A mild template-free aqueous route was successfully established to synthesize well-aligned ZnO nanorod arrays, which were proved to exhibit high optical property by PL spectra.

Single-walled carbon nanotube (SWCNTs) is a promising material candidate for fabricating highperformance electrodes in electrochemical capacitors. An intriguing question is what are the key material characteristics of SWCNTs that influence the performance of SWCNT-based capacitors? We grafted SWCNTs with different amounts of carboxylic groups by a surfactant free method. Their density was quantified using a fluorescence labeling method, ranging from 7.3 to 353.2 nmol m À2 . SWCNTs were also characterized by scanning electron microscope, N 2 physisorption, ultraviolet-visible-near-infrared absorption, Fourier transform infrared, Raman, and X-ray photoelectron spectroscopy. Functionalized SWCNTs show a minor increase in their microspores and mesopores volume, and the total surface area stays $322.8 m 2 g À1 . We correlated SWCNT physiochemical properties with the performance of assembled twoelectrode SWCNT capacitors. The specific capacitance, power density and energy density increase with increasing carboxylic group density, reaching the maximum at 146.1 F g À1 , 308.8 kW kg À1 and 13.0 Wh kg À1 at the density of $250-350 nmol m À2 . Potentiostatic electrochemical impedance spectroscopy analysis reveals that introducing an appropriate concentration of carboxylic groups plays two key roles: (1) it decreases the surface resistivity of SWCNT films, thus significantly reducing the equivalent series resistances of capacitors and (2) it enhances the surface wettability of SWCNTs, which not only offers more accessible sites for the physisorption of free electrolyte ions on SWCNT surfaces, but also increases ionic conductivity at electrode-electrolyte interfaces. These results and analysis provide a fundamental understanding of the effect of functionalization on the performance of SWCNT-based electrochemical capacitors, and shed light on a pathway by which electrochemical capacitors can be further improved for practical applications.

Bi 2 S 3 nanowire/CdS nanoparticle heterostructure has been designed and constructed through an easy wetchemistry approach at 140 °C for 8 h. The product is mainly composed of Bi 2 S 3 nanowires, several hundred nanometers long and 10 nm wide, and epitaxially grown triangle-like CdS nanoparticles with size of 20 nm at their surfaces. A possible sequential deposition growth mechanism is proposed on the basis of experimental results to reveal the formation of the nanoscale heterostructure. Under the irradiation of UV light, the as-prepared nanoscale Bi 2 S 3 /CdS heterostructure exhibits enhanced photochemical efficiency that can be mainly attributed to the microstructure of the product. In the nanoscale heterostructure, the CdS nanoparticle not only determines the overall band gap energy, but also controls the charge carrier transition, recombination, and separation, while the Bi 2 S 3 nanowire serves as support for the CdS nanoparticle, defines the specific surface area of the product and thus influences the photocatalytic activity. The effects of reaction parameters on the structure and photocatalytic activity of the final product are also discussed.

A large number of one‐dimensional bundles of ZnSe nanowires with diameters ranging from 15–20 nm and lengths of up to tens of micrometers have been prepared via the thermal treatment of a ribbon‐like precursor (ZnSe·3ethylenediamine), which has been synthesized by a mixed solvothermal route, in an argon atmosphere. The as‐obtained precursor has been characterized by powder X‐ray diffraction (XRD), transmission electron microscopy (TEM), IR spectroscopy, thermogravimetric analysis, and elemental analysis. XRD and high‐resolution TEM characterization reveal that the as‐synthesized ZnSe nanowires have the single‐crystal hexagonal wurtzite structure with the [001] growth direction. The surface chemical composition of ZnSe nanowires has been studied by X‐ray photoelectron spectroscopy. The cooperative action of the mixed solvents may be responsible for the formation of the morphology of the resulting products. Room‐temperature photoluminescence measurements indicate the as‐grown ZnSe nanostructures have a strong emission peak centered at 587 nm and two weak emission peaks centered at 435 and 462 nm. The strong emission from the ZnSe nanostructures reveals their potential as building blocks for optoelectronic devices.