通讯机构：
[Tang, Yiwen] C;Cent China Normal Univ, Inst Nanosci & Technol, Coll Phys & Technol, Wuhan 430079, Peoples R China.
关键词：
A. Microporous materials;B. Chemical synthesis;C. Electron microscopy
摘要：
In the present work, high surface area mesoporous cobalt oxide (Co3O4) nanobelts have been synthesized by thermal treatment of cobalt hydroxide carbonate (CHC) precursors. CHC nanobelts were prepared by a facile hydrothermal method. Control experiments with variations in reaction time, solvent and different cobalt source revealed that temperature and sulfates are key factors in determining the formation of CHC nanobelts. Scanning electron microscopy and transmission electron microscopy images showed that the Co3O4 nanobelts consisted of mesoporous nanobelts with the average width of 40 nm. Brunauer–Emmett–Teller (BET) gas adsorption measurement further indicated that the products presented a rather large surface area (172.09 m2 g−1).
作者机构：
[Tang, Yiwen; Wang, Bixiao; Chen, Xinqi; Heng, Bojun; Hu, Xiaoyan; Sun, Daming] Cent China Normal Univ, Inst Nanosci & Technol, Wuhan 430079, Peoples R China.;[Sun, Yongming; Zhou, Wei] Wuhan Jiawei Photovolta Lighting Co Ltd, Wuhan, Peoples R China.
通讯机构：
[Tang, Yiwen] C;Cent China Normal Univ, Inst Nanosci & Technol, Wuhan 430079, Peoples R China.
关键词：
Dye-sensitized solar cell;High internal surface area;Ultralong nanoporous
摘要：
Arrays of novel ultralong nanoporous ZnO nanobelts (NBs) are developed with a two-step synthesis strategy. This strategy combines two processes, a rapid hydrothermal synthesis of vertically aligned ultralong Zn(OH)F NB arrays directly on fluorine-doped tin oxide (FTO) at pH = 8.5 and conversion of a pyrolysis Zn(OH)F NB intermediate into nanoporous ZnO NB. Two factors play crucial roles in the rapid synthesis of ultralong Zn(OH)F nanobelt (NB) arrays, i.e., the pretreatment of the FTO substrate before entering the aqueous solution of Zn2+ (2 M) and the presence of excess F− in the hydrothermal reaction solution. Upon the subsequent pyrolysis of the Zn(OH)F precursor at 500 °C for 2 h, ultralong nanoporous ZnO NB arrays are successfully generated. In addition, every NB is composed of a large number of nanocrystals and nanopores, which exhibit preferred orientation. Dye-sensitized solar cells (DSSCs) based on the ultralong porous ZnO NB arrays are assembled, and a high conversion efficiency (η) of 3.28% for a 27 μm thick film is obtained at 0.9 suns. This can be attributed to the high internal surface area and pronounced light scattering, as well as a good electron collection efficiency comparable with that of ZnO nanorod (NR)-based DSSCs.
作者机构：
[Tang, Yiwen; Hu, Xiaoyan] Cent China Normal Univ, Inst Nanosci & Technol, Wuhan 430079, Hubei, Peoples R China.
会议名称：
4th International Conference on One-Dimensional Nanomaterials (ICON)
会议时间：
DEC 07-09, 2011
会议地点：
Beijing, PEOPLES R CHINA
会议主办单位：
[Hu, Xiaoyan;Tang, Yiwen] Cent China Normal Univ, Inst Nanosci & Technol, Wuhan 430079, Hubei, Peoples R China.
摘要：
A rainbow solar cell configuration based on CdS-CdSe quantum dots (QDs) orderly assembled onto ZnO nanowire (NW) was designed. The rainbow configuration involves alternate cycles of ZnO NW growth and orderly deposition of CdS and CdSe on the different ZnO layer. As a demonstration, in the assembly of ZnO NW bilayer, the presence of CdS shell on the first ZnO NW layer can effectively avoid the fusion of the first ZnO NW layer at the root. Thus the internal surface area of the bilayer assembly is largely enhanced. When the bilayer assemblies were used to fabricate quantum-dot-sensitized solar cells (QD-SSCs), a power conversion efficiency (eta) of 0.197% was obtained which was higher than that of conventional ZnO/CdS based QDSSCs. Such a rainbow QD-SSC allows one to couple high electron injection rate of QDs and wide absorption range effectively.
作者机构：
[Tang, Yiwen; Xiao, Ting; Li, Bihui; Luo, Lijuan; Hu, Xiaoyan] Cent China Normal Univ, Inst Nanosci & Technol, Wuhan 430079, Peoples R China.;[Lu, Lu; Wang, Jianbo] Wuhan Univ, Dept Phys, Wuhan 430072, Peoples R China.
