEM, XRD, FTIR, BET, and UV. The sizes and shapes of the hollow particles can be controlled by using Na 2 SO 4 templates with different sizes and shapes. The sizes of hollow particles were in the range from 500 nm to 15 μm. By changing the concentration of silicon precursor, the shell thickness of hollow SiO 2 particles can be controlled in the range of 25–200 nm. In addition, SiO 2 /TiO 2 double-shell hollow particles showed better photocatalytic degradation of Rhodamine B than that of hollow TiO 2 particles and solid TiO 2 particles.
In this study, we have successfully fabricated hollow SiO 2 particles with different shapes and size, as well as hollow SiO 2 /TiO 2 double-shell particles via a facile and environmentally friendly method employing water-soluble inorganic Na 2 SO 4 particles as template. The preparation process involved sol-gel silica and titania coating on surface of the template and followed by water-dissolution removal of the Na 2 SO 4 template.
研究领域:
材料科学
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纳米技术
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）