新型染料敏化体系—荧光素染料碘翁盐的光谱研究

本文合成了一系列荧光素类染料碘翁盐，并研究了其光谱及光化学性质。结果表明，通过改变结构，可改变它们的吸收光谱。提出可用ＩⅠ／ＩⅡ值来表征这类化合物在溶剂中的相对解离程度。随溶剂极性，染料母核Ｃ－６位周围（Ｃ－７，Ｃ－８位）空间位阻增大和染料母核上吸电子取代基增多，ＩⅠ／ＩⅡ值增大，它们的相对解离程度升高，光谱性质显著变化，光化学反应速度下降。在极性和非极性溶剂中，浓度对光谱和光化学性质具有不同的影     

呫吨染料－双（二苯基碘鎓盐)在高分子膜中的光谱和光化学特性

吨染料－双（二苯基碘盐）在高分子膜中的光谱和光化学特性＊周文慧李妙贞周华娥王尔＊＊（中国科学院感光化学研究所，北京１００１０１）关键词染料敏化，碘盐，电子转移，离子对近年来，在迅速发展的新材料中，许多品种是与激光技术和光化学反应密切相关的．而...     

染料敏化太阳能电池的研究进展

染料敏化太阳能电池（dye-sensitized solar cells,DSSC）由于工艺简单、价格便宜、转换效率高等优点而受到大量关注。本文介绍了染料敏化太阳能电池的基本结构和工作原理,综述了染料敏化太阳能电池的研究现状,论述了光阳极上半导体薄膜的制备、改性方法;阐述了敏化染料和氧化还原电解质的要求、特点和分类。指出高性能半导体薄膜、光谱响应宽稳定性好的敏化染料以及高效全固态电解质的研发与应用是今后的主要研究方向。     

提高染料敏化太阳能电池转化率研究新进展

染料敏化太阳能电池具有低生产成本、简单生产工艺以及环境友好型等优点,使其成为太阳能电池研究领域的热点。介绍了染料敏化太阳能电池的基本结构和工作原理,结合国内外最近的研究动态,重点阐述了在染料敏化太阳能电池研究领域的光阳极、敏化染料和电解质等构成部分的研究进展。     

溴化银晶体光谱敏化光电流的研究和染料增感性能的判据

本文以AgBr晶体和菁染料为对象,对AgBr晶体的光电流进行了研究。实验发现,AgBr晶体经其本征吸收波长的光辐照后,可产生新的诱导吸收带。用诱导吸收带波长范围内的光辐照AgBr晶体,在非本征吸收区可测量到自敏化光电流。若染料吸附在AgBr晶体片上,则其敏化光电流将叠加在自敏化光电流上。增感染料对AgBr晶体的阳极和阴极光电导均有不同程度的敏化作用。本文在实验研究的基础上,提出了对染料增(减)感性能的判据S_D,比现有的一些判据更具有综合性。利用S_D—λ曲线可以较直观地对染料的增(减)感性能做出预测。本文利用S_D判据对一些实用增感染料及其组合作了分析。     

二元离子液体基染料敏化太阳能电池性能的研究

对6种用于染料敏化太阳能电池的二元离子液体电解质进行了考察,电池的光电转化效率在1.39%～4.98%,其中,1-乙基-3-甲基咪唑四氟硼酸盐/碘化1-丁基-3-甲基咪唑类电解质具有最高的光电转化效率。对这种二元离子液体电解质体系进一步优化,测试了不同碘浓度下相应染料敏化太阳能电池的效率、电化学阻抗谱(EIS)和紫外-可见吸收光谱(UV-vis)。结果表明,随着碘单质浓度的增大,铂-电解质界面的传荷电阻(RPt)、TiO2-电解质表面的传荷电阻(Rct)和瓦尔堡阻抗(Zw)逐渐减小,而电解质对紫外光的吸收逐渐增大,在AM1.5的条件下,当碘单质的浓度为0.25 mol/L时电池效率最高,达到5.20%。     