通讯机构：
[Tang, Yiwen] C;Cent China Normal Univ, Inst Nanosci & Technol, Wuhan 430079, Peoples R China.
关键词：
DSSCs;Heterojunction;SnO 2;Zn 2 SnO 4
摘要：
Zn2SnO4–SnO2 heterojunction nanocomposites (ZTO–SnO2) with high mass amount of ZTO were synthesized by a two-step technique. The route involves firstly the synthesis of monodispersed ZnSn(OH)6 nanocubes with a 50–60 nm edge length as precursors by simple coprecipitation of Na2SnO3·3H2O and ZnCl2 aqueous solution, assisted by ultrasonic treatment and then followed by calcination of the precursors at 800 °C under N2 atmosphere. The as-synthesized nanoparticles were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Heterojunction between ZTO and SnO2 nanoparticle was confirmed by the electron energy loss spectroscopy (EELS) elemental mapping and high-resolution TEM (HRTEM). The photovoltaic performance of the ZTO–SnO2 based DSSC was examined by measuring the J-V curves both in dark and under illumination. The results show that the ZTO–SnO2 based DSSC exhibits superior photovoltaic performance as compared to the single phase ZTO based DSSCs. Under illumination of AM 1.5 simulated sunlight (100 mW/cm2), the open circuit voltage of the cell based on ZTO–SnO2 is 706 mV, the short-current density is 2.85 mA/cm2, and the efficiency is 1.29% which is increased by 43% from 0.90% to 1.29% compared with pure ZTO. The formation of the heterojunctions between ZTO and SnO2 nanoparticles is believed to reduce the recombination between injected electrons and redox I−/I3− and improve the performance of the DSSC.Graphical abstractResearch highlights▶ The ZTO–SnO2 based DSSC shows superior photovoltaic performance than single phase ZTO or Pm-ZTO–SnO2 (physical mixture of ZTO and SnO2 nanoparticles having the same ZTO/SnO2 composition) based DSSC. ▶ The obvious improvement in the photovoltaic performance is mainly ascribed to the efficient injected electrons transfer between the two materials via heterojunctions and consequent suppress the recombination.
作者机构：
[Yiwen Tang; Bihui Li; Gang Lü; Lijuan Luo] Institute of Nano-Science and Technology, Huazhong Normal University, Wuhan, Hubei, China
通讯机构：
[Bihui Li; Yiwen Tang] I;Institute of Nano-Science and Technology, Huazhong Normal University, Wuhan, Hubei, China<&wdkj&>Institute of Nano-Science and Technology, Huazhong Normal University, Wuhan, Hubei, China
关键词：
Core-shell;Dye-sensitized solar cell (DSSC);Electrode;TiO2@MgO
摘要：
In this study, TiO2@MgO core-shell film was obtained by using a simple chemical bath deposition method to coat a thin MgO film around TiO2 nanoparticles. The core-shell configuration was characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and high-resolution transmission electron microscopy (HRTEM). Lattice fringes were observed for the TiO2 particles, and the MgO shell showed an amorphous structure, revealing a clear distinction between the core and shell materials. Applying the core-shell film as photoanode to the dye-sensitized solar cells (DSSCs), it shows a superior performance compared to the pure TiO2 electrode. Under the illumination of simulated sunlight (75 mW·cm−2), the short circuit photocurrent (J
sc), the open circuit photovoltage (V
oc), and the fill factor (f
F) are 8.80 mA·cm−2, 646 mV, and 0.69, respectively, and the conversion efficiency (η) increased by 21.8% (from 4.32% to 5.26%) when dipping for optimum condition.
摘要：
High density aligned ZnO nanotube (NT) arrays were synthesized using a facile chemical etching of electrochemically deposited ZnO nanorods (NRs). The influence of etching time and solution concentration on the ZnO NT formation was investigated. Moreover, cadmium selenide (CdSe) nanoparticles as sensitizers were assembled onto the ZnO NT and NR arrays for solar cell application. A conversion efficiency (eta) of 0.94% was achieved for CdSe/ZnO NT-based solar cell under the white light illumination intensity of 85 mW/cm(2). An 8% enhancement in eta was observed between the CdSe/ZnO NT-based and NR-based solar cell due to the enhancement of the photocurrent density. ZnO NT arrays have been proved to have a superior ability as compared with ZnO NR arrays when employed as a semiconductor film. (c) 2010 Elsevier B.V. All rights reserved.
