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1.
制备了苯甲酸钐/聚氨酯复合材料,并对其荧光性能进行了研究,获得了复合材料荧光强度与稀土质量分数间的依赖关系。结果表明,选择易于与稀土离子配位的有机基体与稀土有机配体进行熔体共混可显著提高二者相容性,可以获得稀土离子质量分数较高、分布较为均匀的稀土/高分子复合材料。  相似文献   

2.
《应用化工》2022,(9):2223-2228
由硝酸锌、硝酸钐、十二烷基硫酸钠制备Sm掺杂棒花状纳米氧化锌,考察制备温度、分散剂浓度、Sm掺杂等因素对氧化锌形貌和光催化性能的影响,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量色散X射线谱(EDS)、X射线光电子能谱(XPS)进行表征。结果表明,制备温度、分散剂浓度、Sm掺杂量等对棒花状纳米氧化锌的形貌和光催化性能有显著的影响。在60℃下,分散剂浓度为28 mmol/L、Sm掺杂量为5%时,所制备的棒花状纳米氧化锌的形貌规整且光催化性能最好。  相似文献   

3.
采用溶胶-凝胶法制备Sm掺杂TiO2催化剂,并用X射线衍射、TEM等技术表征了催化剂,考察了催化剂的煅烧温度、催化剂用量以及掺杂量对光催化降解甲基橙效率的影响。结果表明:催化剂煅烧温度为500℃,最佳用量为100mg/mL,钐的最佳掺杂量为Sm/Ti摩尔比1%。  相似文献   

4.
采用化学沉淀法制备Y/ZnO光催化剂,以光催化降解甲基橙为探针反应,考察Y掺杂的ZnO光催化活性,并采用X射线衍射、红外光谱和紫外漫反射等手段对其进行结构表征.结果表明,Y掺杂的ZnO光催化剂对甲基橙降解具有良好的活性.活性及催化剂结构表征结果表明,最佳Y掺杂质量分数为0.1%,以掺杂Y质量分数为0.1%的Y/ZnO为...  相似文献   

5.
由硝酸锌、硝酸钐、十二烷基硫酸钠制备Sm掺杂棒花状纳米氧化锌,考察制备温度、分散剂浓度、Sm掺杂等因素对氧化锌形貌和光催化性能的影响,采用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、能量色散X射线谱(EDS)、X射线光电子能谱(XPS)进行表征。结果表明,制备温度、分散剂浓度、Sm掺杂量等对棒花状纳米氧化锌的形貌和光催化性能有显著的影响。在60℃下,分散剂浓度为28 mmol/L、Sm掺杂量为5%时,所制备的棒花状纳米氧化锌的形貌规整且光催化性能最好。  相似文献   

6.
用磁控溅射成功制备出V掺杂ZnO压电薄膜。在不同温度对样品进行退火处理,采用扫描电子显微镜(SEM)、X射线衍射(XRD)和X射线光电子能谱仪(XPS)对薄膜的表面形貌、晶体结构和表面化学状态进行表征,并测量了不同退火温度下薄膜样品的电流密度(J)-电压(V)曲线。结果表明,高温退火后V向ZnO晶格内部迁移,引起晶格畸变,形成表面氧空位。随着退火温度的升高,非线性系数先增大后减小,薄膜的压敏电压逐渐增大,漏电流密度先减小后增大。800℃退火后样品表面氧空位浓度最高,薄膜具有较为理想的综合电性能,其非线性系数为15.19,压敏电压为5.13 V,漏电流密度为0.42μA·mm-2。  相似文献   

7.
单分散球形Sm掺杂的CeO2粉体的均相沉淀法制备   总被引:5,自引:1,他引:5  
由均相沉淀法制备了Sm掺杂的CeO2粉体(SDC), 即在硝酸盐溶液中加入过量的尿素, 加热使尿素分解释放OH-生成沉淀, 经过滤、洗涤、焙烧得到所需的粉体.通过控制反应条件可对粉体的形貌和粒径进行控制.在500 ℃焙烧的粉体是面心立方相, 随着焙烧温度的提高, 晶型不变, 晶粒尺寸增大.将600 ℃焙烧的粉体压片在1 500 ℃烧结, 其相对密度达到95%以上, 其电导率在800 ℃能达到0.07 S*cm-1.  相似文献   

8.
对白光发光二极管(light-emitting diode,LED)用Y3Al5O12(YAG)单晶荧光材料的制备和光谱性能进行了研究。采用提拉法生长了白光LED用Ce:YAG及Sm,Ce:YAG晶体,并通过吸收光谱、激发光谱和发射光谱等对晶体的光谱特性进行表征。结果表明:Ce:YAG单晶作为荧光材料被发射波长460 ...  相似文献   

