SBS-OH模板制备CdS纳米粒子及表征

以SBS为基本原料,通过大分子化学反应制备得到羟基化SBS(SBS-OH).以N,N-二甲基甲酰胺为溶剂,SBS-OH为模板,乙酸镉及硫化钠为前驱物,在常温条件下"原位反应"制备得到CdS纳米粒子.通过UV-Vis、PL系统考察了SBS-OH浓度、前驱物浓度及配比等因素对CdS纳米粒子光学性质的影响.通过TEM对CdS纳米粒子的尺寸及形貌进行了表征.研究表明,利用SBS-OH的两亲性质,可以在极性溶剂DMF中得到具有冠状复合结构的CdS纳米粒子.随着前驱物浓度的增加,CdS纳米粒子的吸收强度增加,吸收带边红移,表现出较明显的量子尺寸效应.PL光谱表明CdS纳米粒子可以产生表面缺陷态的荧光发光特性,通过对实验结果的总结分析,探讨了复合结构CdS纳米粒子可能的形成机制.     

嵌段聚合物模板合成CdSe纳米粒子及表征

以羟基化SBS(SBS-OH)为模板,N,N-二甲基甲酰胺(DMF)为溶剂,硒代硫酸钠及乙酸镉为前驱物,"原位反应"制备了CdSe纳米粒子.通过紫外-可见吸收光谱、荧光光谱(PL)和透射电子显微镜(TEM)等方法对CdSe纳米粒子的光学性质及形貌进行了表征.结果表明,利用SBS-0H的两亲性质,可以在DMF中得到具有明...     

胺基端基树状分子在铜纳米粒子形成过程中的模板及稳定化作用

通过Micheal加成和胺解的交替反应,制得末端基为氨基的聚酰胺-胺型树状分子（PAMAM）;研究了第7代PAMAM（G7-NH2）在制备铜纳米粒子过程中的模板作用,通过紫外光谱和透射电镜表征了铜粒子的形成过程以及所得铜粒子的大小。结果表明,铜离子不仅与G7-NH2内部叔胺基形成络合物,还与树状分子外部的伯胺基形成络合物;在得到铜粒子的过程中,G7-NH2具有内模板和外模板作用,铜纳米粒子的尺寸随着铜离子与G7-NH2浓度比例的提高而增大;同时,由于铜纳米粒子为G7-NH2模板所包裹,使其在水中具有良好的分散均匀性和稳定性。但在有氧条件下,铜粒子很容易被氧化为G7-NH2（Cu^2＋）n络合离子。     

原位聚合法制备聚丙烯酸修饰的ZnS量子点

采用原位聚合法对ZnS量子点表面进行聚丙烯酸(PAA)的修饰。利用XRD、FTIR、TEM、TGA、荧光测试等对ZnS@PAA复合纳米粒子进行系列表征。XRD分析表明,修饰后的ZnS仍为立方晶相。FTIR和TGA结果证明,ZnS纳米粒子表面存在PAA。TEM结果表明,修饰后ZnS@PAA复合纳米粒子在去离子水中分散良好,其直径有所增加,约为28 nm,且呈较明显的核-壳结构。荧光测试发现,修饰PAA前后ZnS@PAA复合纳米粒子的发光特性没有发生明显改变。实验表明,经PAA修饰后,ZnS@PAA复合纳米粒子在水溶液中的分散性和稳定性得到提高,抗氧化性和荧光稳定性也得到了一定的增强。      

ZnS包覆 SiO2核壳和空腔结构纳米球制备研究

ZnS包覆SiO2三维核壳结构或空腔结构纳米球可用于光子晶体的组装.本实验采用层层自组装法,利用二氧化硅模板表面的静电作用吸附纳米晶粒子,生成纳米晶包覆层,制备核壳结构的SiO2@ZnS和SiO2@ZnS：Mn^2＋纳米球.控制氢氟酸对二氧化硅的蚀刻程度,制备了空腔型硫化锌纳米球.采用XRD、UV、PL、TEM、SEM、AFM等测试手段对核壳结构和空腔型硫化锌纳米球进行了表征.结果表明ZnS纳米晶包覆SiO2后,在其表面形成了包裹紧密、形貌规整、粒径均一的ZnS壳层;经5%氢氟酸蚀刻得到的空腔纳米球结构完好、厚度均匀.     

