助熔剂NaCl－CdCl2对CdS∶Cu, In结晶状态作用规律研究

发现在确定的热处理温度和时间下，随炉料中助熔剂ＮａＣｌ－ＣｄＣｌ２总含量的增加，ＣｄＳ：Ｃｕ，Ｉｎ多晶的粒度分布变窄，数均粒径具有最大值，晶粒外型趋于规整且表面平滑。进而证明，多晶的结晶状态对其光电性能具有显著的影响。     

石墨炉原子吸收光谱中GdCl3,Gd（NO3）3基体的背景吸收

研究了石墨炉原子吸收光谱中ＧｄＣｌ３、Ｇｄ（ＮＯ３）３基体的背影吸收影响。背景吸收波长特性的研究表明，ＧｄＣｌ３和Ｇｄ（ＮＯ３）３的背景吸收都具有明显的波长特性。蒸发行为研究表明ＧｄＣｌ３的背景吸收主要来自ＧｄＣｌ３的分子蒸气，Ｇｄ（ＮＯ３）３的背景吸收主要来自ＮＯ。钆基体的背景吸收峰高与灰化有关，ＧｄＣｌ３背上曲线轮廓与原子化温度和原子化方式有关。Ｇｄ（ＮＯ３）３的背景吸收远小于ＧｄＣｌ３。本文     

钛层柱粘土的合成 Ⅰ．四氯化钛作钛源

由ＴｉＣｌ４／ＨＣｌ配制的含钛柱化剂与粘土进行阳离子交换后得到大孔钛层柱粘土（Ｔｉ－ＰＩＬＣ），详细研究了各种合成条件，诸如Ｔｉ（Ⅳ）及ＨＣｌ浓度，柱化剂老化时间，粘土初始浓度，交换温度及配料比等对层柱粘土的大孔及比表面积的影响．优化条件合成的Ｔｉ－ＰＩＬＣ存在两种晶面间距（ｄ００１），其中之一（２．５６ｎｍ）对应大孔结构．Ｔｉ－ＰＩＬＣ比表面积为３２８ｍ２／ｇ，５００℃焙烧后ｄ００１保持２．３２ｎｍ，６５０℃焙烧后比表面积仍达３０１．４ｍ２／ｇ．Ｔｉ－ＰＩＬＣ的大孔结构主要取决于交换时混合液中Ｔｉ（Ⅳ）和ＨＣｌ浓度，并与柱化剂老化时间、交换温度等因素有关；与原柱化剂中Ｔｉ（Ⅳ）和ＨＣｌ浓度无关．混合液中ＣＨＣｌ提高，Ｔｉ－ＰＩＬＣ的比表面积下降；当ＣＨＣｌ增至７０ｍｍｏｌ／Ｌ时，产物中大晶面间距消失，仅留下小晶面间距（～１．４ｎｍ）．随着混合液中ＣＴｉＣｌ４的提高，Ｔｉ－ＰＩＬＣ的比表面积先上升而后下降。当ＣＴｉＣｌ４增至１４６ｍｍｏｌ／Ｌ时，产物也仅有小晶面间距（１．４ｎｍ）．     

L—赖氨酸酯聚酰胺Gd（Ⅲ）配合物的合成

Ｌ－赖氨酸长链烷基酯与二乙三胺五乙酸双酸酐共缩聚，制得大分子配体，它与ＧｄＣｌ３反应得到相应的配合物．这些配合物具有比现在用于临床诊断的造影剂Ｇｄ（ＤＴＰＡ）更高的弛豫速率．     

微分电位溶出法连测血清中铜铅镉锌

报道了微分电位溶出法先在０．００２５ｍｏｌ．Ｌ＾－１ＨＣｌ－０．３ｍｏｌ．Ｌ＾－１ＮＨ４Ｃｌ底液中连测血清中Ｃｕ、Ｐｂ、Ｃｄ，再加Ｃａ＾３＋０．６μｇ、０．３ｍｌＮＨ４Ｆ（２ｍｏｌ．Ｌ＾－１）于底液，稀释一倍后测Ｚｎ。Ｃｕ采用标准曲线法，Ｐｂ、Ｃｄ、Ｚｎ采用标准加入法。在选定条件下，四元素的线性关系良好。测试血汪有相对标准偏差≤４．６％，平均回收率为９３．３％－１０１．３％，结果令人满意。     

