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A Pt counter electrode of dye-sensitized solar cells (DSSCs) was prepared by a simple and low-cost pulse electrodeposition method. The catalytic activity and the Pt utilization efficiency of Pt films were investigated. In this study, four Pt counter electrodes were prepared by pulse electrodeposition at high current density on FTO substrates. The catalytic activity of the counter electrode and DSSC performance were optimized by varying the pulse electrodepositing cycles. The relationships between Pt nanostructure, electrochemical properties, interfacial charge transfer resistance and photovoltaic performance are investigated in detail. The Pt film prepared by 25 pulse electrodepositing cycles shows well-distributed Pt nanoparticles on the FTO substrate, which provides not only a larger electrochemical active surface area but also lower charge transfer resistance than others. The photovoltaic performance proves that the Pt counter electrode prepared by 25 pulse electrodepositing cycles at 30 mA/cm current density achieves the highest energy conversion efficiency of 8.45% among these samples. [ABSTRACT FROM AUTHOR]

Abstract: ZnO nanowires, nanorods and nanoparticles through modulating the ratio of water to methanol have been synthesized by using a mild and simple solution method. The as-prepared ZnO nanostructures have been characterized by atomic force microscopy and X-ray photoelectron spectroscopy. With the increase of the ratio of water to methanol, the morphology of ZnO nanostructures varied form denser nanowires, to sparse nanowires, to nanorods, and then to nanoparticles. The ratio of water to methanol is supposed to play an important role in the formation of ZnO nanostructures. The mechanism of formation is related to the chemical potential, which is simply proportional to their surface ratio. [Copyright &y& Elsevier]

Scanning probe lithography (SPL), employing the tip of an atomic force microscope to mechanically pattern various materials in nanoscale region has provided a simple but significant method for making nanostructures. We use this technique for the lithography of several kinds of substrate surfaces. The tip performance has been found to be a crucial factor in the lithographic process. Four types of cantilevers are employed in nanolithography, including standard silicon nitride (DNP), tapping mode™ etched silicon (TESP(W)), uncoated silicon cantilever (NSC21/50) and conductive platinum/iridium-coated probe. Results demonstrate that tips with smaller spring constants can not be used for physically scribing and nanomanipulating in our experiment. The possible mechanism of our experiment is discussed. [Copyright &y& Elsevier]

Abstract: In this paper, TiO2 hollow nanostructures with anatase walls have been rapidly fabricated by using CuO as template and microwave heating. These TiO2 hollow nanostructures have been characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Experimental results showed that the TiO2 shell transformed from amorphous to anatase phase in 3min, induced by the hot CuO core under microwave irradiation. The diameter of TiO2 hollow nanostructures is about 50–80nm, and the length is about 200–300nm. The thickness of the shell is about 3nm. This method is promising to be used to synthesize other nanomaterials with a hollow nanostructure. [Copyright &y& Elsevier]

Abstract: Circular nanoscale structures of inorganic salt, MgCl2, are constructed by extended plasmid DNA pBR322 as a template on mica substrates, and these nanosized structures of 6.2±1.3 to 8.2±1.8 nm in height, and 1.35±0.18 to 2.93±0.25 μm in length are investigated by atomic force microscopy (AFM). The chemical element components of these nanostructures are characterized by XPS. We also discuss a possible formation mechanism of these circle nanostructures. [Copyright &y& Elsevier]