功能性三甲川菁染料的合成及其光电性质研究

设计合成了三种三甲川吲哚菁染料,其中2种染料含有活性官能团羧基,采用高分辨质谱、核磁1H、元素分析等方法对染料Cyb3的结构进行了表征。染料在溶剂中,随着溶剂极性的增强,最大吸收及发射波长都减小,呈弱的负向化显色效应。测试了染料Cyb3在甲醇溶液中的循环伏安曲线,通过Cyb3染料的氧化还原电位值和吸收光谱截止波长,计算出染料的最低激发态能级和TiO2的导带匹配,染料给出电子而被氧化的驱动力是1.35 eV。     

TiO_2形状对染料敏化太阳能电池性能的影响

第三代太阳能电池,即染料敏化太阳能电池(DSSCs)是由纳米多孔半导体薄膜(如TiO2)、有机染料敏化剂、氧化还原电解质(如I3-/I-)、对电极和导电基底等几部分构成。不同的TiO2的形状及构造对电池性能有着很大的影响。     

染料敏化太阳能电池中TiO_2光阳极的包覆效果

采用原位包覆和浸泡包覆在染料敏化太阳能电池的TiO2光阳极表面包覆了一薄层Al2O3,MgO或ZnO,讨论了不同包覆方法和实验条件对染料敏化太阳能电池性能的影响。研究表明,无论是原位包覆还是浸泡包覆,都可以在TiO2光阳极表面均匀的形成一层厚度约为1～2nm的氧化物包覆层,抑制了TiO2光阳极中的光生电子与氧化态染料和氧化态电解质的复合,从而导致光电压都有明显增大。特别是浸泡包覆不仅可以提高光电压,而且在较大的TiO2浆料粒径、合适的前驱体溶液浓度下,还可以增加光电流,导致光电转换效率明显增加。     

导电碳黑连接TiO2和染料分子提高染料敏化太阳能电池的光电性能

通常,染料敏化纳米太阳能电池(dye-sensitized solar cells,DSSCs)使用纳米金属氧化物来作为光阳极,如纳米TiO2,作为N型半导体通过连接染料来建立光阳极的。在光阳极中金属氧化物连接染料使DSSC的吸收光谱扩展到可见光谱区。文章研究在光阳极中添加导电碳黑使其成为纳米TiO2和染料之间的纽带。实验中使用粉末涂敷法在透光率约90%导电玻璃上涂覆纳米TiO2层在450℃烧结30 min,自然冷却然后再浸在染料和碳黑的混合物中敏化制得光阳极。添加的导电碳黑起到催化剂的作用,有助于染料电子的激发和纳米TiO2导带的增加并且减小了复合阻抗。结果表明,添加0.05 g导电碳黑的DSSCs光电性能最佳。开路电压增加了约33.9%,短路电流密度从4.385 mA/cm2增加到7.637mA/cm2。     

两种芴类敏化染料的合成及光电性能研究（加急）

将噻吩和呋喃通过缩合反应分别连接到芴的9位,再通过Vilsemier反应,对芴上噻吩或呋喃的2位进行甲酰化,最后与腈乙酸进行Knoevenagel反应,连接上锚定基团,得到两种以芴作为供电基团,以噻吩或呋喃作为π桥的染料F-S和F-O。所有的产物及中间产物均进行了~1HNMR验证。测试两种染料的光学性能后发现,虽然两种染料在结构上仅仅是一个原子之差,但是染料F-O的紫外-可见吸收光谱的最大吸收波长相对于染料F-S红移了20 nm。随后组装成电池测试其光电转换性能,结果发现染料F-O的光电转换效率(η)达到了2.76%,而染料F-S的光电转换效率仅仅为1.98%。这说明:引入合适的π桥能够大大地提高芴类染料的光电性能。     

新型D-π-A结构的分子设计及理论研究

应用D-π-A结构理论设计了一类以吖啶酮衍生物为电子供体的新型化合物,并采用密度泛函理论方法初步研究了这类新型有化合物的前线分子轨道。研究表明:化合物Ⅱ、Ⅲ具有较好的分子内电荷转移现象,且三种化合物的激发态能级均高于TiO2导带的能级(-4.40 eV),这些化合物能够作为太阳能电池中的染料敏化剂。     

Ti-凹凸棒石催化剂对染料废水的臭氧氧化降解的影响

对于生物难降解性有机染料废水 ,用臭氧氧化法进行处理可取得较好的效果。氧化效率低 ,处理成本高是臭氧技术实际应用中的主要障碍。采用凹凸棒石为载体加载钛氧化物制成的可重复使用的固体催化剂 ,对人工模拟染料废水进行复合催化氧化处理 ,取得了较好的效果。在pH =11,人工合成染料废水浓度为 40 0mg·L- 1 的条件下 ,m(TiO2 )∶m(凹凸棒石 )为 1∶2 0的Ti-凹凸棒石催化剂使臭氧氧化效率 (以COD去除率计 )从 2 1.5 %提高到 73.8%。催化效果在碱性条件 ( pH =11)和低浓度废水 ( 40 0mg·L- 1 )时效果较好。重复使用 3次后 ,TiO2 流失率和COD去除率都较满意     

