Shewanella-mediated biosynthesis of manganese oxide micro-/nanocubes as efficient electrocatalysts for the oxygen reduction reaction.

Developing efficient electrocatalysts for the oxygen reduction reaction (ORR) is critical for promoting the widespread application of fuel cells and metal-air batteries. Here, we develop a biological low-cost, ecofriendly method for the synthesis of Mn2 O3 micro-/nanocubes by calcination of MnCO3 precursors in an oxygen atmosphere. Microcubic MnCO3 precursors with an edge length of 2.

Biomolecule-doped PEDOT with three-dimensional nanostructures as efficient catalyst for oxygen reduction reaction.

Metal macro-cyclic compounds have drawn considerable attention as alternative catalysts for oxygen reduction reaction. However, the continuous pyrolysis process usually needed for improving the performance of these compounds require an elevated temperature and complicated procedures, thus leading to an unpredictable transformation of the chemical structures and limiting their applications. Herein, we develop a new insight to fabricating hemin-doped poly (3,4-ethylenedioxythiophene) (PEDOT) with controllable three-dimensional nanostructures via a one-step, tri-phase, self-assembled polymerization routine.

Electrochemically fabricated polypyrrole-cobalt-oxygen coordination complex as high-performance lithium-storage materials.

Current lithium-ion battery (LIB) technologies are all based on inorganic electrode materials, though organic materials have been used as electrodes for years. Disadvantages such as limited thermal stability and low specific capacity hinder their applications. On the other hand, the transition metal oxides that provide high lithium-storage capacity by way of electrochemical conversion reaction suffer from poor cycling stability.

Polyaniline microtubes with a hexagonal cross-section and pH-sensitive fluorescence properties.

Polyaniline (PANI) microtubes with a hexagonal cross-section are successfully synthesized by a self-assembly process in the presence of 8-hydroxyquinoline-5-sulfonic acid (HQS) as a dopant and FeCl(3) as an oxidant. The wall thickness of the PANI/HQS microtubes can be adjusted by the content of the oxidant. It is proposed that the aniline/HQS salts serve as a hard template for the formation of the hexagonal-cross-section microtubes.

Fe2(SO4)3 as a binary oxidant and dopant to thin polyaniline nanowires with high conductivity.

This article exposes a facial approach to self-assemble polyaniline (PANI) nanowires with thin diameter (approximately 10 nm) and high room-temperature conductivity (approximately 10(0) S/cm) by using Fe(2)(SO(4))(3) as a binary oxidant and dopant. The new method not only saves hard templates and postprocess of template removal but also simplifies the reagent. Formation yield, diameter, and room-temperature conductivity of the nanowires are affected by the molar ratios of Fe(2)(SO(4))(3) to aniline.

A versatile approach to the fabrication of palladium hollow spheres with aluminiumoxide nanoparticles as template.

Palladium hollow nanospheres were prepared by the adsorption of metal nanoparticles onto functionalized gamma-Al2O3 templates. The silanizing agent 3-mercaptopropyl trimethoxysilane was reacted with the surface of the gamma-Al2O3 templates to afford thiol-terminal groups. Metal layers of palladium were coated directly on the gamma-Al2O3 templates by increasing the temperature stepwise.

Conducting polymer nanostructures and their application in biosensors.

Nowadays, functionalized conducting polymer nanomaterials have been received great attention in nanoscience and nanotechnology because of their large surface area. This article reviews various methods for synthesis of conducting polymer nanostructures and their applications in sensing materials, focusing on hard-template, soft-template and other methods and the formation mechanism of conducting polymer nanostructures by these methods. Conducting polymer nanostructures, such as nanotubes, nanowires, and nanoparticles, as sensing platforms for various applications are also summarized.

Some issues related to polyaniline micro-/nanostructures.

This feature article reviews the authors' work combined with highlighted specific aspects of polyaniline (PANI) macro/nanostructures, focusing on such issues as the following. 1) The new development of a hard-template method. 2) Evaluation of a template-free method in universality, controllability, and simplicity as well as the self-assembly mechanism.

Electromagnetic functionalized cage-like polyaniline composite nanostructures.

Novel cage-like and electromagnetic functional polyaniline (PANI)/CoFe2O4 composite nanostructures, in which the self-assembled PANI nanofibers (approximately 15 nm in diameter) entwined around the octahedral CoFe2O4 magnet acting as the nucleation site or template, were successfully prepared by FeCl3 as either oxidant and dopant via a self-assembly process. The coordination effect of the magnet as a nucleation site or template and the magnetic interaction between the PANI nanofibers and CoFe2O4 as a driving force results in such cage-like nanostructures. The cage-like composite nanostructures not only have high conductivity (sigmamax approximately 5.

Magnetic properties of conducting polymer nanostructures.

Magnetic susceptibility measurements on conducting polyaniline and polypyrrole nanostructures with different dopant type and doping level as functions of temperature and magnetic field are reported. The susceptibility data cannot be simply described as Curie-like susceptibility at lower temperatures and temperature-independent Pauli-like susceptibility at higher temperatures; some unusual transitions are observed in the temperature dependence of susceptibility, for example, paramagnetic susceptibility decreases gradually with lowering temperature, which suggests the coexistence of polarons and spinless bipolarons and possible formation of bipolarons with changing temperature or doping level. In particular, it is found that the direct current magnetic susceptibilities are strongly dependent on applied magnetic field, dopant type, and doping level.

Electromagnetic functionalized and core-shell micro/nanostructured polypyrrole composites.

Core-shell micro/nanostructured and electromagnetic functionalized polypyrrole (PPy) composites were prepared by a self-assembly process associated with the template method in the presence of p-toluenesulfonate acid (p-TSA) as the dopant, in which the spherical hydroxyl iron (Fe[OH], 0.5-5 microm in diameter) functioned not only as the hard template, but also as the "core" of the micro/nanostructure, and the self-assembled PPy-p-TSA nanofibers (20-30 nm in diameter) acted as the "shell" (50-100 nm in thickness) of the microspheres. We found that the core-shell micro/nanostructures exhibit controllable electromagnetic properties by adjusting the mass ratio of Fe[OH] to pyrrole monomer.

Property influence of polyanilines on photovoltaic behaviors of dye-sensitized solar cells.

The influence of polyanilines (PANIs) as hole conductors on the photovoltaic behaviors of dye-sensitized solar cells is studied. The current-voltage (I-V) characteristics and the incident photon to current conversion efficiency (IPCE) curves of the devices are determined as the function of different conductivities and morphologies of PANIs. The results show that the conductivity of PANIs affects the performance of the devices greatly, and PANI with the intermediate conductivity value (3.