染料敏化太阳电池CuAl2O4/TiO2光阳极制备及性能

采用柠檬酸法制备了尖晶石型纳米晶CuAl2O4,将其添加到P25(degussa,TiO2)中,制备成CuAl2O4/TiO2薄膜光阳极,并组装成染料敏化太阳电池(DSSC),对其光电性能进行表征。结果表明:CuAl2O4的加入,电池性能得到提高;当CuAl2O4含量为2%(质量分数)时,与纯TiO2薄膜光阳极相比,光电转化效率提高了39.1%。     

浸渍提拉法修饰阳极对DSSC性能的影响

首先采用浸渍提拉法在导电玻璃上涂TiO2溶胶膜并烧结,再用P25粉制备TiO2浆料涂敷在溶胶膜上烧结制备成DSSC光阳极.对光阳极的双层膜结构进行XRD、FESEM等表征分析,并对相应的DSSC测试电池性能.采用正交实验设计,考查溶胶提拉次数、P25涂敷层数、在溶胶中加入乙基纤维素(EC)的含量等3个因素对DSSC性能的影响.结果表明,溶胶提拉10次,P25涂敷一层,不加EC时,电池性能最佳;P25层数对开路电压有重大影响.     

ZnO—TiO2染料敏化太阳能电池的制备和性能

采用低温水溶液法制备ZnO纳米花,将其与TiO2纳米颗粒以不同的质量比混合制备成复合浆料,采用刮涂法涂敷在掺氟的SnOz透明导电玻璃（FTO）上制备ZnO纳米花-TiO2纳米颗粒复合薄膜光阳极,与Pt对电极和电解质组装成染料敏化太阳能电池（DSSC）。通过光伏性能和电化学阻抗谱测试分析,研究ZnO纳米花与TiO2纳米颗...     

NiCr_2O_4/TiO_2薄膜光阳极的制备及性能研究

采用柠檬酸法制备了尖晶石型NiCr2O4纳米晶,然后掺合到P25(degussa TiO2)中,制备成NiCr2O4/TiO2薄膜光阳极,并组装成染料敏化太阳电池(DSSC),对其光电性能进行表征。研究发现NiCr2O4/TiO2形成界面势,NiCr2O4的扩散形成电势分布,促使光生电子和空穴向相反方向迁移。当NiCr2O4含量为1%(质量分数)时,与纯TiO2薄膜光阳极相比,光电转化效率(η)提高了30.8%,电池单色光转化率(IPCE)提高了13%(500nm)。     

基于正交试验法TiO2纳米薄膜的制备及光电性能的研究

以商业TiO2纳米粉(P25)为原料,将其充分研磨得到胶体,用刮涂和热处理的方法在氟掺杂氧化锡导电玻璃基底上制备TiO2纳米多孔薄膜阳极,并组装成染料敏化太阳能电池(DSSC).对TiO2膜进行X射线衍射、扫描电镜表征分析,并对所制备的DSSC进行光电性能测试.采用正交实验设计优化制备TiO2胶体时乙酰丙酮、OP乳化剂、蒸馏水的量和研磨时间,并讨论其对DSSC性能的影响.用在最优参数下所得胶体制备的DSSC的光电转换效率最高,约为4.51％.     

鸭跖草色素敏化TiO_2纳米管太阳能电池的研究

以高度有序TiO2纳米管阵列作为光阳极,鸭跖草色素作为敏化剂制备了天然染料敏化太阳能电池。阳极氧化6h制备的TiO2纳米管作为电极的电池的光电转换效率约达0.52%,短路电流为1.53mA/cm2。比较不同管长TiO2纳米管阵列对电池的光电性能的影响。利用紫外-可见光光谱仪研究鸭跖草色素的光吸收性能。利用电化学阻抗谱分析电池的界面阻抗。研究表明适当提高TiO2纳米管长度可以有效提高天然染料敏化太阳能电池的光电性能。     

TiO2/SnO2纳米晶膜的制备及其电学性能研究

采用丝网印刷的方式制备了TiO2纳米晶薄膜,然后在其上采用浸泡的方式制备了SnO2纳米晶薄膜,形成TiO2/SnO2膜结构的光阳极并应用于染料敏化太阳能电池。用SEM对样品进行了结构形貌分析,用电化学工作站研究表征了SnO2的浸泡溶液浓度和浸泡时间对光阳极的调制改性作用。SEM分析表明在TiO2纳米晶薄膜表面生长的SnO2纳米晶薄膜晶粒比TiO2更加细小,电学性能研究表明TiO2薄膜经过0.4 mol/L SnO2溶液浸泡处理50 min能对TiO2薄膜的结构及性能起到很好的改善作用,电池的光电转化效率提高了约7%。     

