共查询到18条相似文献,搜索用时 62 毫秒
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表面活性剂存在下氢化物发生原子荧光法测定微量硒的研究及应用 总被引:6,自引:0,他引:6
研究了不同表面活性剂对硒的氢化物发生原子荧光测定(HG-AFS)的影响,发展了一种灵敏度高、选择性好的HG-AFS测定硒的方法。在定量还原Se(Ⅳ)为Se(Ⅳ)的条件下,测定了补硒品康必硒中的Se(Ⅳ)、Se(Ⅳ)和有机硒的含量。 相似文献
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在现代纳米科学技术领域中,铜纳米线由于具有独特的光学、电学、力学和热学性质而成为制备透明柔性导电电极的优良材料。铜价格低廉,自然存储量较大,是实际应用中替代贵金属的理想材料。然而,将铜离子还原为单质铜比较困难,且单质铜非常容易被氧化,这成为应用中亟需解决的关键问题。如何制备单分散、稳定且具有抗氧化性的铜纳米线也成为该领域的研究热点。在各种制备铜纳米线的方法中,液相还原法不仅可以解决以上问题,且该方法具有制备条件限制少、成本低、简单易行等优点而被广泛应用于铜纳米线的大量合成。本文从铜纳米线的研究背景和研究价值入手,首先综述了不同(光滑或粗糙、单晶或孪晶)铜纳米线的液相制备方法及其生长机制。讨论了铜纳米线的氧化及其抗氧化表面包覆问题。最后对铜纳米线的研究意义和应用前景做出展望。 相似文献
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0IntroductionSelenium(Se)iswellknownforitsphotoelectri鄄calandsemiconductorpropertiesandhasbeensuc鄄cessfullyusedinsolarcells,rectifiers,photographicexposuremetersandxerography[1].Itcouldbeexpect鄄edthattheuniquestructureandthequalityofone鄄di鄄mensional( 相似文献
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对两类新型表面活性剂--Bola型表面活性剂和Gemini型表面活性剂,从结构特点、研究历史、水中的溶解性与Krafft点、表面活性与表面吸附、临界胶团浓度、水中的聚集体类型与转化、研究前景等方面进行综述. 相似文献
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聚乙烯醇系高分子表面活性剂 总被引:2,自引:0,他引:2
聚乙烯醇(PVA)系高分子表面活性剂,可用作乙烯基单体乳液均聚或共聚的乳化剂和氯乙烯(VC)悬浮聚合的分散稳定剂。本文主要介绍它的分类、性能、应用和乳化分散作用机理。 相似文献
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《Macromolecular rapid communications》2017,38(12)
Novel structures comprised of GaAs nanowire arrays conformally coated with conducting polymers (poly(3,4‐ethylenedioxythiophene) (PEDOT) or poly(3,4‐ethylenedioxythiophene‐co‐3‐thiophene acetic acid) display both sensitivity and selectivity to a variety of volatile organic chemicals. A key feature is room temperature operation, so that neither a heater nor the power it would consume, is required. It is a distinct difference from traditional metal oxide sensors, which typically require elevated operational temperature. The GaAs nanowires are prepared directly via self‐seeded metal–organic chemical deposition, and conducting polymers are deposited on GaAs nanowires using oxidative chemical vapor deposition (oCVD). The range of thickness for the oCVD layer is between 100 and 200 nm, which is controlled by changing the deposition time. X‐ray diffraction analysis indicates an edge‐on alignment of the crystalline structure of the PEDOT coating layer on GaAs nanowires. In addition, the positive correlation between the improvement of sensitivity and the increasing nanowire density is demonstrated. Furthermore, the effect of different oCVD coating materials is studied. The sensing mechanism is also discussed with studies considering both nanowire density and polymer types. Overall, the novel structure exhibits good sensitivity and selectivity in gas sensing, and provides a promising platform for future sensor design.
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Christopher Schneider Dr. Ning Liu Dr. Stefan Romeis Prof. Dr. Wolfgang Peukert Prof. Dr. Patrik Schmuki 《ChemistryOpen》2019,8(7):817-821
Anatase nanowires were synthesized in solution by using a simple mixing of titanium diisopropoxide bis(acetylacetonate), lactic acid and sodium hydroxide at room temperature. We discuss effects of reaction parameters and post treatment (annealing) on the nanowire morphology, surface area, and crystallinity, as well as the competing morphology directing effects of lactic acid and sodium hydroxide. Then the room temperature nanowires were directly grown onto fluoride doped tin oxide (FTO) glass to form photoanodes. Photoelectrochemical measurements of the different nanowires were performed and compared to conventional nanowires produced by high temperature synthesis. Clearly the nanowires introduced in this work show a significant increase in the maximum photocurrent, compared to classic hydrothermal nanowire layers. 相似文献
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抗坏血酸为还原剂制备Se纳米线(英) 总被引:2,自引:0,他引:2
0IntroductionOne鄄dimensionalnanostructuressuchasnanowires,nanorods,ornanotubeshavebeenthesub鄄jectofintensiveresearchduetotheirpotentialuseasactivecomponentsorinterconnectsinfabricatingnanoscaleelectronicorelectromechanicaldevices[1].Theyalsorepresentane… 相似文献
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Self‐Template‐Directed Synthesis of Porous Perovskite Nanowires at Room Temperature for High‐Performance Visible‐Light Photodetectors 下载免费PDF全文
Sifei Zhuo Jingfang Zhang Yanmei Shi Yi Huang Prof. Dr. Bin Zhang 《Angewandte Chemie (International ed. in English)》2015,54(19):5693-5696
The unique optoelectronic properties and promising photovoltaic applications of organolead halide perovskites have driven the exploration of facile strategies to synthesize organometal halide perovskites and corresponding hybrid materials and devices. Currently, the preparation of CH3NH3PbBr3 perovskite nanowires, especially those with porous features, is still a great challenge. An efficient self‐template‐directed synthesis of high‐quality porous CH3NH3PbBr3 perovskite nanowires in solution at room temperature using the Pb‐containing precursor nanowires as both the sacrificial template and the Pb2+ source in the presence of CH3NH3Br and HBr is now presented. The initial formation of CH3NH3PbBr3 perovskite layers on the surface of the precursor nanowires and the following dissolution of the organic component of the latter led to the formation of mesopores and the preservation of the 1D morphology. Furthermore, the perovskite nanowires are potential materials for visible‐light photodetectors with high sensitivity and stability. 相似文献
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Ming-Shu Chiu Chun-Chieh Lin An-Ting Lee Yi-Chuan Huang Prof. Michael H. Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(1):367-372
A simple aqueous-phase synthesis of PbSe nanocubes with tunable sizes has been developed by first preparing a Na2SeSO3 stock solution through dissolution of selenium powder in a solution of Na2SO3 at 90–100 °C for 30 min, and adding part of this solution to a mixture of lead acetate and acetic acid at room temperature with stirring for only 5–8 min to complete the nanocrystal growth. Adjusting the volume of acetic acid and Na2SeSO3 solution added enabled the size of the nanocrystals to be tuned, with average edge lengths of 13 to 121 nm attained. Changes in solution color revealed very different crystal growth rates for the 13 and 121 nm nanocubes. The PbSe cubes exhibit size-dependent absorption bands in the ultraviolet and visible-light region; the band positions show progressive redshifts with increasing particle size. Slight photocatalytic activity upon 532 nm laser irradiation of the nanocubes suggests the presence of higher energy levels in the band structure of PbSe. The synthetic conditions can be easily scaled up to obtain a large quantity of PbSe nanocubes for applications. 相似文献