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酞菁与TiO2微粒间的光诱导电子转移相互作用 总被引:2,自引:0,他引:2
带有负电荷取代基的四磺化酞菁化合物与TiO2超微粒在溶液中通过静电相互吸引,能够形成基态复合物。通过吸收光谱和荧光光谱,计算了磺化酞菁与TiO2在溶液中的表现缔合平衡常数K.与相应的烷氧基取代酞菁化合物作比较,并通过单光子技术测定染料荧光寿命。结合荧光光谱,证明了磺化酞菁与TiO2在溶液中的缔合作用,有利于激发态酞菁染料向半导体TiO2的导带注入电子,从而发生分子间的电子转移反应,将磺化酞菁吸附在TiO2纳晶薄膜电极上,进行光电性能测试。结果表明,染料敏化TiO2纳晶薄膜电极光电响应的大小与染料在电极表面吸附的强弱有关。 相似文献
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在保持染料吸附量不变的条件下,通过增加TiO2薄膜厚度来降低染料在TiO2薄膜表面的吸附浓度.研究了染料吸附浓度与染料敏化太阳能电池(DSC)中界面电荷复合效应的关系.研究发现,在低染料吸附浓度下,DSCs中界面电荷复合效应明显降低,并由此使得DSC在薄膜厚度增加时,仍能保持0.72~0.80的高填充因子;在TiO2光电极有效面积由0.25 cm2增大到1 cm2时,总光电转换效率(η)损失由34.7%减少到19.6%. 相似文献
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应用光电化学方法研究了两种菁类染料Cy3和Cy5复合敏化TiO2纳米晶电极的光电化学行为.结合两种染料的紫外-可见光谱和循环伏安曲线,确定了Cy3和Cy5的电子基态和激发态能级位置.结果表明两种染料的激发态能级位置能与TiO2纳米粒子导带边位置相匹配,复合敏化可以显著提高TiO2纳米晶的光电流,使TiO2纳米晶电极吸收波长由紫外光区红移至可见光区和近红外区.复合敏化降低了染料Cy3 在电极吸附时的聚集程度,使其单色光的转换效率(IPCE)提高了169%,复合敏化电极总的光电转换效率η为2.09%,分别是Cy3和Cy5单独敏化时光电转换效率的2.069 和1.229倍. 相似文献
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应用光电化学方法研究了两种菁类染料Cy3和Cy5复合敏化TiO2纳米晶电极的光电化学行为. 结合两种染料的紫外-可见光谱和循环伏安曲线, 确定了Cy3和Cy5的电子基态和激发态能级位置. 结果表明两种染料的激发态能级位置能与TiO2纳米粒子导带边位置相匹配, 复合敏化可以显著提高TiO2纳米晶的光电流, 使TiO2纳米晶电极吸收波长由紫外光区红移至可见光区和近红外区. 复合敏化降低了染料Cy3在电极吸附时的聚集程度, 使其单色光的转换效率(IPCE)提高了169%, 复合敏化电极总的光电转换效率η为2.09%, 分别是Cy3和Cy5单独敏化时光电转换效率的2.069和1.229倍. 相似文献
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研究了Ho3+离子表面修饰对TiO2纳米晶电极光电性能的影响. TiO2表面氧化钬的存在一方面降低了染料和TiO2之间的电子注入速率, 而另一方面它也能够抑制电荷复合. 结果表明, 在TiO2纳米晶薄膜表面修饰一定厚度的Ho3+离子层, 在电极表面就形成了一个势垒, 能够有效抑制电极表面的电荷复合, 从而提高了染料敏化太阳能电池的光电压和光电转化效率. 在93.1 mW·cm-2白光照射下, TiO2/Ho-0.1 和TiO2/Ho-0.2(0.1 和0.2分别是修饰TiO2电极的Ho3+溶液的浓度, 单位是mol·L-1)两个电极的光电转化效率分别达到8.3%和7.6%, 与TiO2电极(7.2%)比较, 分别增大了15%和5%. 相似文献
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研究了磺化2,3-萘酞菁锌(Ⅱ)、钴(Ⅱ)在DMF(N,N-二甲基甲酰胺)、DMSO(二甲基亚砜)、乙醇、水等溶剂中的电子吸收光谱和荧光光谱.萘酞菁配合物的Q带与相应的酞菁配合物Q带相比,电子吸收光谱红移80~90nm,荧光光谱红移约100nm,荧光强度也显增加.在金属萘酞菁中引入磺酸基,配合物的电子吸收光谱Q带发生红移,但是影响不大、对于相同中心金属的配合物,改变溶剂的种类对配合物的电子吸收光谱的Q带影响较大.在金属萘酞菁环上引入一个磺酸基时,在相同溶剂中与无取代萘酞菁相比发生荧光光谱Q带红移,荧光强度增大.但在萘酞菁环上继续引入磺酸基时,荧光强度反而减少.磺化萘酞菁钴比磺化萘酞菁锌有较大的荧光强度.不同浓度下的电子吸收光谱和荧光光谱说明金属萘酞菁有集聚倾向、能形成基激缔合物. 相似文献
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Kathiravan A Chandramohan M Renganathan R Sekar S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,71(5):1783-1787
Chlorophyll has been extracted from cyanobacteria. The adsorption of chlorophyll on the surface of colloidal TiO(2) through electrostatic interaction was observed. The apparent association constant (K(app)) of chlorophyll-TiO(2) obtained from absorption spectra is 3.78x10(4)M(-1). The K(app) value of chlorophyll-TiO(2) as determined from fluorescence spectra is 1.81x10(4)M(-1), which matches well with that determined from the absorption spectra changes. These data indicate that there is an interaction between chlorophyll and colloidal TiO(2) nanoparticle surface. The dynamics of