用聚乙二醇—硫酸铵—铝试剂体系萃取分离铁（Ⅲ）铝（Ⅲ）,铜（Ⅱ）钴（Ⅱ）…

研究了在聚乙二醇－硫酸铵－铝试剂体系中Ｆｅ（Ⅲ），Ａｌ（Ⅲ）、Ｃｕ（Ⅱ）、ＣｏⅡ）Ｃｄ（Ⅱ）Ｍｎ（Ⅱ）、Ｎｉ（Ⅱ）的萃取分离行为。结果表明，在ＰＨ５．０－６．５ＨＡｃ－ＮａＡｃ缓冲溶液中，Ｆｅ（Ⅲ）、Ａｌ（Ⅲ）可被ＰＥＧ相几乎完全萃取，而Ｃｕ（Ⅱ）、Ｃｏ（Ⅱ）Ｃｄ（Ⅱ）Ｍｎ（Ⅱ）基本上不被萃取，从而实现了Ｆｅ（Ⅱ）与Ｃｕ（Ⅱ）Ｃｏ（Ⅱ）Ｃｄ（Ⅱ）Ｍｎ（Ⅱ)及Ａｌ（Ⅲ）与Ｆｅ（Ⅲ）Ｃｏ（Ⅱ）、Ｃｕ（     

铁钴镍铜锌镉铝在聚乙二醇—硫酸铵—茜素S体系中萃取分离

本文用茜素Ｓ作萃取剂，研究了Ｆｅ，Ｃｏ，Ｎｉ，Ｃｕ，Ｚｎ，Ｃｄ，Ａｌ在聚乙二醇－硫酸铵－茜素Ｓ体系中的非有机溶剂萃取行为。实验结果表明，在ｐＨ５的ＨＡｃ－ＮａＡｃ缓冲溶液中，Ｆｅ，Ａｌ与茜素Ｓ的络合物可被ＰＥＧ相几乎完全萃取，Ｃｕ，Ｎｉ部分被萃取，而Ｃｏ，Ｚｎ，Ｃｄ则不被萃取，从而实现了Ｆｅ与Ｃｏ，Ｚｎ，Ｃｄ及Ａｌ与Ｃｏ，Ｚｎ，Ｃｄ混合离子间的定量分离。     

钛层柱粘土的合成:I.四氯化钛作钛源

由ＴｉＣｌ４／ＨＣｌ配制的含钛柱化剂与粘土进行阳离子交换后得到大孔钛层柱粘土（Ｔｉ－ＰＩＬＣ），详细研究了各种合成条件，诸如Ｔｉ（Ⅳ）及ＨＣｌ浓度，柱化剂老化时间，粘土初始浓度，交换温度及配料比等对层柱粘土的大孔及比表面的影响。优化条件合成的Ｔｉ－ＰＩＬＣ存在的两种晶面间距（ｄ００１），其中之一（２．５６ｎｍ）大孔结构。Ｔｉ－ＰＩＬＣ比表面积为３２８ｍ＾２／ｇ，５００℃焙烧后ｄ００１保持２．３２ｎ     

三水合希土氯化物(镨、钆)与18－冠－6配合物的热化学研究

制备了ＲＥＣｌ３．３Ｈ２Ｏ（ＲＥ＝Ｐｒ，Ｇｄ）与１８Ｃ６的固态配合物，其化学组成为：ＲＥＣｌ３，１８Ｃ６．３Ｈ２Ｏ。对其进行了ＩＲ，溶解度、ＤＴＧ和ＴＧ分析，推测了热分解机理，测量了２９８．１５Ｋ时１８Ｃ６及两种配合物在无水乙醇中的积分，及ＲＥＣｌ３，３Ｈ２Ｏ在１８Ｃ６－Ｃ２Ｈ２ＯＨ溶液中的溶解配位热效应，依据本文所设计的热化学循环，求得了ＲＥＣｌ３，３Ｈ２Ｏ（ｓ）与１８Ｃ６（ｓ）生成ＲＥＣｌ３，     

三水合希土氯化物（镨、钆）与18－冠－6配合物的热化学研究

制备了ＲＥＣｌ３·３Ｈ２Ｏ（ＲＥ＝Ｐｒ、Ｇｄ）与１８Ｃ６的固态配合物，其化学组成为：ＲＥＣｌ３·１８Ｃ６·３Ｈ２Ｏ．对其进行了ＩＲ、溶解度、ＤＴＧ和ＴＧ分析．推测了热分解机理．测量了２９８．１５Ｋ时１８Ｃ６及两种配合物在无水乙醇中的积分溶解热，以及ＲＥＣｌ３·３Ｈ２Ｏ在１８Ｃ６－Ｃ２Ｈ５ＯＨ溶液中的溶解配位热效应．依据本文所设计的热化学循环，求得了ＲＥＣｌ３·３Ｈ２Ｏ（ｓ）与１８Ｃ６（Ｓ）生成ＲＥＣｌ３·１８Ｃ６·３Ｈ２Ｏ（Ｓ）的反应热及两种配合物的标准生成焓．     

