Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 42
·13128-13138
·
IF 0
Juan Zhou,Feng Ren,Shaofeng Zhang,Wei Wu,Xiangheng Xiao,Ying Liu,Changzhong Jiang
Tailorable synthesis of plasmon enhanced catalysts with high solar-light harvesting and energy-conversion efficiency has attracted wide interest due to its scientific and technological importance. In this paper, novel SiO2–Ag–SiO2–TiO2 multi-shell photocatalysts with wide-spectral-response were systematically designed and controllably synthesized, where the SiO2 spheres were used as the cores, and the SiO2 interlayers coated on the Ag nanoparticle (NP) shells were used to separate the Ag from the TiO2 shell. The structures of the SiO2–Ag–SiO2–TiO2 multi-shell photocatalysts can be tailored by changing the thickness of SiO2 interlayers from 1 to 2, 5, 8, 12, and 20 nm, while the anatase N-doped TiO2 shells with visible light response are maintained at a thickness of 20 nm. The photocatalytic activity tests show that the enhanced photocatalytic efficiency under both ultraviolet (UV) and visible light irradiation is related to the existence of Ag NP shells and the thickness of SiO2 interlayers. The complicated coupling mechanisms between TiO2 and a plasmon are systematically discussed, and a clear physical picture for the complicated coupling processes is presented. The main reasons for the enhancement of the photocatalytic activity of the SiO2–Ag–SiO2–TiO2 multi-shell structures are the localized surface plasmon resonance (LSPR) effect and scattering effect induced by Ag NPs.
研究领域:
材料科学
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光催化技术
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纳米科技
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产品关联
DOI
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2017
·
IF 4.421
Xuqiang Ji,Wenling Zhang,Wenpeng Jia,Xiaoxia Wang,Yu Tian,Li Deng,Jingquan Liu
The cactus-like double-shell structured SiO 2 @TiO 2 microspheres (CDS SiO 2 @TiO 2 microspheres) with high dielectric properties were successfully fabricated and utilized as high-performance electrorheological (ER) fluids and microwave absorbing materials. The SiO 2 nanospheres with average diameters of 190 nm were synthesized by the hydrolysis of tetraethyl orthosilicate (TEOS), and used as the core for the first coating layer of TiO 2 achieved by sol-gel method. The final cactus-like TiO 2 layer was prepared via a hydrothermal method. The morphology of the resultant samples was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM). This novel CDS SiO 2 @TiO 2 microspheres based suspension exhibited improved ER properties compared to conventional bare SiO 2 spheres.
研究领域:
材料科学
·
物理学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Di Wang,Yun Tan,Huaxiu Xu,Xionglei Wang,Lina Yu,Zhixin Xiao,Jide Wang,Shimei Xu
A tough and fluorescent NC hydrogel was fabricated by introduction of SiO 2 @TiO 2 core-shell structure nanoparticles (NPs) into polyacrylamide (PAAm)/Laponite nanocomposite (NC) hydrogel. The photoluminescent and mechanical properties of the resultant PAAm/Laponite/SiO 2 @TiO 2 dual NC hydrogel were explored with respect to the shell thickness of SiO 2 @TiO 2 . The dual NC hydrogel emitted stable and bright blue photoluminescence (PL), when radiated at 350 nm. The emission wavelength was slightly shifted from 423 to 428 nm with the increasing of the shell thickness due to the surface interaction of SiO 2 @TiO 2 NPs and polymers. Besides, the compressive strength and compressive fracture energy of the PAAm/Laponite/SiO 2 @TiO 2 dual NC hydrogels were 7535.8 kPa and 5740.3 J/m 2 which increased by 19 and 21%, respectively, relative to the MLS@T 0 dual NC hydrogel. The tensile strength was 207.2 kPa at a strain of 730%. The dual crosslinking of SiO 2 @TiO 2 NPs and Laponite, as well as the dual nanocomposite structure were responsible for the enhanced mechanical properties.
