共查询到20条相似文献,搜索用时 15 毫秒
1.
Sun Lae Kim Song-Rim Jang R. Vittal Jiwon Lee Kang-Jin Kim 《Journal of Applied Electrochemistry》2006,36(12):1433-1439
The beneficial influence of incorporation of acid-treated and rutile TiO2 (r-TiO2)-modified multi-wall carbon nanotubes (MWNTs) in TiO2 films on photocurrent–voltage characteristics of dye-sensitized solar cells (DSSCs) was studied. Two different routes were adopted for the modification of acid-treated MWNTs (a-MWNTs) with r-TiO2. The films and MWNTs were characterized by electron microscopy, energy dispersive X-ray spectroscopy, XRD and Raman spectroscopy. In the case of incorporation of a-MWNTs with r-TiO2 modification, short-circuit photocurrent (J
sc) of the pertinent DSSC increased by 35% compared with that of a cell with bare TiO2 film. The open-circuit voltage remained almost the same for all cases. The enhanced J
sc is explained by the increased surface area of the film, enhanced cluster formation of TiO2 particles around a-MWNTs, and improved interconnectivity of TiO2 particles in the presence of a-MWNTs. 相似文献
2.
Yi‐Jhen Wu Liang Chao Ko‐Shan Ho Ying‐Jie Huang Yu‐Lan Huang Chi‐Shiang Yang Bo‐Hao Tseng 《应用聚合物科学杂志》2012,124(6):5270-5278
A multiwalled carbon nanotubes (MWCNTs) were carboxylated after refluxing with sulfuric and nitric acids. These attached carboxylic acid groups were further condensated with o‐phenylene diamine into amide catalyzed by dicyclohexyl carbodiimide (DCC). The obtained amidized MWCNTs were in situ‐polymerized with aniline monomers to graft a conducting polyaniline (PANI) onto MWCNT (ES‐g‐MWCNTs) through the polymerization occurring in the ortho‐ and meta‐positions. The reduced conductivity of the MWCNT after carboxylation can be recovered after grafting with PANI, which owns a strong λmax at the near infrared region due to the extended conjugation from MWCNTs to PANI. Transmission electronic microscopic pictures show a gradual broadening of the MWCNT diameter after carboxylation, amidization, and polymerization. The weight loss from the thermogravimetric thermograms due to the carboxylations of MWCNTs, amidized MWCNTs, and the PANI grafted MWCNTs into CO2 can be used to estimate the degree of carboxylation, amidization, and grafting of PANI. The degree of carboxylation of MWCNT calculated from ESCA spectrum is around 23% close to that estimated from TGA thermogram. The doping level of redoped PANI‐grafted MWCNT is found to be 27.78% much less than the maximum 50% of neat PANI. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
3.
4.
Electrodeposition of nanoporous ZnO films and their applications to dye-sensitized solar cells (DSSCs) were investigated in the aim of developing cost-effective alternative synthetic methods and improving the ZnO-based DSSCs performance. ZnO films were grown by cathodic electrodeposition from an aqueous zinc nitrate solution containing polyvinylpyrrolidone (PVP) surfactant. PVP concentration had strong effects on the grain sizes and surface morphologies of ZnO films. Nanoporous ZnO film with grain size of 20-40 nm was obtained in the electrolyte containing 4 g/L PVP. The X-ray diffraction pattern showed that nanoporous ZnO films had a hexagonal wurtzite structure. Optical properties of such films were studied and the results indicated that the films had a band gap of 3.3 eV. DSSCs were fabricated from nanoporous ZnO films and the cell performance could be greatly improved with the increase of ZnO film thickness. The highest solar-to-electric energy conversion efficiency of 5.08% was obtained by using the electrodeposited double-layer ZnO films (8 μm thick nanoporous ZnO films on a 200 nm thick compact nanocrystalline ZnO film). The performance of such cell surpassed levels attained in previous studies on ZnO film-based DSSCs and was among the highest for DSSCs containing electrodeposited film components. 相似文献
5.
Yaoming Xiao Jihuai Wu Gentian Yue Jianmin Lin Miaoliang Huang Zhang Lan 《Electrochimica acta》2011,(24):621
A platinum/single-wall carbon nanotube (Pt/SWCNT) film was sprayed onto a flexible indium-doped tin oxide coated polyethylene naphthalate (ITO/PEN) substrate to form a counter electrode for use in a flexible dye-sensitized solar cell using a vacuum thermal decomposition method at low temperature (120 °C). The obtained Pt/SWCNT electrode showed good chemical stability and light transmittance and had lower charge transfer resistance and higher electrocatalytic activity for the I3−/I− redox reaction compared to the flexible Pt electrode or a commercial Pt/Ti electrode. The light-to-electric energy conversion efficiency of the flexible DSSC based on the Pt/SWCNT/ITO/PEN counter electrode and the TiO2/Ti photoanode reached 5.96% under irradiation with a simulated solar light intensity of 100 mW cm−2. The efficiency was increased by 25.74% compared to the flexible DSSC with an unmodified Pt counter electrode. 相似文献
6.