离子液体聚合物电解质在染料敏化太阳能电池中的应用

离子液体以其高稳定性、高导电性等特有的优点成为众多领域的研究热点。本文综述了离子液体聚合物电解质在染料敏化太阳能电池中的应用,详细讨论了离子液体聚合物电解质的复合方法,并比较了复合前后电解质的电导率情况;评论了复合离子液体聚合物电解质在多方面的应用,并对其发展方向进行了展望。     

1-丁基-3-甲基咪唑碘对染料敏化太阳电池的影响

采用季铵化反应合成了1-丁基-3-甲基咪唑碘([Bmim]I).以此制备了DSCs用液体电解质.通过对比不同浓度的1-丁基-3-甲基咪唑碘、碘化钾、碘,研究其对电池性能的影响.经过优化后,当cIL=0.9 mol.L-1、cKI=0.5 mol.L-1、cI2=0.12 mol.L-1时,所组装的离子液体DSCs在AM1.5,100 mW.cm-2下,DSCs的短路电流密度为15.97 mA.cm-2、开路电压为0.71 V、填充因子为0.55、光电转换效率可达6.34%.     

染料敏化纳米晶太阳能电池的研究进展

染料敏化太阳能电池是近些年发展起来的新型、高效、低成本的光电池。而起到负载敏化剂以及收集、传输电子作用的光阳极是关系到该电池性能的重要组成部分,且敏化的效果是整个光电池光电转换效率的关键。从染料敏化纳米晶太阳能电池（DSSD s）的结构和工作原理出发,详细阐述了光阳极敏化、敏化剂选择及分类和敏化方法,并对光阳极及其敏化的可能发展趋势做了简要叙述。     

Changes in physicochemical properties of active carbon within a grain

Commercial active carbons were subjected to abrasion in a spouted bed and as a result, active carbons, with external layers removed to different degrees, were obtained. For active carbons so obtained, physicochemical properties were determined from densimetric and adsorption investigation.It was found that radial changes in the properties of active carbons resulted from the nature of the activation reaction.It seems that the method of working by abrasion in spouted beds can also be used for investigating other processes taking place in fluid—solid system.     

Effect of the addition of fluoride on the conditional solubility of alumina in LiCl-KCl eutectic melt

Owing to its well-known high complexing power toward Al³⁺ ion, fluoride ion is able to increase the solubility of alumina in alkali chloride melts. To determine the extent of this effect, the formation of aluminium(III) fluoro-complexes was studied potentiometrically in LiCl-KCl eutectic at 470°. But the sodium fluoride addition appeared to produce not only the complexation effect but also a mineralization effect on alumina. So, the thermodynamical stability of alumina formed in this melt by precipitation from aluminium chloride with carbonate ion (oxide anion donor) depends on the fluoride ion concentration. These two effects explain the solubility variation of alumina in the LiCl-KCl eutectic + NaF mixtures. A pF^? - pO^2? diagram, which represents the stability area of the various aluminium (III) species is established, and leads to some conclusions concerning the electrowinning of aluminium from molten chloride melts.The cumulative formation constants of the aluminium(lII) fluoro-complexes (AlF^3?i_i) have been obtained, whose values are the following: 2.5 ± 0.4, 4.7 ± 0.6, 5.7 ± 0.5, 7.5 ± 0.4, 8.0 ± 0.5, 9.0 ± 0.6, respectively for i = 1, 2, 3, 4, 5 and 6. It has been shown that oxyfluoride species such as AlOF^1?j_i does not exist. The solubility products of gamma and alpha-alumina have been determined and are equal to 10^?42.9 and 10^?44.0 respectively (all the constants are given in the molality scale). They differ widely from the solubility product of the alumina obtained in the absence of fluoride ion, ie 10^?27.4.     