研究领域:
材料科学
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化学工程
·
生物医学材料
✓ 已验证
产品关联
DOI
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Yaqi Zhang,Haoran Zhang,Shiwei Tian,Longfei Zhang,Wei Li,Wei Wang,Xuhuan Yan,Na Han,Xingxiang Zhang
The elimination of dye pollutants from wastewater is a significant concern that has prompted extensive research into the development of highly efficient photocatalytic membranes. A novel method was proposed to prepare photocatalysis-enhanced poly(acrylonitrile-methyl acrylate) (PAN-based) membranes in this study. In detail, the blended membrane containing SiO2@TiO2 nanoparticles with a shell–core structure was first prepared via thermal-induced phase separation. The SiO2 nanoshells were dissolved, and the released TiO2 nanoparticles migrated to the membrane surface during a simple hydrolysis process, which prevents the TiO2 nanoparticles from directly contacting or interacting with the polymer matrix. The hydrogen bonds bind the exposed TiO2 with the PAN membrane surface, resulting in the formation of the TiO2@HPAN hybrid membrane. The photocatalytic efficiency of the TiO2@HPAN membrane doubled compared with that of nonhydrolyzed membranes. In the presence of UV light, the hybrid membrane can degrade 99.8% of methylene blue solution in less than 2 h, compared to only 86.1% for the blended membranes. Further, the TiO2@HPAN membrane showed excellent photocatalytic activity for cationic dyes due to electrostatic attraction. Moreover, the high-flux recovery rate and recycling stability of the TiO2@HPAN membrane lead to an excellent antifouling property. The facile preparation method proposed in this work shows extraordinary potential for the development of highly efficient selective photocatalytic materials for cationic dyes to be used in wastewater treatment applications.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2024
·
IF 4.5
Wei Liu,Zuyang Zhang,Daoyin Liu
SiO 2 /TiO 2 core/shell particles are effective photocatalysts, whose performance strongly depends on TiO 2 film thicknesses. Fluidized bed atomic layer deposition (FBALD) can precisely control film thickness at the sub-nanometer scale. In this work, TiO 2 films with different thicknesses are deposited on SiO 2 particles via different ALD cycles at 180 °C in a fluidized bed reactor. TEM images indicate that complete and uniform nanoscale TiO 2 films (0.7–6.4 nm, corresponding to 5–50 ALD cycles) are formed on SiO 2 surface. The TiO 2 film with about 3.9 nm is found to exhibit the highest photocatalytic characteristics by degrading rhodamine-B (RhB) and tetracycline (TC), and the photocatalytic activity is further maintained above 90% after 6 cycles of photocatalytic reaction. Suitable TiO 2 film thickness shows minimal charge transfer resistance, resulting in enhanced photon adsorption and separation of electrons and holes, thus improving photocatalytic performance. This work provides an effective way to tune the photocatalytic performance via FBALD.
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
APPLIED ENERGY
·
2013
·
IF 4.781
Lei Miao,Li Fen Su,Sakae Tanemura,Craig A.J. Fisher,Li Li Zhao,Qing Liang,Gang Xu
Simultaneous antireflective and self-cleaning properties have been realized by depositing double-layered SiO 2 –TiO 2 coatings onto glass substrates using a combined sol–gel dip-coating process in which the two oxide layers were deposited in succession. The first layer is composed of a hybrid methyl-functionalized nanoporous SiO 2 material that provides on average a 6% anti-reflection gain. The degree of antireflectivity can be controlled by adjusting the thickness and refractive index by selecting suitable solvents and pore-forming agents in the coating mixture. The second layer is an ultrathin TiO 2 nanoporous layer deposited on top of antireflective layer. The high hardness of the TiO 2 top layer acts as a protection barrier toward mechanical damage and ensures the surface is self-cleaning. An average anti-reflectivity of 3.4% achieved over a spectrum range of 400–800 nm for the optimal SiO 2 –TiO 2 bilayers is obtained. It is found that a homogeneous pore size distribution in the SiO 2 layer introduced by using isopropanol as the solvent can compensate for the TiO 2 band edge absorption based on the optical interference that occurs between the two layers. These systems are easy to produce on a large scale at low cost and exhibit high mechanical and chemical durability. These materials are thus suitable for use as bifunctional antireflective and self-cleaning coatings for use as large substrates for solar cells.