ZnS/PVA纳米复合薄膜的制备与表征

采用提拉真空干燥的方法制备出以石英玻璃为基板的ZnS/PVA纳米复合薄膜.ZnS/PVA纳米复合溶胶是通过直接混合法将ZnS纳米粒子与聚乙烯醇(PVA)高分子材料水溶液直接混合制备得到.ZnS纳米粒子由微乳液法制备得到.利用透射电子显微镜(TEM)和X射线衍射(XRD)分析表征了ZnS纳米粒子的微观形貌和晶型,TEM结果表明C12H25SH与Zn2 的比例越大,ZnS粒子的粒径越小且在PVA中的分散越好,当C12H25SH/Zn2 的比例为8∶1时,ZnS纳米粒子的粒径为50 nm,呈球状;XRD分析表明,PVA中ZnS纳米粒子具有类似于立方β-ZnS晶相.用紫外-可见(UV-VIS)吸收光谱和荧光光谱(PL)对其光学性能进行了表征,结果表明随着C12H25SH/Zn2 的摩尔比从4:1增长到8:1,ZnS/PVA纳米复合薄膜的吸收峰的强度逐渐增强,峰位也逐渐向短波长方向偏移.在280 nm下激发,PL中出现了峰位位于365 nm处的荧光发射峰;并且发现随着C12H25SH/Zn2 摩尔比从2:1增大到8:1,在C12H25SH/Zn2 摩尔比为4:1时,荧光发射峰的强度相对较大, 其余的荧光发射峰蓝移并且强度增大,表现出较为明显的量子尺寸效应;当C12H25SH/Zn2 摩尔比较大时,出现了低能发光(450 nm～467 nm)的现象.     

核壳结构CdS：Mn/ZnS纳米晶的制备与光学性能研究

以3-巯基丙酸为稳定剂,采用共沉淀法在水相中合成了CdS∶Mn掺杂纳米晶,然后进一步将ZnS包覆于CdS∶Mn纳米晶表面,制备了CdS∶Mn/ZnS核壳结构纳米晶。利用X射线衍射（XRD）,透射电子显微镜（TEM）和紫外-可见吸收光谱（UV-Vis）对纳米晶的结构、形貌和光学性质进行了表征,发现制备的纳米晶具有优秀的单分散性,确认合成了CdS∶Mn/ZnS核壳结构纳米晶。通过荧光光谱（PL）研究了纳米晶的发光性质和光稳定性,结果表明包覆壳层后纳米晶的发光强度显著提高,最高可达8倍,且Mn2＋离子的发光峰峰位置随着ZnS壳层数的增加而红移。此外,核壳纳米晶的光稳定性大大提高。     

核壳结构CdS/ZnS荧光量子点的制备与荧光性能研究

以氧化镉为镉源、硫单质为硫源、油酸为配体、在十八烯体系中合成单分散的CdS纳米颗粒,研究了配体浓度对纳米微粒的生长动力学、颗粒尺寸分布的影响.采用乙基黄原酸锌作为Zn、S源的反应前体,采用逐滴滴加的方法制备了具有核壳结构的CdS/ZnS量子点,吸收光谱和荧光光谱表明CdS/ZnS纳米粒子比单一的CdS纳米粒子具有更优异的发光特性.透射电子显微镜、X射线粉末衍射、X射线光电子能谱、选区电子衍射证明ZnS在CdS表面进行了有效包覆.所制备核壳结构纳米粒子具有较好的尺寸分布,荧光发射峰半高峰宽为18～20nm,荧光量子产率达40%.     

不同壳层的CdS／ZnS核／壳结构量子点的温度相关荧光性质

报导了CdS／ZnS纳米晶体（NCs）的制备过程和其光学}生质。通过采用连续离子层吸附和反应技术（SILAR）,我们用少量的表面活性剂合成了不同壳层的四个样品,包括CdS核纳米晶以及具有1～3层ZnS壳的CdS／ZnS核／壳结构纳米晶体样品。发现具有一层ZnS壳的CdS／ZnS样品的荧光量子产率大约比未包覆壳层的CdS纳米晶体样品的强11倍。另外,随着壳层的增加（增至两到三层）,荧光量子产率呈现下降的趋势。对样品进行了温度相关的光谱测量,发现CdS／ZnS和CdS一样具有特殊的光学特性。     