二氧化钛有序纳米阵列染料敏化太阳能电池光阳极的研究进展

介绍了染料敏化太阳能电池(DSSC)的结构和基本原理,综述了近年来作为DSSC光阳极的TiO2纳米管、纳米线、纳米棒阵列的制备工艺进展,重点介绍了阳极氧化法制备纳米管和水热法制备纳米线和纳米棒.阐述了通过改进TiO2纳米管提高DSSC效率的几种途径,包括优化纳米管的尺寸、改善纳米管的输运性能、在透明基板上生长纳米管、对纳米管进行表面修饰等.最后展望了TiO2纳米阵列DSSC的研究方向.     

浆料组成对染料敏化多孔TiO2太阳能电池性能的影响

在TiO2粉体中加入不同量的聚乙二醇400、OP乳化剂和乙酰丙酮,经球磨得到TiO2浆料,采用丝网印刷的工艺方法在基底上制备了多孔TiO2薄膜阳极,组装成DSSC。采用SEM、XRD和电化学工作站进行了表征及测试;利用正交实验探讨了浆料中聚乙二醇400、OP乳化剂、乙酰丙酮的量和球磨时间对DSSC光电性能的影响。研究结果表明,浆料的最佳配方是聚乙二醇400为0.4mL、OP乳化剂为0.02mL、乙酰丙酮为0.6mL和球磨时间为4h,由此可使制备的DSSC光电转化效率(η)达到3.44%。     

TiO_2/SrTiO_3核壳结构光阳极制备及其光电化学性能

采用水热法在纳米多孔TiO2光阳极表面包覆一薄层SrTiO3,制得TiO2/SrTiO3核壳结构光阳极,并用X射线衍射、扫描电镜、能谱仪、透射电镜及紫外可见吸收光谱对其进行表征。探讨了水热反应时间对TiO2/SrTiO3光阳极组装的染料敏化太阳能电池(DSSCs)的光电化学性能的影响。结果表明:钙钛矿结构的SrTiO3包覆在纳米多孔TiO2光阳极的表面,形成TiO2为核SrTiO3为壳的光阳极;SrTiO3包覆的样品吸收边有红移;与TiO2光阳极相比,水热反应制备的TiO2/SrTiO3核壳结构光阳极组装的DSSC短路电流密度明显增加,5h时光电性能最优,短路电流密度为13.98mA/cm2,开路电压为0.74V,填充因子为0.45,全光转换效率为4.68%,提高了35.65%。     

Assembly of individual TiO2-C60/porphyrin hybrid nanoparticles for enhancement of photoconversion efficiency

Rational organization of porphyrin and C60 on the electrode surface in photovoltaic structures is essential to yield high quantum efficiency. In the present work, individual TiO2 nanoparticles were modified by introducing C60 and porphyrin units on the surface, and then electrophoretically deposited on an ITO/SnO2 electrode. The morphology of the photoactive layer on the electrode was significantly different from that of the layer produced as a result of separate deposition of C60 and porphyrin. The maximum incident photon to current efficiency of the resulting electrode approached 88% at 410 nm, which is the highest value among molecule-based photovoltaic cells reported to date. This indicates that molecular assembly of the C60 and porphyrin units on the individual nanoparticles through strong chemical attachment is a key factor in improving effective electron transfer between the photoactive units and the electrodes.     

Fabrication and characterization of photoelectrode thin films with different morphologies of TiO2 nanoparticles for dye-sensitized solar cells

This study deals with the fabrication of three different morphologies of TiO2 nanoparticles to fabricate two-layer photoelectrode thin film for dye-sensitized solar cells (DSSC). The four different TiO2 morphologies are titania nanotubes (Tnt), TiO2 nanoparticles (H220), TiO2 nanoparticle (SP) and commercial DP-25 nanoparticles (P-25). To prepare the thin films of the photoelectrodes, the first layer is coated by H220 TiO2 nanoparticles, and the second is coated by 3 kinds of materials optimally proportionally mixed - P25, SP and Tnt. The photoelectric conversion efficiency of DSSCs with photoelectrodes fabricated using H220 reached 6.31%. Finally, the TiO2 nanaomaterials with four different morphologies were used to prepare a two layer photoelectrode with the structure of H220/P25-Tnt-SP which was combined with a Pt counter electrode to assemble DSSCs. These DSSCs had photoelectric conversion efficiencies of as high as 7.47%.     

