Advanced TexSy-C Nanocomposites for High-Performance Lithium Ion Batteries.

This study is dedicated to expand the family of lithium-tellurium sulfide batteries, which have been recognized as a promising choice for future energy storage systems. Herein, a novel electrochemical method has been applied to engineer micro-nano TexSy material, and it is found that TexSy phases combined with multi-walled carbon nanotubes endow the as-constructed lithium-ion batteries excellent cycling stability and high rate performance. In the process of material synthesis, the sulfur was successfully embedded into the tellurium matrix, which improved the overall capacity performance. TexSy was characterized and verified as a micro-nano-structured material with less Te and more S. Compared with the original pure Te particles, the capacity is greatly improved, and the volume expansion change is effectively inhibited. After the assembly of Li-TexSy battery, the stable electrical contact and rapid transport capacity of lithium ions, as well as significant electrochemical performance are verified.

Work function measurement for Ag-TCNQ (TCNQ = tetracyanoquinodimethane) nanowires.

The Ag-TCNQ (TCNQ = tetracyanoquinodimethane) nanowires synthesized by a vapor transport reaction exhibit promising field emission properties. Their effective work function at high applied electric field was estimated to be about 1.70 eV according to the Fowler-Nordheim (F-N) theory. In this work, we directly measured the intrinsic work function of Ag-TCNQ nanowires via the ultraviolet photoemission spectroscopy (UPS). According to the threshold binding energy, the work function is obtained to be 5.45 eV, which shows a large discrepancy with the preivous estimation based on F-N theory. The reductive effecitive work function during the field emission is mainly attributed to the morphology-induced enhancement of the nanowire array.

Facile synthesis of V-shaped copolymer brushes grafted onto the surface of graphene oxide via coupling reactions.

Mid-functionalized ABC triblock copolymers with a short central B block were synthesized via the RAFT process, and further used as well-defined V-shaped copolymers to graft onto graphene oxide by coupling reactions.

On the morphology, structure and field emission properties of silver-tetracyanoquinodimethane nanostructures.

Silver-tetracyanoquinodimethane(Ag-TCNQ) nanostructured arrays with different morphologies were grown by an organic vapor-transport reaction under different conditions. The field emission properties of nanostructured arrays were studied systematically. Their morphology and crystal structure were characterized by SEM and XRD, respectively. It was found that the field emission properties were strongly dependent on the reaction temperature and the initial Ag film thickness. The lowest turn-on field with 10-nm-thick silver film is about 2.0 V/µm, comparable to that of carbon nanotubes. The film crystal structure and the morphology are contributed to the final emission performance.

Synthesis and electrical properties of ZnO nanowires.

Vertically aligned ZnO nanowires were synthesized on the p(+) silicon chip by modifying the CVD process with a vapor trapping design. Scanning electron microscopy was used to investigate the morphology of as-obtained nanowires. X-ray diffraction showed that the obtained nanowires were ZnO crystalline. The rectifying characteristics of the p-n heterojunction composed of ZnO nanowires and a p(+) silicon chip were observed. The positive turn-on voltage was 0.5V and the reverse saturation current was 0.01mA. These vertically aligned ZnO nanowires showed a low field emission threshold of 4V/microm at a current density of 0.1microA/cm(2). The dependence of emission current density on the electric field followed Fowler-Nordheim relationship.

Morphology investigation of Ag(TCNQ) synthesized by the vapor-transport reaction method.

Ag(TCNQ) nanostructures with wire-, belt- and flower-like morphologies have been prepared on Si wafers by a vapor-transport reaction between silver and TCNQ without additional catalyst. The morphologies were characterized by SEM and optical microscopy. The composition of nanowires was tested by Raman spectroscopy. The growth mechanism of different morphologies based on the VS mechanism is emphasized.

Scanning electron microscopy investigation of Cu-TCNQ micro/nanostructures synthesized via vapor-induced reaction method.

Micro/nanostructures based on the metal-organic complex Cu-TCNQ were successfully synthesized by a novel method: vapor-induced reaction. Scanning electron microscopy was used to investigate the morphology on the three different parts of the substrate: the hot reaction area, a transitional reaction area and an induced reaction area. The results show that the morphology of the as-grown structures evolves from microstructures to nanostructures. The formation mechanism of these different structures may be understood from electrochemical principles and the decreasing concentration of TCNQ.

Microscopy investigation of Ag-TCNQ micro/nanostructures synthesized via two solution routes.

The micro/nanostructures of metal-organic complex Ag-TCNQ were successfully synthesized by the reaction between Ag film and TCNQ dissolved in acetonitrile via two solution routes, i.e. immerging and dipping reaction. X-ray diffraction confirmed that the obtained Ag-TCNQ micro/nanostructures were crystalline. The morphology of the as-grown structures varied from straight nanowires and microtubes to complex fractals and dendrites. The growth mechanism of the mainly dendrites may be considered within the framework of DLA model.