photoinduced electron transfer from chlorophyll to the conduction band of colloidal TiO(2) nanoparticle has been observed and the mechanism of electron transfer has been confirmed by the calculation of free energy change (DeltaG(et)) by applying Rehm-Weller equation as well as energy level diagram. Lifetime measurements gave the rate constant (k(et)) for electron injection from the excited state chlorophyll into the conduction band of TiO(2) is 4.2x10(8)s(-1). 相似文献
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Kathiravan A Renganathan R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(3):1080-1083
The adsorption of riboflavin on the surface of TiO(2) colloidal particles and the electron transfer process from its singlet excited state to the conduction band of TiO(2) were examined by absorption and fluorescence quenching measurements. The apparent association constants (K(app)) were determined. The quenching mechanism is discussed involving electron transfer from riboflavin to TiO(2). 相似文献
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Kathiravan A Anbazhagan V Asha Jhonsi M Renganathan R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(3):615-618
A stable colloidal TiO(2) has been prepared. The interaction of meso-tetrakis (4-sulfonatophenyl) porphyrin (TSPP) with colloidal TiO(2) was studied by absorption and fluorescence spectroscopy. Upon excitation of its absorption band, the fluorescence emission of TSPP was quenched by colloidal TiO(2). The bimolecular quenching rate constant (k(q)) is 1.78 x 10(11)M(-1)s(-1). The porphyrin can participate in the quenching process by injecting electrons from its excited states into the conduction band of TiO(2). The quenching mechanism is discussed on the basis of the quenching rate constant as well as the reduction potential of the colloidal TiO(2). Rehm-Weller equation was applied for the calculation of free energy change (DeltaG(et)). 相似文献
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ZnO/TiO2复合涂层电极的制备及其光电性能 总被引:1,自引:1,他引:0
以氧化铟锡导电玻璃为基材,采用电泳沉积法制备负载型ZnO/TiO2复合涂层,经450℃后续烧结处理后,采用XRD、SEM、EDX和UV-Vis DRS对ZnO/TiO2复合涂层进行表征;在pH=7.00的磷酸盐缓冲溶液中,分别测试ZnO/TiO2复合涂层电极在紫外灯和100 W白炽灯辐照下的电化学阻抗谱、Tafel极化曲线和循环伏安等电化学性质。结果表明:ZnO以200~300 nm晶粒分散于复合涂层中,质量百分比为0.74%;ZnO/TiO2复合涂层在可见光区有一定的吸收;在可见光辐照下ZnO/TiO2复合涂层电极具有较好的光电活性,并对水的分解具有较强的光电催化活性。 相似文献
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N. Sh. Lebedeva Yu. A. Gubarev E. S. Yurina A. I. Vyugin I. M. Lipatova 《Russian Journal of General Chemistry》2017,87(10):2327-2331
