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41.
借助原位液体透射电镜,我们观察并研究了钯纳米棒溶液环境下的氧化刻蚀的微观行为及机理。通过改变钯纳米棒所处的液体环境,有效地控制了钯纳米棒的氧化刻蚀行为。由于端部具有较高的反应活性,钯纳米棒在氯化铁溶液中的氧化刻蚀会选择沿着轴向进行,具有明显的各向异性。当反应在超薄液层进行时,钯纳米棒的氧化刻蚀会变为准各向同性。这种行为是由于超薄溶液中溶解产物以及氧化物的扩散被抑制,在纳米棒端部选择性发生的氧化刻蚀会受到阻碍。最后,我们发现在钯纳米棒端部选择性沉积金,可以保护纳米棒的端部不受氧化,从而能控制刻蚀沿着钯纳米棒的径向进行。本文的研究结果对贵金属纳米晶的结构参数的精确调控以利于实际应用具有重要的意义。 相似文献
42.
Highly Effective Detection of Amitraz in Honey by Using Surface-Enhanced Raman Scattering Spectroscopy Coupled with Chemometric Methods
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Xin-ming Nie Jing Wang Xun Wang Ya-ping Tian Si Chen Zhou-yang Long Cheng-hua Zong 《化学物理学报(中文版)》2019,32(4):444-450
As an effective and universal acaricide, amitraz is widely used on beehives against varroasis caused by the mite Varroa jacobsoni. Its residues in honey pose a great danger to human health. In this study, a sensitive, rapid, and environmentally friendly surface-enhanced Raman spectroscopy method (SERS) was developed for the determination of trace amount of amitraz in honey with the use of silver nanorod (AgNR) array substrate. The AgNR array substrate fabricated by an oblique angle deposition technique exhibited an excellent SERS activity with an enhancement factor of ∽107. Density function theory was employed to assign the characteristic peak of amitraz. The detection of amitraz was further explored and amitraz in honey at concentrations as low as 0.08 mg/kg can be identified. Specifically, partial least square regression analysis was employed to correlate the SERS spectra in full-wavelength with Camitraz to afford a multiple-quantitative amitraz predicting model. Preliminary results show that the predicted concentrations of amitraz in honey samples are in good agreement with their real concentrations. Compared with the conventional univariate quantitative model based on single peak’s intensity, the proposed multiple-quantitative predicting model integrates all the characteristic peaks of amitraz, thus offering an improved detecting accuracy and anti-interference ability. 相似文献
43.
O. Lupan L. Chow G. Chai A. Schulte S. Park O. Lopatiuk-Tirpak L. Chernyak H. Heinrich 《Superlattices and Microstructures》2008
We have investigated three-dimensional (3-D) architectures–microspheres and radial structures–based on biopolymer-assisted self-assembly from one-dimensional ZnO nanorods. The developed method is simple, rapid and cost-effective and can be used for self-assembly of different complex superstructures. A possible model of 3-D architectures self-assembled with biopolymer assistance is presented using minimum energy considerations. Scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, micro–Raman spectroscopy and cathode luminescence investigations show that the novel 3-D architectures are built from high-purity ZnO nanorods with a wurtzite structure. The resulting radial structures show an intense ultraviolet (UV) cathode luminescence emission suggesting applications as UV light emitting diodes or lasers. Their structural characteristics endow them with a broad area of applications and offer a possibility to be used as fundamental low-dimensional building units. These building units open opportunities for the self-assembly of multifunctional nanostructured systems with applications in bioscience and nanomedicine, electronics and photonics. 相似文献
44.
Mi Ouyang Dacheng Dai Xuming Hu Yuwen Li Zhangxin Chen Bowen Tao Lina Zhang Weijun Li Yujie Dong Ru Bai Xiaojing Lv Cheng Zhang 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2269-2279
A new star-shaped structure conjugated microporous polymers, poly (2,8,14-tri[4-diphenyl-benzene]-hexaazatrinaphthylene) (PTPA-HATN), was designed and in-situ electrochemically polymerized on the surfaces of FTO electrodes with a directional alignment TiO2 nanorod array to obtain TiO2/PTPA-HATN core-shell nanocomposite films. Compared with the PTPA-HATN film, the TiO2/PTPA-HATN composite film exhibits higher optical contrast and faster response time, with contrast of 57% at 783 nm, coloring time of 3.62 s and discoloring time of 2.55 s (43%, 4.63 s and 4.77 s for PTPA-HATN film, respectively). After 400 cycles, the contrast of nanocomposite film decreased by 28%, while the PTPA-HATN film basically lost its electrochromic properties. A simple three-layer EC prototype device based on TiO2/PTPA-HATN nanocomposite film constructed with hydrogel electrolyte clearly shows color changes at different voltages. On the one hand, the formation of core-shell porous nanostructure of TiO2/PTPA-HATN composite film provides a larger ion doping/de-doping interface, shortening the average diffusion length of ions. On the other hand, the large indented polymer-nanorods contact interface makes it difficult for the polymer to detach from the electrode, thus significantly improving the cyclic stability of the composite film. 相似文献
45.
Obtaining superhydrophobic surfaces for their application in electronics and flexible wearable devices remains a significant challenge. Most previously reported methods for obtaining superhydrophobic surfaces involve complex and expensive preparation techniques and thus cannot be used for practical applications. Ion-beam irradiation is a simple and promising method for fabricating superhydrophobic nanostructures on large areas at a low cost. Ion-beam irradiation using argon and oxygen gases was used to prepare silica nanorod structures on glass substrates. This study is not just a modification of the surface of nanoparticles, but a change in nanoparticle shape. The nanorods were subsequently treated with perfluorooctyltriethoxysilane to obtain superhydrophobicity. The surface of the silica nanorods exhibited a static water contact angle of 153°, indicating superhydrophobicity. The combination of rough structures of silica nanorods and low surface energy resulted in superhydrophobicity. The surface properties were evaluated in detail using Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The proposed method is facile, inexpensive, and can be used for the large-scale production of nanorod structures for potential industrial applications. 相似文献
46.
Phase‐Transition Induced Conversion into a Photothermal Material: Quasi‐Metallic WO2.9 Nanorods for Solar Water Evaporation and Anticancer Photothermal Therapy
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Lei Sun Zhuo Li Rui Su Yuanlin Wang Zhenglin Li Baosheng Du Prof. Ye Sun Prof. Pengfei Guan Prof. Flemming Besenbacher Prof. Miao Yu 《Angewandte Chemie (International ed. in English)》2018,57(33):10666-10671
Phase transition from WO3 to sub‐stoichiometric WO2.9 by a facile method has varied the typical semiconductor to be quasi‐metallic with a narrowed band gap and a shifted Femi energy to the conduction band, while maintaining a high crystallinity. The resultant WO2.9 nanorods possess a high total absorption capacity (ca. 90.6 %) over the whole solar spectrum as well as significant photothermal conversion capability, affording a conversion efficiency as high as around 86.9 % and a water evaporation efficiency of about 81 % upon solar light irradiation. Meanwhile, the promising potential of the nanorods for anticancer photothermal therapy have been also demonstrated, with a high photothermal conversion efficiency (ca. 44.9 %) upon single wavelength near‐infrared irradiation and a high tumor inhibition rate (ca. 98.5 %). This study may have opened up a feasible route to produce high‐performance photothermal materials from well‐developed oxides. 相似文献
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