Stability of CdS-coated TiO<Subscript>2</Subscript> solar cells

The obstacle to realize the large-scale production of dye-sensitized solar cells (DSSCs) is its long-term stability and reliability problem. One of the main causes of the instability of DSSCs is the use of liquid electrolytes. In addition, exploring nano-sized particles of CdS as an alternative sensitizer for organic dye in dye-sensitized solar cells have attracted great interest due to the high cost and the instability of the organic dye. Our study has found that the CdS-coated TiO₂ cell degrades rapidly in the liquid electrolytes even under dark environment. In this work, a solid-state solar cell structure of Glass/FTO/TiO₂/CdS:Cu/FTO/glass was successfully made with an efficiency of 0.7%. CdS:Cu served as both the p-type conductor and absorber. No efficiency was obtained for cell structures of glass/FTO/TiO₂/CdS/FTO/glass. This indicates the effectiveness of hole conducting behavior of CdS:Cu. This is the first time that this type of solid-state solar cell is reported and improved stability is demonstrated.     

聚乙烯吡咯烷酮修饰的CdS纳米晶：多元醇合成、表征和可见光活性

采用溶剂热法合成了具有不同晶粒尺寸的聚乙烯吡咯烷酮（PVP）修饰的CdS纳米晶,并运用XRD,N₂物理吸附,TEM,IR,UV-Vis等手段进行表征。结果表明,所制得的样品均为聚乙烯吡咯烷酮(PVP)修饰的CdS纳米晶;添加四甲基氢氧化铵(TMAH)有利于获得晶粒尺寸较小的CdS纳米晶;受纳米晶粒尺寸的影响,CdS纳米晶的吸收边发生蓝移且可见光催化活性明显提高。     

Formation of Twinned Graphene Polycrystals

Liquid metals have been widely used as substrates to grow graphene and other 2D materials. On a homogeneous and isotropic liquid surface, a polycrystalline 2D material is formed by coalescence of many randomly nucleated single‐crystal islands, and as a result, the domains in a polycrystal are expected to be randomly aligned. Here, we report the unexpected finding that only 30°‐twinned graphene polycrystals are grown on a liquid Cu surface. Atomic simulations confirm that the unique domain alignment in graphene polycrystals is due to the free rotation of graphene islands on the liquid Cu surface and the highly stable 30°‐grain boundaries in graphene. In‐depth analysis predicts 30 types of possible 30°‐twinned graphene polycrystals and 27 of them are observed. The revealed formation mechanism of graphene polycrystals on a liquid Cu surface deepens our fundamental understanding on polycrystal growth and could serve as a guideline for the controlled synthesis of 2D materials.     

Orange-red luminescence from Cu doped CdS nanophosphor prepared using mixed Langmuir-Blodgett multilayers

Cu doped CdS nanophosphors were fabricated through Langmuir-Blodgett route for the first time. Precursors mixed Langmuir-Blodgett multilayers of cadmium arachidate-copper arachidate were used to grow doped sulfide nanoparticles within the organic matrix through postdeposition treatment with H(2)S gas. Changes in composition and layered structure of precursor multilayers were studied using Fourier transform infrared and x-ray reflection. Uptake of Cu in the multilayers was analyzed by inductively coupled plasma atomic emission spectroscopy measurements. Unannealed H(2)S exposed multilayers containing CdS nanoparticles show strong surface state emission centered at approximately 570 nm, whereas Cu doped CdS nanoparticles show orange-red luminescence. Photoluminescence (PL) spectra of annealed-Cu doped CdS nanoparticles show distinct Cu-related emission compared to annealed-undoped CdS nanoparticles. Power dependent PL measurements of annealed samples show that an efficient carrier recombination takes place at T(2) level of Cu(++). The carrier relaxation from the excitonic states to T(2) level results in the strong orange-red luminescence.     

