MATERIALS RESEARCH BULLETIN
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2013
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IF 1.913
Houbao Cao,Pingfan Du,Lixin Song,Jie Xiong,Junjie Yang,Tonghai Xing,Xin Liu,Rongrong Wu,Minchao Wang,Xiaoli Shao
In this paper, core/sheath TiO 2 /SiO 2 nanofibers with tunable sheath thickness were directly fabricated via a facile co-electrospinning technique with subsequent calcination at 500 °C. The morphologies and structures of core/sheath TiO 2 /SiO 2 nanofibers were characterized by TGA, FESEM, TEM, FTIR, XPS and BET. It was found that the 1D core/sheath nanofibers are made up of anatase–rutile TiO 2 core and amorphous SiO 2 sheath. The influences of SiO 2 sheath and its thickness on the photoreactivity were evaluated by observing photo-degradation of methylene blue aqueous solution under the irradiation of UV light. Compared with pure TiO 2 nanofibers, the core/sheath TiO 2 /SiO 2 nanofibers performed a better catalytic performance. That was attributed to not only efficient separation of hole–electron pairs resulting from the formation of heterojunction but also larger surface area and surface silanol group which will be useful to provide higher capacity for oxygen adsorption to generate more hydroxyl radicals. And the optimized core/sheath TiO 2 /SiO 2 nanofibers with a sheath thickness of 37 nm exhibited the best photocatalytic performance.
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高影响因子
MATERIALS LETTERS
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2013
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IF 2.224
Rong Li,Shidong Ji,Yamei Li,Yanfeng Gao,Hongjie Luo,Ping Jin
Rectangular and plate-like VO 2 (M)@SiO 2 nanoparticles were fabricated by a combination method of hydrothermal synthesis and post annealing process. Rectangular VO 2 (B) nanoplates of 20–30 nm in thickness were hydrothermally synthesized, and VO 2 (B)@SiO 2 core–shell structure was formed using a modified Stober method. Protected by inert SiO 2 shell, after post annealing the VO 2 (B)@SiO 2 was transformed to VO 2 (M)@SiO 2 without deteriorating its original plate-like morphology. Much interestingly, numerous nanopores were formed inside VO 2 (M)@SiO 2 nanoparticles due to the difference in density between VO 2 (B) and VO 2 (M), which contributes to higher optical transmittance and thermal insulation . Thermochromic foils were fabricated using the core–shell nanoparticles, showing promising potential for smart window.
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JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
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2015
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IF 2.128
Chuan-Yang Shang,Wei-Xun Li,Feng Jiang,Rui-Feng Zhang
ZnO nanowires/macroporous SiO 2 composites were used as a new type of microwave absorbing support to immobilize Candida rugosa lipase (CRL). Under microwave irradiation the immobilized lipase was used to catalyze esterification of phytosterol and oleic acid for the synthesis of phytosterol esters. A great improvement of the catalytic activity was found in the systems in which composited ZnO nanowires were present. The microwave absorbing properties of ZnO nanowires have been proved to be helpful for the synergistic effect between microwave irradiation and enzyme catalysis. The immobilized CRL showed higher thermal stability at 55 °C under microwave irradiation than conventional heating. A maximum molar conversion of 95.4% under microwave irradiation was achieved under the optimal condition: 0.1 M phytosterol, 0.2 M oleic acid, water activity ( a w ) of 0.11, reaction temperature at 50 °C and reaction time of 1 h.
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Journal of Materials Chemistry C
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2013
·Vol. 1
·期 39
·6355-6363
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IF 0
Youlin Zhang,Xianggui Kong,Bin Xue,Qinghui Zeng,Xiaomin Liu,Langping Tu,Kai Liu,Hong Zhang
Applying the Stöber method to directly coat noble metal nanoparticles (NPs) such as gold (Au) and silver (Ag) NPs with silica shells presents challenges, since the noble metal NPs are not stable in alcoholic solution and have low chemical affinity for silica. This paper describes a method which uses 11-mercaptoundecanoic acid (MUA) as a linker molecule between the silica shell and the noble metal NPs. MUA binds strongly to the surface of the NPs via a metal–S bond by replacing the standard capping agents on the surface of the NPs. Upon MUA stabilization, the NPs can be transferred into alcohol solution and show chemical affinity for silica. The MUA-modified NPs can be directly coated with thickness controlled, smooth and homogeneous silica shells via the standard Stöber method by varying the amount of tetraethoxysilane (TEOS). Compared with methods reported in the literature for the coating of such particles, this method can not only be used to successfully coat citrated-stabilized Au or Ag NPs, but can also be extended to encapsulate oleylamine (OA)-stabilized Au NPs and cetyltrimethylammonium bromide (CTAB)-stabilized Au nanorods (NRs) by using MUA to displace the original ligand on the surface of the NPs. Additionally, the obtained metal@SiO2 core–shell NPs have been successfully applied as plasmonic nanoantennas for fluorescence enhancement in metal@SiO2@fluorophore NPs.