The interaction of chitosan with copper(II) and cobalt(II) tetrasulfophthalocyanines is studied by spectral methods. The main parameters of binding of chitosan to anionic metal phthalocyanines are determined by Scatchard analysis. It is found that the formation of the polymer complex is considerably contributed by donor?acceptor interactions between the coordinately unsaturated metal phthalocyanine and chitosan amino groups. Сhitosan reacts with a monomeric cobalt(II) tetrasulfophthalocyanine, whereas copper(II) tetrasulfophthalocyanine in its complex with chitosan remains in the dimeric state. The reaction centers responsible for the Cu(SO3H)4Pc)2–chitosan and Co(SO3H)4Pc–chitosan complexes are revealed by means of IR spectroscopy. 相似文献
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Jung HS Lee SW Kim JY Hong KS Lee YC Ko KH 《Journal of colloid and interface science》2004,279(2):479-483
TiO2 film for use as dye-sensitized solar cell was prepared using the TiO2 colloidal sols (unpeptized sol and peptized sol). The optical properties and photocurrent-voltage characteristics of the resultant films were investigated. The optical transmittance of TiO2 thin film prepared from the peptized colloidal sol was over 90%, while that of TiO2 film from the unpeptized sol was under 80%. The TiO2 photoelectrode prepared from the peptized colloidal sol showed low photoelectric conversion efficiency (eta), 1.30%, whereas the efficiency of photoelectrode from the unpeptized sol was 2.21%. The high optical transmittance and low conversion efficiency of TiO2 film from the peptized sol are discussed in terms of dense microstructure due to the drying nature of well-dispersed colloidal sol. 相似文献
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Shin JH Kang JH Jin WM Park JH Cho YS Moon JH 《Langmuir : the ACS journal of surfaces and colloids》2011,27(2):856-860
Engineering of TiO(2) electrode layers is critical to guaranteeing the photoconversion efficiency of dye-sensitized solar cells (DSSCs). Recently, a novel approach has been introduced for producing TiO(2) electrodes using the inverted structures of colloidal crystals. This paper describes a facile route to producing ordered macroporous electrodes from colloidal crystal templates for DSSCs. Using concentrated colloids dispersed in a volatile medium, the colloidal crystal templates were obtained within a few minutes, and the thickness of the template was easily controlled by changing the quantity of colloidal solution deposited. Here, the effects of the structural properties of the inverse opal TiO(2) electrodes on the photovoltaic parameters of DSSCs were investigated. The photovoltaic parameters were measured as a function of pore ordering and electrode film thickness. Moreover, DSSC applications that used either liquid or viscous polymer electrolyte solutions were investigated to reveal the effects of pore size on performance of an inverse opal TiO(2) electrode. 相似文献
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采用AFM、XRD和EDS等手段,对TiNi合金在空气中、400—800℃下形成的氧化膜组织结构进行了分析,并对TiNi合金表面原位热氧化膜的光电性能进行了研究.结果表明,TiNi合金在空气中氧化原位形成的氧化膜的结构主要为金红石型二氧化钛,不同温度下生长的氧化膜存在择优取向;随着氧化温度的升高,所制备的TiO2/TiNi电极的稳态光电流和开路光电压随氧化温度的升高先增大后减小,在700℃所制备的TiO2/TiNi电极的稳态光电流最大. 相似文献