共查询到18条相似文献,搜索用时 109 毫秒
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以醋酸铅为铅源,硫代乙酰胺为硫源,在表面活性剂十二烷基硫酸钠(SDS)和十六烷基三甲基溴化铵(CTAB)共同作用下,通过简单地调节水热反应的反应温度控制合成出球状、立方状和空心立方状PbS纳米晶。利用XRD、TEM对合成产物的结构和形貌进行了表征,发现合成的球状、立方状和空心立方状PbS纳米晶尺寸均一,直径为100 nm左右。对球状、立方状和空心立方状PbS纳米晶的形成机理进行了初探,结果表明反应温度较低时,水热反应初始阶段形成的PbS小颗粒呈球形,在表面活性剂SDS的烷基链模板和CTAB微胶束软模板共同作用下生成球状PbS纳米晶;反应温度较高时,水热反应初始阶段形成的PbS小颗粒由于自身的立方相岩盐晶体结构的影响有呈立方状趋势,在SDS和CTAB共同作用下产物堆积成空心立方体状或立方状。 相似文献
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用聚乙二醇辛基苯基醚(OP)/异辛醇/环己烷/水溶液所形成的微乳液体系控制合成出了PbS纳米粒子,考察了微乳液中水与表面活性剂的物质的量的比(ω0)、反应物浓度及浓度比、陈化时间等条件对产物形貌的影响。采用透射电子显微镜(TEM)、X-射线衍射(XRD)分别对产物的结构、粒度和形貌进行了表征。结果表明,在微乳液体系中,控制不同的实验条件,可以成功地合成球形、梭形、针状和棒状的PbS纳米粒子,并且粒径分布集中,无团聚现象。论文还对不同形貌PbS纳米粒子的形成机理进行了探讨。 相似文献
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发现了PbS纳米微粒对溴化银乳剂的化学增感作用,对PbS和Na2S2O3对卤化银乳剂的增感作用进行了比较,研究了增感剂用量、增感温度和pAg值、溴化银的晶型等因素的影响,以及PbS纳米微粒与HAuCl4的协同增感效应. 相似文献
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以无机硫为原料制备硫化铅量子点及其表征 总被引:1,自引:0,他引:1
根据高温下快速成核低温下慢速生长的量子点制备原理, 采用胶体化学的方法成功制备了不同粒径的硫化铅半导体量子点. 这种方法的特点是以无味和低毒的硫化钠作为制备硫化铅量子点硫的前驱物, 因此这是一种量子点的绿色化学合成方法. 油酸作为稳定剂控制硫化铅的粒径. 采用X射线衍射和高分辨透射电镜表征了量子点的晶体结构、形貌和粒径, 采用可见-近红外吸收光谱研究了硫化铅量子点的量子尺寸效应. 通过降低油酸的添加量可以促进量子点的生长, 得到较大粒径量子点. 并探讨了量子点的生长机理. 相似文献
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Shipra Mital Gupta 《High Energy Chemistry》2013,47(3):130-134
Nanoparticles of lead sulphide have been stabilized in the presence of excess Pb2+ in aqueous basic medium by a simple chemical route of synthesis. These PbS nanoparticles were synthesized very conveniently at room temperature using hexametaphosphate as stabilizer. These nanoparticles have an absorption extending into the NIR region. A significant quantum confinement effect made the bandgap of lead sulphide nanoparticles produce a blue shift from 0.41 eV to about 1.5 eV. The size and morphology of the particles were studied by TEM. Particles were relatively small sized (about 6 nm) having narrow size distribution. XRD data analysis indicate that the product is a mixture of PbS, PbO and Pb(OH)2. Both XRD pattern and HRTEM images confirm the crystalline structure of lead sulphide crystals. IR spectroscopy indicates the formation of PbS. PbS nanoparticles were fairly stable and could be stored for about three weeks at room temperature and for about two months at 5°C without agglomeration. These particles were photoactive and sensitized the reaction of aniline by light leading to the formation of azobenzene. 相似文献
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A kind of blue phase liquid crystal (BPLC), consisting of nematic liquid crystal, E7, and chiral dopants, CB15 and R1011, was investigated by doping PbS nanoparticles. The blue phase temperature range was extended from 3oC to 4.6°C by doping PbS nanoparticles with diameters around 9.6 nm. A kind of porous texture was observed both in the forming process of PbS nanoparticles doped BPLCs as well as in the BPLCs (with/without PbS nanoparticles) under assisting electric field. The porous texture may indicate that the liquid crystals molecule should be reoriented during the formation process of PbS nanoparticles doped BPLCs. 相似文献
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AbstractLead(II) methyl xanthate [Pb(S2COMe)2] was synthesized and characterized by single crystal X-ray crystallography. The molecular structure showed a distorted tetrahedral geometry around Pb(II) with each monomeric unit linked with another through Pb···S interactions. The compound was used to prepare hexadecylamine capped PbS (HDA-PbS) and oleylamine capped PbS (OLA-PbS) nanoparticles. The PbS nanoparticles were indexed to the cubic PbS crystalline phase with particle sizes of 4.5 – 34.5?nm. The estimated optical bandgaps obtained from the tauc’s plots were 3.47 and 3.30?eV for HDA-PbS and OLA-PbS, respectively, which are blue shifted in comparison to bulk PbS. The photodegradation of methylene blue using PbS as photocatalyst shows that HDA-PbS have the best degradation efficiency of 77.70% after 240?min. 相似文献