ABSTRACT: Composite made of multiwalled carbon nanotubes coated with silver was fabricated by an electroless deposition process. The thickness of silver layer is about 40 to 60 nm, characterized as nano-crystalline with (111) crystal orientation along the nanotube's axial direction. The characterization of silver/carbon nanotube [Ag/CNT] nanowire has shown the large current carrying capability, and the electric conductivity is similar to the pure silver nanowires that Ag/CNT would be promising as building blocks for integrated circuits.PACS: 81.05.uj, carbon nanotubes, carbon-based materials, diamond/nanocarbon composites. 相似文献
7.
对电极作为染料敏化太阳能电池(dye-sensitized solar cell,DSSC)的重要组成部分,对电极材料性能的好坏直接影响着染料敏化太阳能电池的光电转化效率。最常使用的对电极电催化材料是贵金属铂,而铂十分稀少而且价格昂贵,并且铂很容易被碘电解液腐蚀,不利于染料敏化太阳能电池的产业化发展。本文重点综述了2010年以来染料敏化太阳能电池非铂对电极的研究成果,简要说明了对电极在染料敏化太阳能电池中的作用,详细介绍了非铂金属、碳材料、导电聚合物和无机化合物等对电极材料,分析了各类非铂对电极材料的特点、制备工艺、发展前景、优缺点和改进措施。最后提出,继续开发各种成本低、原料易得以及稳定高效的新型非金属对电极材料仍是今后染料敏化太阳能电池研究的一个重要方向。 相似文献
8.
In recent times, there is an increasing need for effective control of electromagnetic pollution, which can avoid excessive radiation effects on the human body. Microwave absorption materials are attracting wide research interests to reduce electromagnetic pollution due to the rapid development of electronic equipment. In this study, Nitrile butadiene rubber (NBR)/ethylene propylene diene monomer rubber (EPDM) were mixed with multiwalled carbon nanotubes (MWCNT) to prepare microwave absorbing materials. The distribution of fillers, AC conductivity, complex permittivity, and microwave absorption performance of the composites were systematically investigated. It found that the AC conductivity, both real and imaginary parts of the permittivity were significantly improved in the composite with the increasing ratio of MWCNT contents. The NBR/EPDM/MWCNT composites with eight parts per hundred concerning with rubber (phr) MWCNT had a minimum reflection loss (RLmin) of −48.1 dB at the optimum thickness of 2.07 mm. Importantly, the adding sequence of MWCNT and plasticizer dioctyl phthalate (DOP) to the rubber matrix is found to play an important role in determining the distribution of fillers and the structure of polymer blends. The composite with plasticizer added before MWCNT exhibited a better impedance matching and as a result, achieved a good microwave absorption performance. 相似文献
9.
Holographic polymer‐dispersed liquid crystal (HPDLC) films were fabricated with varying amounts of multiwalled carbon nanotubes (MWCNTs) to optimize the electro‐optical performance of the HPDLC films. The MWCNTs were well dispersed in the prepolymer mixture up to 0.5 wt%, implying that polyurethane acrylate (PUA) oligomer chains wrap the MWCNTs along their length, resulting in high diffraction efficiency and good phase separation. The hardness and elastic modulus of the polymer matrix were enhanced with increasing amounts of MWCNTs because of the reinforcement effect of the MWCNTs with intrinsically good mechanical properties. The increased elasticity of the PUA matrix and the immiscibility between the matrix and the liquid crystals (LCs) gradually increased the diffraction efficiency of the HPDLC films. However, the diffraction efficiency of HPDLC films with more than 0.05 wt% MWCNTs was reduced, caused by poor phase separation between the matrix and LCs because of the high viscosity of the reactive mixture. HPDLC films showing a low driving voltage (<3 V µm?1), a fast response time (<10 ms) and a high diffraction efficiency (>75%) could be obtained with 0.05 wt% MWCNTs at 40 wt% LCs. Copyright © 2010 Society of Chemical Industry 相似文献
10.