Effect of surface fluorination of TiO2 particles on photocatalitytic activity of a hybrid multilayer coating obtained by sol-gel method

A multilayer photoactive coating containing surface fluorinated TiO(2) nanoparticles and hybrid matrices by sol gel approach based on renewable chitosan was applied on poly(lactic acid) (PLA) film by a step wise spin-coating method. The upper photoactive layer contains nano-sized functionalized TiO(2) particles dispersed in a siloxane based matrix. For the purpose of improving TiO(2) dispersion at the air interface coating surface, TiO(2) nanoparticles were modified by silane coupling agent 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FTS) with fluoro-organic side chains. An additional hybrid material consisting of chitosan (CS) cross-linked with 3-glycidyloxypropyl trimethoxy silane (GOTMS) was applied as interlayer between the PLA substrate and the upper photoactive coating to increase the adhesion and reciprocal affinity. The multilayer TiO(2)/CS-GOTMS coatings on PLA films showed a thickness of ~4-6 μm and resulted highly transparent. Their structure was exhaustively characterized by SEM, optical microscope, UV-vis spectroscopy and contact angle measurements. The photocatalytic activity of the multilayer coatings were investigated using methyl orange (MeO) as a target pollutant; the results showed that PLA films coated with surface fluorinated particles exhibit higher activity than films with neat particles, because of a better dispersion of TiO(2) particles. The mechanical properties of PLA and films coated with fluorinated particles, irradiated by UV light were also investigated; the results showed that the degradation of PLA substrate was markedly suppressed because of the UV adsorptive action of the multilayer coating.     

Fabrication and properties of meso-macroporous electrodes screen-printed from mesoporous titania nanoparticles for dye-sensitized solar cells

A meso-macroporous TiO₂ film electrode was fabricated by using mesoporous TiO₂ (m-TiO₂) nanoparticles through a screen-printing technique in order to efficiently control the main fabrication step of dye-sensitized solar cells (DSSCs). The qualities of the screen-printed m-TiO₂ films were characterized by means of spectroscopy, electron microscopy, nitrogen adsorption–desorption and photoelectrochemical measurements. Under the optimal paste composition and printing conditions, the DSSC based on the meso-macroporous m-TiO₂ film electrode exhibits an energy conversion efficiency of 4.14%, which is improved by 1.70% in comparison with DSSC made with commercially available nonporous TiO₂ nanoparticles (P25, Degussa) electrode printed with a similar paste composition. The meso-macroporous structure within the m-TiO₂ film is of great benefit to the dye adsorption, light absorption and the electrolyte transportation, and then to the improvement of the overall energy conversion efficiency of DSSC.     

An electrochemical glucose sensor from an organically modified nanocomposite of viologen and TiO2

An organically modified TiO2 nanocomposite was explored for glucose detection. Bis-Butyl viologen (BBV) was mixed with TiO2 nanoparticles to generate highly dispersed nanocomposite solution, which provided organically modified nanocomposite film of TiO2 (BBV-TiO2). A transistor type sensor was fabricated using the BBV-TiO2 film and platinum gate electrode. The BBV-TiO2 nanocomposite sensor showed higher sensitivity to glucose sensing in low concentration region compared to that of TiO2 sensor. This result was ascribed to facilitated electron transport by the adsorbed viologen molecules on TiO2 nanoparticles, where viologen molecules act as an electron transfer mediator between enzyme and TiO2.     

CeO2修饰的透明TiO2纳米管电极的电致变色器件

采用电化学沉积法在阳极氧化制备的TiO2纳米管阵列管壁上沉积一层CeO2纳米颗粒,再将CeO2修饰的透明TiO2纳米管阵列薄膜对电极与聚三甲基噻吩变色电极组装成透过型电致变色器件.实验结果表明:CeO2修饰的TiO2纳米管阵列薄膜仍保持良好的光透过性,其电荷存储能力比纯TiO2纳米管电极提高了30%.经CeO2修饰的TiO2纳米管改善了器件的性能,与对电极为单一TiO2纳米管阵列的器件相比,其对比度仍保持在38%左右,其褪色时间由1.3 s缩短为0.8 s.电致变色器件快速响应得益于纳米管与纳米颗粒组成的复合结构的高比表面积和快速的电荷传输过程.     