Effects of Dissipation on Contact Angle Measurements Using a Dynamic Method

We report studies of the effect of hydrothermal treatment on physical properties such as crystalline phase, size, and morphology of nanosized cadmium sulfide (CdS) particles. CdS precipitates have been synthesized by the reaction of Cd(NO(3))(2) with Na(2)S at room temperature. These CdS precipitates have been hydrothermally treated in the range 120-240 degrees C with variation of the treatment time. The effects of acid catalysts and other additives were also investigated. The particles prepared were characterized by XRD, TEM, and BET methods. With increased hydrothermal treatment temperature and time, crystallization from amorphous to crystalline form, cubic or hexagonal, and an increase of particle size occurred. CdS particles of well-developed hexagonal form were obtained at a hydrothermal treatment temperature of 240 degrees C; the primary hexagonal grain size was on the order of 20-30 nm. The addition of an acid catalyst, HCl, or of Cd(NO(3))(2) into the precipitate sol promoted crystal growth and phase transformation during the hydrothermal treatment, but another additive, Na(2)S, showed the opposite trend. It appears that hydrothermal treatment combined with proper additives could be an effective method for preparation of nanosize crystalline CdS particles. Copyright 2001 Academic Press.     

Studies on optical absorption and photoluminescence of thioglycerol-stabilized CdS quantum dots

Nanoparticles of CdS were prepared at 303 K by aqueous precipitation method using CdSO4 and (NH4)2S in presence of the stabilizing agent thioglycerol. Adjustment of the thioglycerol (T) to ammonium sulphide (A) ratio (T:A) from 1:25 to 1:3.3 was done during synthesis and nanoparticles of different size were obtained. The prepared colloids were characterized by UV-vis and photoluminescence (PL) spectroscopic studies. Prominent first and second excitonic transitions are observed in the UV-vis spectrum of the colloid prepared with a T:A ratio of 1:3.3. Particle size analysis was done using XRD, high resolution TEM and dynamic light scattering and found to be approximately 3 nm. UV-vis and PL spectral features also agree with this particle size in colloid with T:A of 1:3.3. The band gap of CdS quantum dots has increased from the bulk value 2.4-2.9 eV. PL spectra show quantum size effect and the peak is shifted from 628 to 556 nm when the ratio of T:A was changed from 1:25 to 1:3.3. Doping of CdS with Zn2+ and Cu2+ is found to enhance the PL intensity. PL band shows blue-shift and red-shift on doping with Zn2+ and Cu2+, respectively. UV and PL spectral features of the CdS/Au hybrid nanoparticles obtained by a physical mixing of CdS and Au nanoclusters in various volume ratios is also discussed. Au red-shifts and rapidly quenches the PL of CdS. An additional low energy band approximately 650 nm is observed in the UV visible spectrum of the hybrid nanoparticles.     

CdS量子点敏化ZnO纳米棒阵列电极的制备和光电化学性能

采用连续式离子层吸附与反应法制备了CdS量子点敏化的ZnO纳米棒电极.应用扫描电子显微镜(SEM)、X射线衍射(XRD)和透射电子显微镜(TEM)对CdS量子点/ZnO纳米棒电极的形貌、晶型和颗粒尺寸进行了分析和表征;采用光电流-电位曲线和光电流谱研究了不同CdS循环沉积次数及不同沉积浓度对复合电极的光电性能影响.结果表明,前驱体浓度都为0.1mol·L-1且沉积15次敏化后的ZnO纳米棒阵列电极光电性能最好.与单纯的ZnO纳米棒阵列电极和单纯的CdS量子点电极相比,其光电转换效率显著提高,单色光光子-电流转换效率(IPCE)在380nm处达到76%.这是因为CdS量子点可以拓宽光的吸收到可见光区,并且在所形成的界面上光生载流子更容易分离.荧光光谱实验进一步说明了光电增强的原因是,两者间形成的界面中表面态大大减少,有利于减少光生电子和空穴的复合.     

在CdS水悬浮液中O2光吸收的pH效应

为了深入了解间接光腐蚀过程, Grätzel等人曾考察过O₂在CdS和Rh₂0₃/CdS 悬浮液(pH=9)中光吸收行为, 发现光照生成的SO₄^2-的µmol数值基本上为加入O₂的µmol数值的一半, 且反应后悬浮液的pH降低^[3]。     

CdTe/CdS荧光探针测定痕量铜(Ⅱ)

以巯基乙酸为稳定剂,在水溶液中合成CdTe/CdS量子点,基于量子点与Cu2+混合后发生荧光猝灭作用,建立CdTe/CdS量子点作为荧光探针检测微量铜的新方法。在pH 4.60的HAc-NaAc缓冲溶液中,反应时间为10 min时,Cu2+质量浓度在0.01～1.00μg/mL范围与CdTe/CdS量子点的荧光猝灭程度呈良好的线性关系,相关系数为0.9978,检出限为9.90×10-3μg/mL。方法可以用于雨水、自来水和延河水中Cu2+的分析。