Production of zinc ferrite in a mechano-chemical reaction by grinding in a ball mill

Zinc ferrite was obtained by prolonged dry grinding of stoichiometric powder mixtures of ZnO + -Fe₂O₃ or ZnCO₃ + -Fe₂O₃. The kinetics of transformation was studied by X-ray diffraction, Mössbauer spectroscopy and DTA. Crystallite size reduction followed the process, and defect structures resulted. The carbonate decomposed as a necessary step in the process. In the mixture of NiO + -Fe₂O₃, nickel ferrite was not obtainable, although considerable grain size reduction was observed. This was attributed to the inverse spinel configuration of the nickel ferrite, differing from the normal spinel configuration of the zinc ferrite. In the -Fe₂O₃ and the zinc ferrite, iron ions occupy octahedral sites, while in ZnO and the ferrite, zinc ions occupy tetrahedral sites, and metal ion—oxygen distance is almost identical. These facilitate the transformation. In the nickel ferrite, iron ions occupy both sites, which calls for high strains of -Fe₂O₃ before it can undergo transformation. Further implications of the processes are discussed.     

Multivariate statistical analysis of solids mixing

The applicability of multivariate statistics to the analysis of mixing processes and mixtures of multicomponent solid particles in a drum mixer has been successfully demonstrated. The applications include (1) test of sampling techniques, (2) test of the completely random state, (3) test of the completely segregated state, and (4) definition of a mixing index for a multicomponent mixture.     

Stereochemistry and mechanism of the hydrogenation of dialkyl cyclohexenes

In order to investigate the steric effect of the substituents to determine the product distribution, disubstituted cyclohexenes were hydrogenated over several transition metal catalysts. Some cyclohexenes which have two large substituents at the vicinal carbon atoms, at least one of which is trigonal, were not hydrogenated over Raney Ni at all but were hydrogenated over Pt catalyst under our experimental conditions. Presumably, the stereoselectivity depends on the competitive operation of the torsional angle strain and the catalyst hindrance with substituents. In the hydrogenation over Pd catalyst, thermodynamically more stable products were dominant at the standard condition but at high substrate to catalyst ratio the less stable products were slightly preferred. No appreciable stereoselectivity was observed in the hydrogenation of 1,4-disubstituted cyclohexenes.     

Pressure fluctuations and choking criterion for vertical pneumatic conveying of fine particles

Pressure fluctuations and bed voidages are obtained in the dilute phase flow and dense phase flow regimes of vertical pneumatic conveying systems of fine particles. Statistical parameters of the pressure fluctuations are utilized to study the transition from the dilute phase flow to the dense phase flow. Out of the four types of fine particle used in the experiments, three types of fine particle exhibit a choking transition, which is characterized by a sharp change in the bed voidage. At the choking transition, sharp changes in the power spectral density function and standard deviation of the pressure fluctuations are also observed. The fourth type of fine particle does not exhibit any sharp changes in bed voidage, power spectral density function, or standard deviation of the pressure fluctuations over a wide range of air velocities used in the experiments. It is shown that the power spectral density function and the standard deviation of pressure fluctuations can be effectively used to accurately determine the choking transition. The experimentally determined choking velocities and bed voidages in the slugging dense phase flow are compared with available correlations.     

The hydrogen electrode reaction characteristics of thin film electrodes of Ni-based hydrogen storage alloys

Film-type electrodes of hydrogen absorbing intermetallic compound and alloys, LaNi₅, Ni_0.11 Ti_0.89, Ni_0.50 Ti_0.50 and Ni_0.76 Ti_0.24 were prepared by a flash evaporation method. The hydrogen electrode reaction characteristics of the LaNi₅ and NiTi alloy films in 1 M NaOH are very similar to each other. The reaction proceeds via the Volmer-Tafel reaction route with mixed rate-determining characteristics. The exchange current densities of the constituent steps, as well as the overall reaction, are in the range of 10^?6 A cm^?2 (true). Surface analysis by an XPS technique has shown that La or Ti on the electrode surface exists as an electrocatalytically innert oxide of La₂O₃ or TiO₂. Close similarities of these electrodes with pure Ni electrodes indicate that Ni is responsible for the electrocatalytic activity. No synergistic effect is thus noticeable.