In this work, the morphology of ZnO materials could be controlled by changing the capping agent at constant alkali solution in hydrothermal process. ZnO nanomaterials with the structure of flowers, sheet-spheres and plates were obtained with the capping agent of ammonia, citric acid and oxalic acid, respectively. Thus prepared ZnO nanomaterials were characterized and applied as the photo-anode materials for dye-sensitized solar cell. All synthesized ZnO nanomaterials possessed high crystalline wurtzite structures grown in the (0 0 1) direction with the size of 2-4 μm, which consist of ZnO units around 20-400 nm. Among them, Sheet-sphere ZnO showed the highest crystallinity, surface area and uniform film morphology, resulting in the significantly improved PV performance with the overall conversion efficiency of 2.61% in dye-sensitized solar cell (DSSC) fabricated with sheet-sphere ZnO. It is notable that the ZnO materials with sphere structure may be the optimal photo-anode material among various ZnO nanomaterials for DSSC. 相似文献
11.
The nano-hollow spherical ZnO (NHS ZnO) photoelectrodes were prepared using functionalized polystyrene nanoparticles with flexible dimensional control of the particle diameter for dye-sensitized solar cells applications. NHS ZnO was formed by ZnO nanoparticles that accumulated on the surface of functionalized polystyrene with a high ionic strength. This method represents a one-step preparation method for an inorganic shell via polymerization between ZnO complexes. Even though NHS ZnO has a submicron size, it composed of nanoparticles that connect with each other, thereby implying good electron transfer properties, and has a high surface area. The submicron-sized diameter NHS ZnO has an enhanced light scattering capacity, which promotes the photons with more opportunities to be absorbed by the N719 dye molecules. Therefore, the ZnO films prepared from 600 nm to 1000 nm NHS ZnO possessed higher IPCE values over a wide range (from 400 nm to 750 nm) compared to films of the 300 nm ZnO due to the enhanced light scattering capacities of the film. In photocurrent-voltage measurements, the short-circuit current density of 300 nm and 600 nm NHS ZnO increases from 3.33 mA/cm2 to 6.53 mA/cm2 while the cell efficiency increases from 1.04% to 3.02% due to the light scattering efficiency. Electrochemical impedance spectroscopy showed that electrons in NHS ZnO with a larger particle size have a longer electron lifetime than NHS ZnO with a smaller particle size, as the latter hinders the electron transport in the NHS ZnO nanostructured films. 相似文献
12.
Jie Deng Yan-zhen Zheng Qian Hou Jian-Feng Chen Weilie Zhou Xia Tao 《Electrochimica acta》2011,(11):4176
A novel solid-state hierarchically structured ZnO dye-sensitized solar cell (DSC) was assembled by using TiO2 as filler in polyethylene oxide (PEO)/polyethylene glycol (PEG) electrolytes and ZnO nanocrystalline aggregates as photoanode film. Under optimized composite polyelectrolyte containing PEO/oligo-PEG/TiO2/LiI/I2 the photovoltaic performance of the solid-state ZnO DSCs was significantly better, with an overall conversion efficiency (η) of 1.8% under irradiation of 100 mW/cm2, which was higher than those of the cells with PEO/TiO2/LiI/I2 (η = 1.1%) or PEO/oligo-PEG/LiI/I2 electrolyte (η = 1.5%). Further, the hierarchically structured ZnO-based cell showed a higher η value of 2.0% under 60 mW/cm2 radiation. The morphologies, ionic conductivity of three different composite electrolytes and their performance to the DSCs were also studied by FESEM, I–V data, IPCE and EIS. 相似文献
13.
《国际智能与纳米材料杂志》2013,4(2):92-100
A convenient approach to fabricate metal (i.e. gold, platinum, and palladium) nanoparticles on highly dispersed pristine carbon nanotubes (CNTs) was developed using a conjugated block copolymer of poly(3-hexylthiophene)-b-poly(vinylpyrrolidone) (P3HT-b-PVP). P3HT-b-PVP not only provides a stable dispersion of pristine CNTs through the π–π interactions between P3HT block and CNTs, but also introduces PVP groups on CNT surfaces to induce the heterogeneous nucleation of metal nanoparticles and protect them from aggregating. The density of metal nanoparticles on CNT surfaces was controlled by the metal salt/CNT feed ratio. The simple processing procedure, versatility in synthesizing various metal nanoparticles, high metal nanoparticle loading capacity, and excellent dispersibility and processability of the product make this approach a promising method to fabricate metal nanoparticles on CNTs. 相似文献
14.