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ELECTROCHIMICA ACTA
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2014
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IF 4.086
Yunyun Zhai,Ke Xiao,Jianyong Yu,Bin Ding
ABSTRACT The performance of lithium ion battery based on electrospun nanofibrous membranes has gained a great deal of attention in the past decades, but the intrinsic low mechanical strength and large pore size of electrospun membranes limit their battery performance. To overcome this limitation, a powerful strategy for designing, fabricating and evaluating silica nanoparticles coated polyetherimide-polyurethane (SiO 2 /PEI-PU) nanofibrous composite membranes is easily developed via electrospinning followed by a dip-coating process. Benefiting from the high porosity, interpenetrating network structure and synergetic effect of PU, PEI and SiO 2 nanoparticles, the as-prepared composite membranes exhibit high ionic conductivity (2.33 mS cm −1 ), robust tensile strength (15.65 MPa) and improved safety (excellent thermal resistance and flame retardant property). Additionally, the as-prepared composite membranes possess relatively narrow pore size distribution with average pore size of 0.58 μm after coating SiO 2 nanoparticles, which plays an important role in hindering the micro-shorting and mitigating self-discharge. Significantly, the SiO 2 /PEI-PU membranes based Li/LiFePO 4 cell exhibits more excellent cycling stability with capacity retention of 98.7% after 50 cycles at 0.2 C rate and better rate capability compared with the Celgard membrane based cell. The results clearly demonstrate that this is a promising separator candidate for next-generation lithium ion batteries, which may represent a significant step toward separators with improved performance.
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JOURNAL OF MATERIALS SCIENCE
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2017
·Vol. 52
·期 21
·12806-12817
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IF 2.599
Zhong Xi,Zhou Yuming,He Man,Tong Yuan,Fan Lidan,Cai Zhilan
In this study, a simple, convenient and green approach for the preparation of organosiloxane-coated SiO 2 /CeO 2 (SiO 2 /CeO 2 /poly(VTMS)) with multilayered hierarchical structure is demonstrated by consecutive surface cerium deposition and organosiloxane grafting on the bare silica spheres. The results of the UV–Vis spectrum and photoluminescence analysis suggest that the fillers may be potentially applied in UV absorbers and bioimaging materials. Moreover, the optical diffusers based on the multilayered spheres can be prepared via a solvent-free UV curing process and exhibit enhanced properties like suitable light transmittance, good diffusion capacity and low-incident angle dependence, which are critical for the optical diffusers. In addition, when the concentration of the fillers was 15 wt%, the optical diffusers presented superior light-diffusing properties among all the as-prepared samples. Thus, the films based on the SiO 2 /CeO 2 /poly(VTMS) with multilayered hierarchical structure may open up new possibilities in applications as multifunctional light diffusion films in liquid crystal displays.
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SEPARATION AND PURIFICATION TECHNOLOGY
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2016
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IF 3.299
Haiye Wang,Xinzhen Zhao,Chunju He
The polydimethylsiloxane modified silica (SiO 2 -g-PDMS) nanoparticles with hydrophilic core and hydrophobic shell are employed for the hybridization modification of PVDF ultrafiltration membrane to improve the separation and antifouling performances. The results suggest the modified SiO 2 -g-PDMS nanoparticles exhibit improved dispersion and significant amphiphilic characteristics, and the wetting properties of membrane surface and mimetic matrix of hybrid PVDF membranes are distinctly different with the contact angle values at 105° and 15°, respectively. In addition, the added SiO 2 -g-PDMS nanoparticles significantly improve the fouling repulsion and fouling release properties of hybrid PVDF membranes, the anti-adsorption ability and water flux recovery ratio (FRR-W) of hybrid PVDF membranes to the two typical pollutants of bovine serum albumin (BSA) and humic acid (HA) have been significantly improved. This article aims to provide a simple way to improve the antifouling performance of PVDF ultrafiltration membrane with dual-mode multi-functional modifier.
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Solar RRL
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2017
·Vol. 1
·期 12
·1700151
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IF 0
Xiaoman Zhang,Jialei Liu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Qingwen Tian,Yuena Meng,Sixin Wu,Aocheng Cao,Canbin Ouyang
Metallic nanoparticles (NPs) exhibit a surface plasmon resonance (SPR) and can be incorporated into perovskite solar cells (PSCs) to improve cell performance. However, the incorporation of Au NPs in bulk films of PSCs requires large concentration to keep interval distance and would cause worse device performance. In this work, a universal strategy for significant increasing power conversion efficiency (PCE) of PSCs through incorporating high aspect ratio Au nanorods (NRs)@SiO 2 into perovskite/spiro-OMeTAD interface is demonstrated. The key feature of this approach is that we can take advantage of the SPR at a lower concentration and the Au NRs have larger light scattering section than AuNPs. It is found that the SPR and scattering effect of Au NRs lead to a broad enhancement of photon absorption. Furthermore, a superior enhanced charge separation process in the Au NRs incorporated device is also observed. Benefitting from this cooperative plasmonic effect of Au NRs in optical and electrical aspects, both short-circuit current density and open-circuit voltage are improved, resulting in the new device delivering a PCE up to 17.39% from 14.39%. This result further supports that Au NRs can play a more effective SPR effect at perovskite/spiro-OMeTAD interface, rather than incorporating them into bulk films.