水溶液中组装碳纳米管/硫化锌纳米晶复合膜

半导体材料ZnS在光催化领域具有重要的应用前景，如何提高其光催化能力仍是目前关键问题之一。应用碳纳米管的独特结构和性能有望调变和改善ZnS的催化功能。采用一种简便的方法在水溶液中成功组装了硫化锌／碳纳米管纳米晶颗粒（ZnS／CNTs）复合膜。TEM显示纳米复合膜以CNTs组装成席状骨架，ZnS纳米晶填充在CNTs间的缝隙或者包裹在CNTs的表面，二者之间存在良好的接触和相互作用。生成的ZnS纳米颗粒尺寸均匀、大小约为5nm。用EDS、SAED和XRD分析了复合膜的元素组成以及ZnS的晶相结构。结果显示ZnS纳米晶为闪锌矿结构。     

羟基化SBS模板合成金纳米粒子及表征

以羟基化SBS为模板,N,N-二甲基甲酰胺(DMF)为溶剂,氯金酸为原料,硼氢化钠为还原剂,在一定反应条件下制备得到了金纳米粒子。采用紫外-可见光谱和透射电子显微镜等方法对所合成的纳米金样品进行了表征。结果表明,羟基化SBS可以为金纳米粒子的成核和长大起到较好的模板作用,金纳米粒子可以产生纳米金所具有的表面等离子态的特征吸收峰;改变合成条件,可以控制金纳米粒子特征吸收峰的位置;透射电子显微镜给出金纳米粒子具有球状形貌特征,且具有较窄尺寸分布。     

A facile synthesis of ZnS nanocrystallites by pyrolysis of single molecule precursors,Zn (cinnamtscz)<Subscript>2</Subscript> and ZnCl<Subscript>2</Subscript> (cinnamtsczH)<Subscript>2</Subscript>

ZnS nanocrystallites were synthesised by pyrolysis method using Zn (cinnamtscz)₂ and ZnCl₂ (cinnamtsczH)₂ (cinnamtsczH = cinnamaldehyde thiosemicarbazone) as single source precursors. The prepared ZnS nanocrystallites were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction, UV-Vis and fluorescence spectroscopy. The peak broadening in XRD and emission at shorter wavelength in fluorescence spectra showed the presence of nanocrystallites. The blue shift in UV-Vis absorption spectroscopy also proved the formation of nanocrystallites. TEM images show presence of plate-like and spherical ZnS nanoparticles obtained from Zn(cinnamtscz)₂ and ZnCl₂ (cinnamtsczH)₂ respectively.     

Fe：ZnSe/ZnS核-壳纳米晶的微乳液法合成及光学性能研究

在环己烷/Triton X-100/水/异丙醇W/O型微乳液体系中制备了Fe：ZnSe/ZnS核-壳纳米晶。采用X射线衍射仪（XRD）分析了产物的结构,利用透射电子显微镜（TEM）观察了产物的形貌,采用光致发光（PL）谱、紫外-可见（UV-Vis）吸收谱测试了产物的光学性能。着重研究了水与表面活性剂的摩尔比（R值）对合成产物的光学性能的影响。并对相关现象潜在的机理进行了讨论。     

Synthesis and photoluminescence properties of Cl-doped ZnS nanoparticles prepared by a solid-state reaction

ZnS:Cl⁻ nanoparticles with strong blue emission have been synthesized successfully by a solid-state reaction at low temperature. The dependence of photoluminescence (PL) properties of ZnS:Cl⁻ nanoparticles on the Cl⁻ contents was researched, and the influences of the annealing ambience and using polyvinyl alcohol (PVA) during the synthesis on the PL of ZnS:Cl⁻ (Cl/Zn = 0.35) nanoparticles were discussed. X-ray power diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and ultraviolet-visible spectroscopy were used to characterize their structure, chemical state, diameter, surface states, and PL properties. The results showed that ZnS:Cl⁻ nanoparticles had a cubic blende crystal structure and an average crystallite size of 17.40–19.16 nm. The most intensity blue emission peaking at about 425 nm was obtained when Cl/Zn = 0.35 under 330 nm excitation at room temperature. The emission intensity of ZnS:Cl⁻ (Cl/Zn = 0.35) was increased 3-fold than that of ZnS. The results showed that the PL of ZnS:Cl⁻ (Cl/Zn = 0.35) nanoparticles was enhanced after annealing or using PVA during the synthesis, and annealing in vacuum had a stronger effect in improving the luminescence properties of ZnS nanoparticles than in air. This work suggests that it is an effective method to improve the PL intensity of ZnS nanocrystals by doping with Cl⁻ in ZnS.     