Teen-Hang Meen Yi-Ting Jhuo Shi-Mian Chao Nung-Yi Lin Liang-Wen Ji Jenn-Kai Tsai Tien-Chuan Wu Wen-Ray Chen Walter Water Chien-Jung Huang 《Nanoscale research letters》2012,7(1):579
In this study, we used the electrochemical anodization to prepare TiO2 nanotube arrays and applied them on the photoelectrode of dye-sensitized solar cells. In the field emission scanning electron microscopy analysis, the lengths of TiO2 nanotube arrays prepared by electrochemical anodization can be obtained with approximately 10 to 30 μm. After titanium tetrachloride (TiCl4) treatment, the walls of TiO2 nanotubes were coated with TiO2 nanoparticles. XRD patterns showed that the oxygen-annealed TiO2 nanotubes have a better anatase phase. The conversion efficiency with different lengths of TiO2 nanotube photoelectrodes is 3.21%, 4.35%, and 4.34% with 10, 20, and 30 μm, respectively. After TiCl4 treatment, the efficiency of TiO2 nanotube photoelectrode for dye-sensitized solar cell can be improved up to 6.58%. In the analysis of electrochemical impedance spectroscopy, the value of Rk (charge transfer resistance related to recombination of electrons) decreases from 26.1 to 17.4 Ω when TiO2 nanotubes were treated with TiCl4. These results indicate that TiO2 nanotubes treated with TiCl4 can increase the surface area of TiO2 nanotubes, resulting in the increase of dye adsorption and have great help for the increase of the conversion efficiency of DSSCs. 相似文献
15.
染料敏化太阳电池(dye-sensitized solar cell,DSC)的光阳极作为其重要的组成部分,在近些年的研究中取得了较大的进展。常用作光阳极的氧化物包括TiO2、ZnO、SnO2、Nb2O5、A12O3等,其中,TiO2因为综合性能表现突出,成为主要研究的光阳极材料。特别是TiO2纳晶薄膜的性质、形貌、结构等均会对DSC光电性能产生较大影响,其性质调节主要通过表面处理、修饰、掺杂等手段,而不同形貌纳米TiO2的研究主要表现在一维结构上,如纳米线、纳米棒等,本文就这些方面的研究情况进行简单归纳总结,分析影响电池性能的关键因素,并对如何更全面、更深入的提高DSC光电性能作简要展望。 相似文献
16.
In this work, we analyzed tensile properties of polypropylene‐multiwalled carbon nonotubes composite fibers. The multiwalled carbon nanotubes (MWCNTS) were used in different contents of 0, 1, 2, 3, 4, and 5 wt %. Dispersing agents were used to disperse MWCNTs in polypropylene matrix. After the dispersing agent was removed, the mixture was melt mixed. The fibers were spun by a home‐made melt spinning equipment and stretching was done at a draw ratio of 7.5. By using 1–5 wt % of MWCNTs, the modulus of composite fibers increased by 69–84% and tensile strength increased about 39% when compared with the virgin polypropylene fibers. In addition, the MWCNTs dispersion in the matrix was monitored by scanning electron microscopy and transmission electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
17.
18.
Mesut Ekmekci Cagatay Ela Sule Erten-Ela 《International Journal of Applied Ceramic Technology》2019,16(2):727-734
In this work, aluminum-doped ZnO (AZO, Al:ZnO) nanocomposite materials were prepared by a simple hydrothermal method using the microwave oven. Zinc oxide nanostructures were doped with aluminum in different dopant concentrations (0.5%, 1.0%, 1.5% and 2.0%). AZO materials were analyzed using XRD, SEM and EDX measurements. Also dye-sensitized solar cell (DSSC) performances of AZOs were investigated. The scanning electron microscopy (SEM) analysis confirms that the synthesized AZO nanomaterials were nanorods and nanoplates in shape and have 200 nm to 974 nm sizes in length and 116.1-269.5 nm in diameters (shown Figure 4-5). Dye-sensitized solar cell efficiencies are higher in 0.5% and 1% AZO nanorod materials. We have found the maximum efficiency as 1.94% for 1% doped AZO nanorod materials. 相似文献
19.
This paper reports, for the first time, a very rapid and large-scale synthesis and dye-sensitized solar cells (DSSCs) application of well-crystallized hexagonal-shaped ZnO nanorods at very low temperature of about 70 °C in 20 min. The thin films of as-grown nanorods were used as photo-anode materials to fabricate the DSSCs which exhibited an overall light to electricity conversion efficiency (ECE) of 1.86% with a fill factor of 74.4%, short-circuit current of 3.41 mA/cm2 and open-circuit voltage of 0.73 V. 相似文献
20.
A water soluble chitosan derivative (p‐chitosan) was synthesized and used to functionalize multiwalled carbon nanotubes (MWCNTs) through the noncovalent interaction. The interaction of p‐chitosan with MWCNTs was investigated by analyzing the spectra of ultraviolet‐visible, Fourier transform infrared, Raman, and X‐ray photoelectron. Circular dichroism spectroscopy was used to study the interaction as well. The results of the circular dichroism spectra indicate that, the interaction of p‐chitosan with MWCNT makes p‐chitosan less regularly structured. It was found that the interaction of p‐chitosan with MWCNTs at a lower temperature is stronger than that at a higher temperature; pH conditions affect the interaction between p‐chitosan and MWCNTs. © 2011 American Institute of Chemical Engineers AIChE J, 2012 相似文献