染料的结构对太阳电池性能的影响

讨论了染料敏化纳米薄膜太阳电池中染料的结构对其性能的影响, 着重分析了染料的吸附功能基团、取代基效应和配体对染料光电化学性质的影响.研究表明,决定染料光电性质的主要是染料与TiO2薄膜电极表面之间的相互作用.在联吡啶钌染料中,羧酸取代基的染料与TiO2薄膜表面的相互作用最强,而且羧基的取代位置在4,4' 位, 配体为-NCS时染料的光电性能最好.     

TiO2光催化氧化法处理染料废水的研究

采用TiO2光催化氧化法处理染料废水,讨论TiO2投加量、废水初始pH和光照时间对废水的CODCr去除率和脱色率的影响。结果表明:各因素对CODCr去除率影响程度的顺序为TiO2投加量>pH>光照时间;最佳反应条件为TiO2投加量3 g/L,pH=6.00,光照时间60 min;在最佳条件下,废水的CODCr去除率达到63.75%,色度去除率达到89.9%。TiO2光催化氧化法对染料废水的有效处理具有可行性。     

含异靛单元染料的合成及在DSSC中的研究

我们以三苯胺为电子给体,氰基丙烯酸为电子受体和锚定基团,首次使用窄带隙共轭单元异靛设计合成了一个D-π-A型全有机染料TPAID1,对其进行在染料敏化太阳能电池中的性能进行了一些列的表征,测定了染料在氯仿溶剂中的紫外-可见吸收光谱,并对其进行了DSSC器件表征,在AM 1.5 G,100 mW/cm2下,染料TPAID1的电池能量转换效率为0.59%(Jsc=1.59 mA/cm2,Voc=0.55 V,FF=0.69)。     

Effect of different electron donating groups on the performance of dye-sensitized solar cells

A series of organic sensitizers containing identical π-spacers and electron acceptors but different, aromatic amine electron-donating groups, were used in dye-sensitized solar cells to study the effect of the electron donating groups on device performance. The derived photophysical and photovoltaic properties, as well as density functional theory calculations, revealed that the tetrahydroquinoline dye was prone to aggregate upon the surface of titanium dioxide owing to the dye's planar structure. A 45% improvement in efficiency of a tetrahydroquinoline dye based cell was achieved when chenodeoxycholic acid was employed as co-adsorbent. However, the airscrew type of triphenylamine unit and Y type structure of the substituted phenothiazine framework suppressed dye aggregation on titanium dioxide. The efficiency of a phenothiazine dye-based cell fabricated using saturated co-adsorbent in dichloromethane was only 15% greater than that achieved in the absence of co-adsorbent. Electrochemical Impedance Spectroscopy was used to determine the interfacial charge transfer process occurring in solar cells that employed different dyes in both the absence and presence of chenodeoxycholic acid as co-adsorbent.     

Effects of different acceptors in phenothiazine-triphenylamine dyes on the optical, electrochemical, and photovoltaic properties

In dye-sensitized solar cells (DSSCs), as the excited electrons from dye molecules are injected to the conduction band of semiconductor film through the acceptor moieties, the acceptor groups have significant influences on the photovoltaic properties of the dyes. In this paper, the effects of different acceptor groups (cyanoacetic acid and rhodanine-3-acetic acid) in two phenothiazine-triphenylamine dyes (PTZ-1 and PTZ-2) on the optical, electrochemical properties and photovoltaic performances were studied. In comparison with PTZ-2, the photovoltaic performance of PTZ-1 is significantly improved by replacing rhodanine-3-acetic acid to cyanoacetic acid. The conversion efficiency of solar cell based on the PTZ-1 is increased about 110%. The lower efficiency of solar cell based on PTZ-2 is mainly because the delocalization of the excited state is broken between the 4-oxo-2-thioxothiazolidine ring and the acetic acid, which affects the electron injection from PTZ-2 to the conduction band of TiO₂.     