Near-infrared responsive PbS-sensitized photovoltaic photodetectors fabricated by the spin-assisted successive ionic layer adsorption and reaction method

A PbS-sensitized photovoltaic photodetector responsive to near-infrared (NIR) light was fabricated by depositing monolayered PbS nanoparticles on a mesoporous TiO(2) (mp-TiO(2)) film via the spin-assisted successive ionic layer adsorption and reaction (SILAR) method. By adjusting the size and morphology of the PbS nanoparticles through repeated spin-assisted SILAR cycles, the PbS-sensitized photovoltaic photodetector achieved an external quantum efficiency of 9.3% at 1140 nm wavelength and could process signals up to 1 kHz.     

Properties of dye-sensitized solar cells with TiO2 passivating layers prepared by electron-beam evaporation

The aim of this work is to prevent back transfer of electrons due to direct contact between the electrolyte and the FTO glass substrate using a TiO2 passivating layer. The TiO2 passivating layer was deposited on FTO glass by e-beam evaporation. The TiO2 film was prepared with different deposition rates. The specific surface area was reduced with increasing deposition rate. The nanoporous TiO2 upper layer was coated by screen-printing on the TiO2 passivating layer prepared by e-beam evaporation. The optical transmittance and absorbance of the TiO2 films depend on the morphology of the TiO2 passivating layer. The dye-sensitized solar cells influenced the surface morphology of the TiO2 passivating layer. The dye-sensitized solar cell using the TiO2 passivating layer recorded a maximum conversion efficiency of 4.93% due to effective prevention of the electron recombination to the electrolyte.     

Highly active nanocrystalline TiO(2) photoelectrodes

A simple method for the fabrication of highly photoactive nanocrystalline two-layer TiO(2) electrodes for solar cell applications is presented. Diluted titanium acetylacetonate has been used as a precursor for covering SnO(2):F (FTO) films with dense packed TiO(2) nanocrystallites. The nanoporous thick TiO(2) film follows the dense packed thin TiO(2) film as a second layer. For the latter, amorphous TiO(2) nanoparticles have been successfully synthesized by a sol-gel technique in an acidic environment with pH<1 and hydrothermal growth at a temperature of 200?°C. The acidic nanoparticle gel was neutralized by basic ammonia and a TiO(2) gel of pH?5 was obtained; this pH value is higher than the recently reported value of 3.1 (Park et al 2005 Adv. Mater. 17 2349-53). Highly interconnected, nanoporous, transparent and active TiO(2) films have been fabricated from the pH?5 gel. SEM, AFM and XRD analyses have been carried out for investigation of the crystal structure and the size of nanoparticles as well as the surface morphology of the films. Investigation of the photocurrent-voltage characteristics has shown improvement in cell performance along with the modification of the surface morphology, depending on pH of the TiO(2) gel. Increasing the pH of the gel from 2.1 to 5 enhanced the overall conversion efficiency of the dye-sensitized solar cells by approximately 30%. An energy conversion efficiency of 8.83% has been achieved for the cell (AM1.5, 100 mWcm(-2) simulated sunlight) compared to 6.61% efficiency in the absence of ammonia in the TiO(2) gel.     

Transparent nanostructured coatings with UV-shielding and superhydrophobicity properties

Visible light transparent, UV-shielding and superhydrophobic nanostructured coatings have been successfully fabricated through a facile layer-by-layer deposition of TiO(2) and SiO(2) nanoparticles. The coatings are composed of an underlying UV-shielding TiO(2) layer and a top fully covered protective SiO(2) layer. The resulting coatings can block 100% of UVB and UVC and almost 85% of UVA. The fabricated surfaces have contact angles exceeding 165° after coating with organic PTES (1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane) molecules. The transparent superhydrophobic surfaces exhibit extremely strong UV stability. All coatings retain the initial UV-shielding and superhydrophobic properties even after exposure to 275 nm UV light with a light intensity of 75 mW cm(-2) for 12 h.