研究领域:
材料科学
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光学涂层
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纳米技术
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可再生能源
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
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2020
·
IF 8.247
Fei Li,Ying Wang,Ri-Sheng Bai,Xiao-Xue Wang,Ma-Lin Li,Ji-Jing Xu
The issue of cathode passivation during cycling resulting in rapid capacity fading and premature battery death is a major challenge that hinders the applications of lithium–oxygen (Li–O 2 ) batteries. Here, a facile strategy of introducing a functional separator based on flexible amination SiO 2 /TiO 2 inorganic woven film (STON WF) is proposed to suppress the cathode passivation problem. The by-products, i.e. HCOOLi, CH 3 COOLi and Li 2 CO 3 can be selectively adsorbed on the STON WF separator preferably compared with the cathode and further proved by the density functional theory (DFT) calculations. Thus, benefiting from the separator, the Li–O 2 cells with super P carbon and catalyst-free cathode show enhanced electrochemical performance (5645 mA h g −1 at a current density of 200 mA g −1 ), good rate capability (discharge voltage of 2.43 V at a current density of 1.5 A g −1 ) and especially superior cycle stability up to 268 cycles. These findings present a promising approach to prevent the premature battery death.
研究领域:
电化学
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能源材料
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纳米材料
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表面化学
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电池技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Lihong Wu,Yifeng Zhou,Wangyan Nie,Linyong Song,Pengpeng Chen
In this study, teardrop-shaped SiO 2 /TiO 2 nanoparticles (TST-NPs) with core–shell structure were fabricated from tetraethoxysilane (TEOS) and tetrabutyl titanate (TBT) by sol–gel method. And these nanoparticles were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and UV–vis spectroscopy. Photocatalytic activity of teardrop-shaped SiO 2 /TiO 2 nanoparticles after calcination (CST-NPs) was studied towards degradation of methylene blue under sunlight irradiation. The result showed that CST-NPs possessed good photocatalytic activity. The photocatalytic mechanism was also studied by adding different capture agent. Results showed that addition of 0.003 M of I − decreased the degradation of MB more than same amount of Ag + , indicating that the photogenerated holes may play a more essential role than photoinjected electrons in the oxidation of MB.
研究领域:
材料科学
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纳米技术
·
光催化
·
环境化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2013
·
IF 2.112
Xiaohai Bu,Yuming Zhou,Man He,Zhenjie Chen,Tao Zhang
Optically active silica/titania/substituted polyacetylene (SiO 2 /TiO 2 /SPA) multilayered core–shell nanocomposite was successfully prepared by the combination of subsequent surface titania deposition and polymer grafting on the bare silica nanosphere. The chiral amino acid-based SPA copolymer serving as the organic shell was optically active and adopted a predominately single-handed helical conformation. The SiO 2 /TiO 2 /SPA nanospheres were characterized by Fourier transform infrared spectroscopies (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) to record the formation of the multilayered architecture and the results clearly showed that the inorganic/organic hybrid nanoparticles exhibited hierarchical multilayered core–shell construction. The SPA outer shell experienced an enhancement in thermal stability and still remained considerable optical activity after grafting to the SiO 2 /TiO 2 nanosphere. The SiO 2 /TiO 2 /SPA nanocomposite had an infrared emissivity value ( ɛ = 0.548) at the wavelength of 8–14 μm which was much lower than each of its components. The reduced infrared emissivity values proved that the strengthened interfacial interactions originating from the coating SPA had an effective synergistic effect with the semiconductive anatase TiO 2 nanoparticles on silica sphere in lowering the infrared emissivity value.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2014
·Vol. 97
·期 6
·1944-1951
·
IF 2.428
Weibo Chen,Zhijun Ma,Xuanzhao Pan,Zhongliang Hu,Guoping Dong,Shifeng Zhou,Mingying Peng,Jianrong Qiu
Structural design is of great importance to the performance of photocatalysts in environmental remediation. Therefore, micro/nanofibrous morphology and nanoporous local structures have been found to be beneficial to improve the photocatalytic activity. In this investigation, we report the design and fabrication of flexible and thermal stable nanoporous SiO 2 –TiO 2 composite fibers as efficient photocatalysts. Combining electrospinning and modified Stöber techniques, core-shell and mesoporous SiO 2 fibers with high flexibility were fabricated and employed as the scaffold for supporting TiO 2 nanoparticles. A nanoporous shell of TiO 2 nanoparticles was then muffled over the SiO 2 fibers to form core@dual-shell SiO 2 –TiO 2 composite fibers with hierarchically porous structure, which were conveniently patterned into a nonwoven, recyclable film. This nonwoven film exhibits better photocatalytic activity for Rhodamine B degradation under UV irradiation compared with some other TiO 2 -based materials reported in recent years.