Phase and morphology controlled synthesis of high-quality ZnS nanocrystals

Through a facile solvothermal method, the controlled preparation of ZnS nanocrystals with different phases and morphologies was achieved only by changing the organic additives. By adding the surfactant of sodium dodecyl benzene sulfonate (SDBS) into the reaction, the cubic heart-like ZnS nanoparticles with uniform size were obtained in a large scale. While, with the assistance of the biomolecule of alginic acid, the pure phase of hexagonal ZnS nanospheres assembled from small ZnS nanoparticles were synthesized. The optical properties of the obtained ZnS nanocrystals were investigated by ultraviolet-visible (UV-vis) absorption and photoluminescence (PL) spectra. The quantum confinement effect could be observed clearly in ZnS nanoparticles.     

低温水热法制备ZnS:Co+Cr纳米晶及其光学性能研究

采用低温水热法制备出3-巯基丙酸(MPA)修饰的ZnS:Co+Cr纳米晶. 利用X射线衍射仪、粒度分析仪、透射电镜、紫外-可见分光光度计、荧光分光光度计和XPS能谱仪等对ZnS:Co+Cr纳米晶的结构、形貌、粒径分布和发光性能进行了表征. 结果表明: 合成的ZnS:Co+Cr纳米晶有较好的单分散性, 平均粒径为9.3 nm, 均为立方闪锌矿结构; ZnS:Co+Cr纳米晶的吸收边位于320 nm处, 并在728 nm处出现Co²⁺的特征吸收峰; 当Cr²⁺浓度为0.75at%, 水热反应温度为160℃时, ZnS:Co+Cr纳米晶PL峰最强; XPS能谱表明Cr²⁺部分被氧化成Cr³⁺。     

Synthesis and study of photoluminescence characteristics of carbon nanotube/ZnS hybrid nanostructures

Single-walled carbon nanotube (SWCNT) samples were rigorously purified by high temperature oxidation, acid treatment, ultrasonication, neutralisation and filtration process. By a very simple wet chemical route, SWCNT bundles were hybridised with freshly prepared ZnS nanocrystals of average size 2.00 nm. Characterisation of the prepared samples was done by scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution transmission electron microscopy, Fourier transform infrared ray spectroscopy, Raman spectroscopy and UV-Vis spectroscopy. Photoluminescence (PL) study of the SWCNT/ZnS hybrid structure showed two distinct types of emission patterns depending upon the excitation wavelength, one in the ultraviolet region wavelengths and the other, for the higher excitation wavelength range, when the PL spectrum mostly covered the visible region.     

Low-temperature synthesis of hexamethylenetetramine-stabilised ZnS nanoparticles and its photocatalytic properties

ZnS nanoparticles have been synthesised at low temperature by short reaction (80°C for 2?h) via wet chemical route. The nanoparticles were stabilised using hexamethylenetetramine (HMTA) as surfactant in aqueous solution. The average particle size calculated from X-ray diffraction studies was about 4?nm with cubic zincblende structure. The presence of HMTA in the synthesised ZnS nanoparticles was confirmed by FTIR studies. A significant blue shift was observed in the optical absorption band edge for the ZnS nanoparticles as compared to the bulk, indicating a strong quantum confinement. The room temperature photoluminescence (PL) spectrum showed a broad green emission peak at around 502?nm. The photocatalytic property of HMTA-stabilised ZnS nanoparticles were investigated on the decolourisation of methylene blue aqueous solution under UV light irradiation.     

ZnS:Mn荧光粉的溶剂热法制备及其发光性能

采用溶剂热法合成了ZnS∶Mn荧光粉,讨论了锰掺杂量对硫化锌发光性能的影响。通过扫描电镜(SEM)、X射线粉末衍射仪(XRD)、紫外可见分光光度计(UV-Vis)和荧光分光光度计(PL)对合成的ZnS∶Mn荧光粉的结构和光学性能进行了表征。结果表明:ZnS∶Mn荧光粉的平均粒径为13.5nm,在波长340nm~200nm处有强吸收,Mn离子浓度在所研究范围内,锰掺杂量对硫化锌的晶型、结晶度、粒径无影响,但对其能级结构影响显著,且随着Mn离子掺杂量的增加,发光强度先增加后减小,掺杂量为5%时达到最大值。