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SURFACE & COATINGS TECHNOLOGY
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2017
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IF 2.589
Xue-Ling Wei,Na Li,Wen Jun Yi,Li-Jun Li,Zi-Sheng Chao
The super-hydrophobic (SH) porous ceramics material with good stability was successfully prepared via the hydrothermal growth of CeO 2 micro/nano-structure and the subsequent dip-coating of low surface energy substance 1H,1H,2H,2H-perfluorodecyltriethoxysilane (PFDTES) over the surfaces of ZrO 2 -SiO 2 porous ceramics substrate. The surface morphology , chemical composition and wettability of material were investigated by means of SEM, EDS, XRD , FT-IR, and contact angle measurement. It was found that a layer of CeO 2 nano-flowers had been attached over the surfaces of ZrO 2 -SiO 2 porous ceramics substrate, using the optimized concentration of CeNO3 precursor, and after the grafting of PFDTES, the super hydrophobicity of the obtained material was achieved, with the water contact angle being as high as 162° and sliding angle being approximately 0°. Particularly, the super hydrophobicity was found to occur also in the pores of the obtained material. The obtained material was found to possess the significantly large thermal and chemical stabilities.
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高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2016
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IF 2.567
Bing Xue,Lei Hui,Huaqin Yang,Yulai Zhao,Linxi Hou,Wei Li
A macroporous SiO2 (Macro-SiO2), which has uniformed macropores, an open-framework structure, and thin walls, was synthesized to support Ziegler–Natta catalysts. The immobilization behaviors of the Ziegler–Natta catalysts inside the Macro-SiO2 were investigated. Notable agglomerations of δ-MgCl2/titanium complex were observed because of the unconstrained environment of the Macro-SiO2. A highly superficial Ti content and a heterogeneously chemical structure of Ti active sites were thus achieved inside the Macro-SiO2. The ethylene polymerization results revealed that the Macro-SiO2/MgCl2/TiCl4 exhibited much higher catalytic activity (i.e., 12.1 × 106 g PE·(mol Ti·h)−1 or 17.8 × kg PE·(g cat·h)−1) than that of the traditional 955-SiO2 supported catalyst (i.e., 2.0 × 106 g PE·(mol Ti·h)−1 or 2.7 × kg PE·(g cat·h)−1). Finally, the fragmentation behavior of Macro-SiO2/MgCl2/TiCl4 was investigated during the polymerization. This unconstrained environment of Macro-SiO2 afforded fewer resistances to the diffusion of reactants and also the polymer growth.
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JOURNAL OF CATALYSIS
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2016
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IF 7.354
Junjie Su,Zhengpai Zhang,Donglong Fu,Da Liu,Xin-Chao Xu,Bianfang Shi,Xu Wang,Rui Si,Zheng Jiang,Jing Xu,Yi-Fan Han
A comparative study of higher alcohols synthesis directly from syngas has been performed over monometallic Co and bimetallic CoCu/SiO 2 catalysts. Particularly, the role of Cu on the origin of active sites and reaction mechanism were investigated thoroughly using multiple techniques such as ex situ X-rays diffraction (XRD), X-ray absorption spectroscopy (XAS) and Raman spectroscopy. Reduction process of CoCu/SiO 2 catalysts was also determined using in situ XRD and in situ Raman spectroscopy while the surface structure of reduced catalysts was detected by CO-DRIFTS. CoCu bimetallic particles covered by Cu atoms are responsible for alcohols synthesis. The intrinsic kinetics was performed over both catalysts under realistic reaction conditions. By comparing the kinetic parameters, including apparent activation energies and reaction orders, the promotional effects of Cu have been identified as: (1) weakening the CO/HCO dissociation and reducing the formation of CH x species; (2) controlling surface Co ensemble size and inhibiting CH x insertion.
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RSC Advances
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2016
·Vol. 6
·期 13
·10365-10371
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IF 3.289
Lei Peng,Wenkang Lei,Ping Yu,Yunbai Luo
The separation of water and oil is a promising work due to the increasing worldwide oil pollution and leakage of chemical solvents. Superhydrophobic porous materials were prepared for their separation. In this work, various porous substrates of copper meshes, filter papers and polyurethane (PU) sponges were chosen to obtain superhydrophobic surfaces. Superhydrophobic surfaces were fabricated by polyvinylidene fluoride (PVDF) and hydrophobic nano-silica particle coatings through a spraying approach. The superhydrophobicity, stability of coatings and oil/water separation effect of these as-coated materials were studied. The results demonstrated that all the surfaces showed high water contact angles (>150°), good reusability and excellent oil selectively. Moreover, the coated filter paper was scaled up for practical use of removing trace water from mineral insulating oil in our group. It is promising that this superhydrophobic coating could be used in more applications.
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