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
Journal of the Iranian Chemical Society
·
2014
·Vol. 12
·期 5
·765-770
·
IF 1.406
Xu Zhaozan,Zhu Jiang,Liao Xiaoqing,Ni Haitao
The PET/SiO 2 /TiO 2 composites were prepared via in situ polymerization. The effect of nano SiO 2 and TiO 2 content on crystallization behavior and thermal stability of PET was investigated by differential scanning calorimeter (DSC), X-ray diffraction (XRD), and thermogravimetry. The morphology of SiO 2 and TiO 2 particles and their dispersion in PET were studied by scanning electron microscope. The addition of SiO 2 and TiO 2 nano particles affects the thermal stability and flame property of PET and the effect depends on their content. It also affects the perfect degree of PET crystal. From DSC data analysis, crystallization temperature and enthalpy value reduce with SiO 2 and TiO 2 nano particles, but they increase with increasing SiO 2 and TiO 2 loading. A low content of SiO 2 and TiO 2 nano particles will decrease the degree of crystallinity, but enough amounts of them will increase the degree of crystallinity of PET because of heterogeneous nucleating effect of the particles. The degree of crystallinity calculated based on XRD data also shows this phenomenon. From XRD results analysis, it is also found that the average grain size of PET decreases with a little of SiO 2 and TiO 2 nano particles, but it increases with increasing content of particles.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Meiqi Chang,Yanhua Song,Jie Chen,Lei Cui,Zhan Shi,Ye Sheng,Haifeng Zou
A novel multifunctional core–shell, yolk–shell SiO2@TiO2:Eu3+/Sm3+ and hollow TiO2:Eu3+/Sm3+ structures were successfully synthesized. The relationship between morphology/ions doping and multifunctional properties including photoluminescence and photocatalysis has been discussed in detail for the first time using systematic characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL), ultraviolet–visible light (UV-vis) analysis, Fourier transform infrared (FT-IR) spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, and X-ray photoelectron spectroscopy (XPS). Upon ultraviolet (UV) excitation, the products show the characteristic red and orange–red emission lines of Eu3+ and Sm3+, respectively. In addition, Judd–Ofelt intensity parameters (Ω2, Ω4) were used to investigate the symmetry and coordination state of Eu3+ ions in the products with different morphologies. The relative luminescence intensities were in the following order: yolk–shell > core–shell > hollow structure. This phenomenon can be ascribed to the unique yolk–shell configuration, which possesses appropriate interior cavity used for multiple reflections and scattering, allowing for more-efficient utilization of the light. Moreover, compared with yolk–shell and hollow structure, the core–shell spheres exhibit excellent photoactivity for the degradation of MO, because the existence of Ti–O–Si bonds increases the surface acidity of the sample, thereby activating the oxidation reaction. In addition, the electron activation in the TiO2 matrix can be facilitated through intermediate oxygen atoms. Moreover, products doped with different rare-earth (RE3+) ions exhibited distinguishable photocatalytic performance. The surfactant-free method provides a promising route toward the development of multifunctional materials for many applications in photocatalysis and PL.
研究领域:
材料科学
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光学
✓ 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）