9.
以色氨酸和邻苯二胺为前驱体,以乙醇和水为溶剂,采用溶剂热法制备氮掺杂碳点(N-CDs),基于N-CDs量子产率测试,考察n(色氨酸)∶n(邻苯二胺)和反应时间对制备N-CDs的影响,通过FTIR、XRD、TEM、XPS和TGA表征和测试N-CDs的形貌结构和热稳定性;利用荧光光谱、量子产率测定和荧光寿命测试探究N-CDs的光学性能。结果表明,当n(色氨酸)∶n(邻苯二胺)=1.5∶1、反应时间6 h时,制备的N-CDs展现出最高的量子产率(13.95%);N-CDs呈平均粒径3.65 nm的球形结构,表面富含氨基、羟基、羧基及羰基等极性官能团;N-CDs的最大激发波长和最大发射波长分别为535和601 nm,在535 nm处的绝对量子产率高达21.39%。N-CDs溶液在酸性条件下展现蓝色荧光,在碱性条件下则呈现粉色但无荧光,表现出对pH敏感的颜色和荧光响应性。  相似文献   

10.
掺杂铽的稀土酒石酸配合物的合成及其荧光性能研究   总被引:6,自引:0,他引:6  
采用溶液反应法合成了掺杂铽的稀土酒石酸配合物Ln2-xTbxL3(Ln=Y,La,Gd),通过无素分析,X射线粉末衍射及红外光谱等对其组成进行了表征,测定了该系统配合的荧光光谱,实验结果表明,该系列配合物的组成为Ln2-xTbxl3.6H2O(Ln=L,La,Gd),该掺杂配合物比单纯配合物Tb2L3具有更好的发光性能,而且当x=0.7-1.5时,该掺杂配合物的发光最强,据此探讨同多核稀土酒石酸配合物及杂多核烯土酒石酸配合物发光机理。  相似文献   

11.
In the present investigation, titania thin films doped with varying concentrations of Samarium (Sm) were synthesized by spin coating method on glass substrate. The obtained films were annealed at two different temperatures (350 and 450 ?C) to induce crystallinity. The structural property of these samples was characterized by using X-ray Diffraction (XRD) and Raman spectrometer. The surface morphology of the films was analysed by Field Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). The presence of pure anatase phase with enhanced polycrystalline nature was evident for the films annealed at 350 and 450 ?C. Due to the addition of Sm, the titania thin films exhibited increased crystallinity. The Raman analysis also support the presence of crystalline anatase phase and the existence of defects in the deposited films. The prepared samples were also subjected to photocatalytic activity studies by using methyl orange (MO) dye and the results are discussed herein. The rate constant increased and half life time decreased considerably for 0.4 at% doped samples. The current work provides new ideas for monitoring the structural properties by adding low concentration rare earth dopant into metal oxides (titania) suitable for various applications.  相似文献   

12.
    
《Ceramics International》2020,46(10):15822-15830
In this paper, Co-doped ZnO quantum dots (QDs) with smaller lateral size and high stability were prepared via a simple and one-step sol-gel method. We found that Co-doped ZnO QDs could more effectively absorb visible light and motivate the separation efficiency of photogenerated electrons and holes, resulting in the over yield production of superoxide anion (.O2-) and hydroxyl radical (.OH) under environmental condition. As a result, the antibacterial activity of Co-doped ZnO QDs was drastically improved than that of bare ZnO QDs, and the superoxide radicals mediated oxidative stress plays a dominant role in the antibacterial mechanism. Besides, controllable construction of smaller size Co-doped ZnO QDs was favoured for the contact between the nanoparticles and bacteria, thus significantly decreased the transmission path of ROS and Zn2+, causing the markedly enhanced antibacterial activities.  相似文献   

13.
谭艳芝 《广州化工》2007,35(3):5-7,14
量子点因具有宽的激发光谱、窄的发射光谱、高的荧光量子产率和寿命长等特殊的性质,是一种比荧光染料分子更理想的生物探针。详细介绍了国内外的几种量子点制备方法及其表面修饰,另外综述了量子点在生物学的应用。  相似文献   

14.
《Ceramics International》2023,49(3):4230-4239
The work focuses on exploring the effect of the concentration of Sm dopant (0.2–0.6 at.%) on structural, optical and photocatalytic properties of the spin coated titania based thin films annealed at different temperatures. The optical interpretation involves the influence of Sm doping on optical constants and luminescence behaviour of the samples. The comprehensive work on optical bandgap, Urbach energy and electron-phonon interaction strength was conducted for Sm doped samples. The optical band gap was found to increase with the increasing concentration of Sm, but decreased with high temperature annealing. Using ellipsometry measurement, refractive index of the samples was obtained. The orbital level information was gathered using X-Ray Photoelectron Spectroscopy (XPS) study with a special emphasis on the evolution of physico-chemical properties as function of Sm doping. The XPS study confirms the presence of Sm in the titania host material and it helped in estimating defects induced by Sm doping. The photocatalytic study of Sm doped titania thin films was carried out by using methylene blue (MB) and Rhodamine B (RhB) dye and we have found an enhanced photocatalytic activity for the 0.4 at.% Sm doped samples.  相似文献   