Novel Self-assembled Isonicotinic Acid Derivative and Zinc Porphyrin Dyads and Applications in Dye Sensitized Solar Cells

A new self-assemblies based on double-deck dyes ZnTPP-Wi (i?=?1–3) were synthesized and applied in dye-sensitized solar cells (DSSCs). Anchoring molecules (Wi i?=?1–3) consisting of phenyl carboxyl acid and cyanoacetic acid group. Capping layer dyes zinc meso-tetraphenylporphine (ZnTPP) with anchoring molecules Wi through axially coordination bonds of Zn-to-ligand self-assemblies solar cells devices. We herein report a consisting acylamide and cyanoacetic acid group W3 as an anchoring molecule for the axial coordination with upper zinc porphyrin ZnTPP. W3 was synthesized by introducing acylamide and cyanoacetic acid groups may inhibit adverse dye aggregation and improving electrons are effectively injected into the TiO₂ semiconductor surface. Thus, W3 anchoring molecules can be used to fabricate efficient solar cells with ZnTPP porohyrin dye, achieving good photoelectric performance, indicative of their general applicability in fabricating good-performance DSSCs. The assembled modes were also verified by transmission electron microscopy (TEM). The photoelectrochemical efficiencies for dye ZnTPP-W3 are best than those of self-assembly dyes prevailingly ascribed to larger J_sc and V_oc.

     

Dithizone,carminic acid and pyrocatechol violet dyes sensitized metal (Ho,Ba& Cd) doped TiO2/CdS nanocomposite as a photoanode in hybrid heterojunction solar cell

Considering the great importance of nanocomposite based photo-active nanomaterials for a variety of electronics, photonics and photovoltaics application, it is always worth considering to synthesize new hetreostructure. This paper describes the sol-gel and hydrothermal synthesis of metal (holmium, barium, and cadmium) doped TiO₂/CdS nanocomposites for photoanode applications. Various characterization techniques, including XRD, FTIR, UV–VIS, EDX, and SEM were used to examine the synthesized heterostructures. The band gap of pure TiO₂ NPs is 3.10 eV, which was effectively decreased to 2.16 eV by doping and coupling with CdS. The nanomaterial's crystallinity, crystallite size, morphology and elemental composition were determined by XRD, SEM and EDX, respectively. As sensitizers, the organic dyes dithizone, carminic acid, and pyrocatechol violet were used. FTIR was used to analyze the effective dye grafting on the surface of nanomaterials. In the presence of hole conducting P3HT polymer as solid state electrolyte, the sensitized materials were evaluated for solid state dye-sensitized solar cells. Compared to the reference device, Cd–TiO₂/CdS photosensitized using Pyrocatechol violet dye demonstrated the highest efficiency of 2.68% (0.82%). Other parameters of this device, including open circuit voltage (Voc) and short circuit current (Jsc), were determined to be 16.97 mA cm² and 0.41V, respectively.     

Novel fluoranthene dyes for efficient dye-sensitized solar cells

Three, novel, fluoranthene-based dyes, 2-cyano-3-(5-(7,12-diphenylbenzo[k]fluoranthen-3-yl)thiophen-2-yl)acrylic acid, 2-(5-((5-(7,12-diphenylben-zo[k]fluoranthen-3-yl)thiophen-2-yl)methylene)-4-oxo-2-thioxothiazolidin-3-yl)acetic acid and 2-cyano-3-(4-(2-(7,12-diphenylbenzo[k]fluoranthen-3-yl)ethynyl) phenyl) acrylic acid, were synthesized for application as sensitizers in dye-sensitized solar cells. In each dye, the 7,12-diphenyl-benzo[k]fluoranthene moiety acted as electron donor with phenyl and thiophene units as electron spacers and carboxylic acid as electron acceptor. Tuning of the HOMO and LUMO energy levels was conveniently accomplished by changing the spacer and acceptor moiety, as confirmed using electrochemical measurements. Maximum solar energy:electricity conversion efficiency was 4.4% under AM 1.5 solar simulator (100 mW cm^?2) for 2-cyano-3-(5-(7,12-diphenylbenzo[k]fluoranthen-3-yl)thiophen-2-yl)acrylic acid. The results suggest that dyes based on fluoranthene donor are promising candidates for high performance, dye-sensitized solar cells.     

A Novel Alkoxysilyl Azobenzene Dye Photosensitizer with Alkylamino Group for Dye-Sensitized Solar Cells

A newly designed alkoxysilyl azobenzene dye with alkylamino group, 4-diethoxyphenylsilyl-4′-dimethylaminoazobenzene, was synthesized and examined as the photosensitizer for a dye-sensitized solar cell (DSSC). The novel azobenzene dye exhibited a strong absorption band in the visible region, and the solar cell using the dye as the sensitizer showed an incident monochromatic photon-to-current conversion efficiency (IPCE) value of 66 % at 440 nm and a light-to-electric energy conversion efficiency of 2.2 % under simulated sunlight irradiation of AM-1.5G one sun condition. The energy conversion efficiency obtained here is the highest value among those reported so far for azobenzene-sensitized solar cells, indicating the potential of alkoxysilyl dyes as photosensitizers for DSSCs.     

