共吸附剂修饰TiO2电极及其在染料敏化太阳电池中的应用

在染料敏化太阳电池中, 引入共吸附剂通常有抑制染料聚集和提高电池性能的作用. 通过光谱电化学、线性伏安扫描和电化学阻抗谱(EIS)研究了几种以单羧酸基为吸附基团的共吸附剂对纳米TiO₂薄膜的修饰作用. 结果表明本实验中的共吸附剂均能使TiO₂平带电势负移, 并抑制TiO₂导带电子的复合, 其中胆酸类共吸附剂表现出较好的暗电流抑制性能. 适当浓度共吸附剂的引入能够提高N719染料敏化太阳电池的开路电压、填充因子和光电转换效率.     

共吸附剂修饰TiO2薄膜电极

共吸附剂修饰纳晶TiO₂薄膜电极是目前染料敏化太阳电池研究的一个热点. 本文通过平带电势和电化学阻抗研究了二(3,3-二甲基丁基)次膦酸和鹅脱氧胆酸两种共吸附剂修饰对TiO₂薄膜电极的平带电势和电极表面钝化能力的影响及其在染料敏化太阳电池中的应用. 结果表明, 二(3,3-二甲基丁基)次膦酸能更有效地钝化TiO₂薄膜表面, 并使TiO₂薄膜平带电势负移. 电化学阻抗谱测试结果表明, 在染料敏化太阳电池中, 相对于鹅脱氧胆酸, 二(3,3-二甲基丁基)次膦酸能更显著地提高器件的电子寿命和开路电压.     

染料敏化太阳电池中TiO2/染料/电解质界面的修饰

染料敏化太阳电池(DSC)作为新型太阳电池自问世以来受到了广泛关注, 其系统内部的接触界面尤其是TiO₂/染料/电解质界面一直是该领域的研究热点. 光敏染料的吸附以及电子的注入、传输和复合都发生在该界面, 其界面性质对DSC性能具有很大影响. 对染料敏化太阳电池中TiO₂/染料/电解质界面进行修饰可以有效抑制染料聚集和电子复合, 提高电子的注入效率与传输速率; 同时, 对TiO₂导带边的位置及染料吸附等也产生一定的影响, 最终提高电池的光电转换效率和稳定性. 本文主要从不同的修饰途径详细评述了TiO₂/染料/电解质界面修饰方法及机理研究进展,包括TiO₂光阳极的修饰改性、染料溶液中共吸附剂的引入和多种染料共敏化处理以及电解质中不同功能添加剂的应用. 指出了这些修饰方法目前存在的主要问题, 并对未来的发展方向进行了展望.     

染料敏化太阳电池电解质

染料敏化太阳电池是新一代的太阳电池,有着巨大的应用前景。其中电解质体系是电池组成的主要部分,对电池的性能有着重要的影响。本文介绍了染料敏化太阳电池的基本原理,详细评述了近几年国内外学者对染料敏化太阳电池用电解质体系的研究进展情况,根据电解质的存在状态将其分为液态、准固态和固态三大类并逐一进行介绍,最后对该领域的前景进行了展望。     

长链双烷基次膦酸作为共吸附剂修饰TiO_2光阳极

对TiO2/染料/电解质界面进行修饰是提高染料敏化太阳电池(DSC)性能的有效手段,其中引入共吸附剂有机小分子和染料共同吸附在TiO2表面是一种简单有效提高DSC性能的方法.本文合成了长链的双正十二烷基次膦酸(DDdPA)作为染料的共吸附剂应用于染料敏化太阳电池.通过红外光谱(FT-IR)表征DDdPA在TiO2表面的吸附;借助电化学阻抗谱(EIS)及强度调制光电流谱(IMPS)/强度调制光电压谱(IMVS)等技术表征了电子的传输与复合动力学过程.研究发现,DDdPA可以很好地与染料共同吸附在TiO2表面;与二(3,3-二甲基丁基)次膦酸(DINHOP)相比,DDdPA的引入可以更好地抑制TiO2/染料/电解质界面处的电子复合;在优化浓度配比下,DDdPA的引入有效提高了器件的电子寿命,使TiO2导带边负移约30 mV,最终使器件的开路电压提高了47 mV,光电转换效率提升约10%.     

染料敏化纳米薄膜太阳电池中的染料敏化剂

简要介绍了化学太阳电池的原理和染料敏化剂的发展历史,将现有染料敏化纳米薄膜太阳电池(简称DSCs)中的染料敏化剂分为有机和无机两大类,详细介绍了其中的羧酸多吡啶钌、膦酸多吡啶钌、多核联吡啶钌染料和有机染料的研究进展;介绍了其它染料敏化剂和多种染料协同敏化的研究现状;评述了染料敏化剂在染料敏化纳米薄膜太阳电池中应用的研究进展。     

有机染料及其在染料敏化太阳电池中的应用

在染料敏化太阳电池中,染料敏化剂分成无机染料与有机染料两大类。无机染料受稀有金属钌的制约而成本较高,开发有机染料是降低染料敏化太阳电池成本的有效手段,成为目前研究的热点。本文从有机染料敏化剂的分子设计入手,简述了染料敏化太阳电池中有机染料敏化剂的基本结构,将有机染料敏化剂分为吲哚啉类染料、香豆素类染料、三苯胺类染料、菁...     

有机小分子胶凝剂在准固态染料敏化太阳电池中的应用

染料敏化太阳电池(DSC)作为一种新型薄膜太阳电池,因具有价格低廉、高效等特点,受到各界的广泛关注。电解质作为DSC的主要组成部分,对电池效率和稳定性等性能有着重要的影响。本文简述了DSC工作原理及DSC用液态、固态及准固态电解质,从有机溶剂液态电解质和离子液体电解质两个方面,详细评述了有机小分子胶凝剂在准固态染料敏化太阳电池中的研究进展,并对其在准固态染料敏化太阳电池中的应用前景进行了展望。     

染料敏化太阳电池中的电子传输及复合*

电子传输与复合是染料敏化太阳电池中仍然存在争议的基本物理过程,解决这些争议对于进一步提高染料敏化太阳电池的光伏性能及稳定性是至关重要的。多缺陷理论模型用扩散系数及电子寿命这两个基本物理量准确地描述了染料敏化太阳电池中的电子传输及复合。为了对扩散系数及电子寿命等物理参数进行实验测量,近年来,人们发展出了频域、时域以及稳态等多种实验方法和技术手段,本文对这些方法进行了综述,并分别从纳晶半导体光阳极、电解质以及敏化染料等方面评述了近年来电子传输及复合的相关研究进展。     

不同受体结构染料共敏化对染料敏化太阳电池性能的影响（英文）

为了拓宽染料敏化太阳电池对太阳光谱的响应范围,提高电池的光电转换效率,将两种含有不同受体结构(绕丹宁-3-乙酸基(RA)和氰基丙烯酸基(CA))的三苯胺染料(TR1和TC1)进行共敏化。TR1染料平伏吸附在TiO_2表面,而TC1染料直立吸附在TiO_2表面。将两种染料按照不同摩尔比共敏化TiO_2后,TC1占据TR1的部分位置,拓展光谱的同时也抑制了电荷复合,电子寿命较TR1敏化的太阳电池长。在TR1与TC1摩尔比为5∶5的共敏剂溶液敏化的共敏电池器件中,短路光电流密度(J_(sc))为11.7 mA/cm~2,开路电压(V_(oc))为704 mV,填充因子(FF)为0.73,光电转换效率(η)为6.03%。该结果明显优于单一染料敏化的电池器件。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.