15.
This paper reports the preparation of three-dimensional ZnO spheres by using a hydrothermal method and their application to quantum dots sensitized solar cells (QDSSCs). After achieving the desired thickness of sensitized CdS quantum dots (QDs) for ZnO spheres, ZnS overlayer was deposited on the surface of CdS/ZnO photo-anodes to further improve the photoelectric properties. CdS QDs and ZnS overlayer were deposited by successive ionic layer adsorption and reaction (SILAR) method. The surface morphology and crystal structure of the samples were verified by field-emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The CdS QDs sensitized solar cells were ameliorated via using ZnS as a protection-layer between quantum dots and electrolyte. As a result, the power conversion efficiency (η) has been increased from 0.60 to 1.43% after being treated by ZnS overlayer for CdS/ZnO photo-anodes.  相似文献   

16.
采用固相合成法制备出具有不同x值的SmxCe4/5(1-x)Mo1/5(1-x)O(2-0.5x+δ)颜料,研究了Sm3+掺杂量对颜料晶体结构的影响,并对颜料呈色机理进行了分析。结果表明:Sm3+掺杂对颜料的颜色有较大的改变,Sm3+掺杂量从x=0到x=0.3时颜料为黄色,从x=0.36到x=0.5时颜料颜色由黄色向灰色转变。  相似文献   

17.
A universal and facile electrochemical etching method for synthesizing nanosized metal oxide semiconductors has been presented by taking the synthesis of ZnO quantum dots (QDs) from metallic zinc as an example. By applying an appropriate potential, metallic zinc was controllably oxidized to Zn2+ ion, the latter (Zn2+) was released into an organic electrolyte and hydrolyzed by trace dissolved water therein, giving rise to ZnO QDs. The electrochemically synthesized ZnO QDs were uniform particles with an average diameter of 5.0 nm, and exhibited good photoluminescent and electrochemiluminescent activities. The effects of applied potential window, amount of water and dissolved oxygen on the formation of ZnO QDs were investigated and discussed in detail. The presently proposed electrochemical etching method not only has provided a facile, low-cost and controllable way to obtain ZnO QDs, but also would be applicable as a universal method in synthesizing other kinds of nanosized metal oxide semiconductors from related metals.  相似文献   

18.
以高纯度的SrCO3、NH4VO3、Eu2O3和Yb2O3等为主要原料,采用高温固相法合成荧光粉。X-粉末衍射及荧光光谱证实合成了一种在可见光范围内有广泛吸收的发黄光的钒酸盐体系荧光粉。其中Eu3+的最佳掺杂摩尔浓度比为0.09,最佳煅烧温度为1223K。  相似文献   

19.
    
Co-doped ZnO-based ceramics using Al, Ti, and Mg ions in different ratios were synthesized with the objective to investigate the doping effects on the crystalline features, microstructure and the electrical behavior. For Al and Ti doping, a coexistence of crystalline phases was shown with a major wurtzite ZnO structure and secondary spinel phases (ZnAl2O4, Zn2TiO4, or ZnaTibAlcOd), while Mg doping did not alter significantly the structural features of the wurtzite ZnO phase. The electrical behavior induced by Al, Ti, and Mg co-doping in different ratios was investigated using Raman, electron paramagnetic resonance (EPR) and 27Al and 67Zn solid-state nuclear magnetic resonance (NMR). Al doping induces a high electrical conductivity compared to other doping elements. In particular, shallow donors from Zni-AlZn defect structures are inferred from the characteristic NMR signal at about 185 ppm; that is, quite far from the usual oxygen coordinated Al. The Knight shift effect emanating from a highly conducting Al-doped ZnO ceramics was considered as the origin of this observation. Oppositely, as Ti doping leads to the formation of secondary spinel phases, EPR analysis shows a high concentration of Ti3+ ions which limit the electrical conductivity. The correlation between the structural features at the local order, the involved defects and the electrical behavior as function of the doping process are discussed.  相似文献   

20.
利用溶胶-凝胶法合成了名义组分Zn0.993-xMn0.007LixO(x=0,0.005,0.02)粉晶,分别采用SEM,EDX,XPS,XRD,UV-VIS和VSM对样品的形貌、成分、晶体结构、光学特性和磁性进行了研究。结果表明:Li的引入明显提高了Zn0.993Mn0.007O的室温磁化强度。当x=0.005时,Li以间隙原子的形式进入ZnO晶格,结晶性能下降,磁化强度的提高归因于ZnO晶格间隙电子掺杂和缺陷,使Mn2+-Mn2+间接铁磁性交换耦合增强;当x=0.02时,Li以替代原子形式进入ZnO晶格,相对于x=0.005其结晶性能提高,磁化强度的提高归因于ZnO中空穴载流子的增加,空穴载流子来自于Li+的受主作用。  相似文献   

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