Effect of side chain substituents on the electron injection abilities of unsymmetrical perylene diimide dyes

Three near-infrared (NIR) absorbing unsymmetrical perylene diimide D-A-D type dyes containing 6-undecanoxy as donor group were utilized in dye-sensitized nanocrystalline TiO₂ solar cells. Structure of the acceptor side of the molecules were improved by adding 4-[2-methyl-5-(cyanoacrylic acid)-3-thienyl]-phenyl (V), 3-carboxy-2-pyridil (VI) and 3-carboxy-2-pyrazyl (VII) moieties attached to one of the N-side of the dye. The relationship between the molecular structure of the acceptor sites of the dyes and the photovoltaic performances were discussed. Electrochemical measurements indicated that band gaps of the dyes were energetically favorable for electron injection from the excited state of the dyes to the conduction band of TiO₂ nanoparticles. However, three dyes gave lower conversion efficiency on DSSC applications. Strong electron-withdrawing nature of perylene core might not permit to transfer the photo-generated electrons to the carboxyl groups anchoring to TiO₂ surface, and then solar-to-electricity conversion efficiencies of the dyes were reduced.     

草酸青霉Penicillium oxalicum菌体吸附活性染料的性能及微观过程

研究了草酸青霉(Penicillium oxalicum)在模拟染料废水中以边生长边吸附的方式对活性翠蓝KN-G, M-GB, K-GL,活性黑K-BR、活性艳蓝M-BR、活性红紫K-3R和活性深蓝K-R 7种水溶性活性染料的脱色性能及吸附过程. 结果显示,生长菌体对7种活性染料具有良好的脱色性能,染料初始浓度为200 mg/L时,平均脱色率可达93.0%;染料初始浓度为400 mg/L时,活性翠蓝KN-G和M-GB的脱色率仍达到了99.7%和99.9%. 上清液的紫外光谱图及染料分子中铜离子浓度的检测结果表明,染料通过吸附方式从废水中去除. 通过SEM, TEM观察发现,生长菌体在吸附过程中,菌丝发生肿胀膨大,细胞壁发生结构重组,厚度增加10~15倍. 细胞壁的结构变化是生长菌体吸附染料的重要机制,为染料吸附提供位点和进入细胞内部的通道.     

Unravelling the bottleneck of phosphonic acid anchoring groups aiming toward enhancing the stability and efficiency of mesoscopic solar cells

Novel near-infrared sensitizers with different anchoring groups aiming toward improved stability and efficiency of dye-sensitized solar cells were synthesized. Adsorption of these dyes on the mesoporous TiO₂ surface revealed the dye adsorption rate of –CH=CH–COOH (SQ-139)>–CH=C(CN)COOH (SQ-140)>–PO₃H₂ (SQ-143)>–CH=C(CN)PO₃H₂ (SQ-148)>–CH=C(CN)PO₃H–C₂H₅ (SQ-157)>–PO₃H–C₂H₅ (SQ-151)> –CH=CH–COOH(–PO₃H₂) (SQ-162). The binding strength of these dyes on mesoporous TiO₂ as investigated by dye desorption studies follows SQ-162>SQ-143>SQ-148>SQ-139≫SQ-157~SQ-151≫SQ-140 order. The acrylic acid anchoring group was demonstrated to be an optimum functional group owing to its fast dye adsorption rate and better binding strength on TiO₂ along with good photoconversion efficiency. Results of dye binding on TiO₂ surface demonstrated that SQ-162 bearing double anchoring groups of phosphonic and acrylic acid exhibited>550 times stronger binding as compared to dye SQ-140 having cyanoacrylic acid anchoring group. SQ-140 exhibited the best photovoltaic performance with photon harvesting mainly in the far-red to near-infrared wavelength region having short circuit current density, open-circuit voltage and fill factor of 14.28 mA·cm^–2, 0.64 V and 0.65, respectively, giving the power conversion efficiency of 5.95%. Thus, dye SQ-162 not only solved the problem of very poor efficiency of dye bearing only phosphonic acid while maintaining the extremely high binding strength opening the path for the design and development of novel near-infrared dyes with improved efficiency and stability by further increasing the π-conjugation.     

Biological treatment of effluent containing textile dyes

Colour removal of textile dyes from effluent was evaluated using a laboratory 'upflow anaerobic sludge blanket' reactor. Several commercial dyes were selected to study the effect of dye structure on colour removal. The anaerobic reactor was fed with glucose, an easily biodegradable organic matter and selected individual dyes. Results show that some of the dyes are readily reduced under anaerobic conditions even at a high concentration of 700 mg/l. The average removal efficiency for acid dyes using this method was between 80 and 90% and that observed for the direct dye used was 81%. Laboratory experiments using the anaerobic reactor with disperse dyes, such as an anthraquinonebased dye, were unsuccessful even at low concentrations of 35 mg/l. Additional experiments were conducted to evaluate the toxicity of a selected disperse dye to an anaerobic environment. Results indicate that the purified dye is more toxic to the biomass than the commercial one.