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A. L. Stroyuk A. E. Raevskaya S. Ya. Kuchmii 《Theoretical and Experimental Chemistry》2006,42(6):346-351
It was established that PbS nanoparticles significantly increase the rate of formation of lead selenide during the reaction
of Pb(NO3)2 and Na2SeSO3 in aqueous solutions of polymers. It was shown that the reaction product consists of PbS/PbSe nanoparticles with a “PbS core-PbSe
shell” structure. A correlation was found between the forbidden band widths of the PbS nanoparticles and the PbS/PbSe nanostructures
formed during the reaction.
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Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 42, No. 6, pp. 339–344, November–December, 2006. 相似文献
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T. Saraidarov R. Reisfeld A. Sashchiuk E. Lifshitz 《Journal of Sol-Gel Science and Technology》2003,26(1-3):533-540
PbS nanocrystals (NCs) ranging between 4–8 nm were incorporated into Zirconium-Silica-Urethane (ZSUR) matrix obtained by the sol-gel method. The sizes of the particles were controlled by temperature treatment and by concentration of PbS in ZSUR matrix. The sizes of PbS NCs were determined by TEM measurements. The quantum size effect could also be extracted from optical absorption and photoluminescence spectra. The new matrix allows incorporation of up to 40% PbS forming a characteristic structure of dendrite by reacting lead acetate with ammonium thiocyanate in sol-gel matrix. The sol precursors of the matrix for Zirconium-Silica-Urethane contained zirconium oxide (ZrO2) matrix solution, tetramethoxysilane (TMOS), 3-glycid oxypropyl trimethoxysilane (GLYMO) and polyethylene urethane silane (PEUS) synthesized separately. The ZrO2 matrix solution was obtained from zirconium n-tetrapropoxide in propanol and acetic acid was used as a chelating agent to stabilize the zirconium oxide precursor. 相似文献
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Mohammad Yousefi Mohammad Sabet Masoud Salavati-Niasari Hamid Emadi 《Journal of Cluster Science》2012,23(2):511-525
PbS and Bi2S3 nanostructures were synthesized successfully via a microwave approach. For synthesis of PbS nanoparticles, a new precursor, [bis(salisylate) lead (ΙΙ)]; [Pb(Hsal)2] was used. The products were characterized by X-ray diffraction, scanning electron microscopy, and photoluminescence spectroscopy. Thin film of Bi2S3 was prepared by doctor’s blade technique and solar cell made from ITO/Bi2S3/PbS/Pt layers. I–V characterization was investigated for this cell and fill factor, open circuit voltage and short circuit current values were obtained. 相似文献
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RNA-mediated fluorescent Q-PbS nanoparticles 总被引:1,自引:0,他引:1
RNA-mediated fluorescent PbS nanoparticles have been synthesized in the quantum-confined region of a face-centered cubic phase. The binding of RNA to the surface of PbS nanoparticles has been exploited to tailor its size and to improve the stability and electronic properties. These particles display excitonic features and a relatively strong narrow emission band (fwhm 70 nm) at 675 nm with a broad excitation range extending from 330 to 620 nm. The manipulation of experimental conditions could control the relaxation dynamics of charge carriers in the illuminated particles. The multifunctionality of the RNA structure contributes to the observed electronic properties in a cooperative manner. Such biopolymeric nanostructures may find tremendous applications in the fabrication of solar cells, fluorescence imaging, and detection devices. 相似文献