Highly Porous Polypyrrole (PPy) Hydrogel Support for the Design of a Co-N-C Electrocatalyst for Oxygen Reduction Reaction.

Atomically dispersed metal-nitrogen-carbon (M-N-C) catalysts have emerged as one of the most promising platinum-group metal (PGM)-free cathode catalysts for oxygen reduction reaction (ORR). Among the various approaches to enhance the ORR performance of the catalysts, increasing the density of accessible active sites is of paramount importance. Thus, nitrogen-rich support with abundant porosity can be very propitious.

Sub-wavelength waveguide properties of 1D and surface-functionalized SnO nanostructures of various morphologies.

One-dimensional (1D) SnO sub-wavelength waveguides are a critical contribution to advanced optoelectronics. Further understanding of the surface defects and role of morphology in 1D SnO nanowires can help to better utilize these nanostructures more efficiently. For this purpose, three different nanowires (NWs), namely belts, cylindrical- and square-shaped structures were grown using SnO quantum dots as a precursor material.

Process-specific mechanisms of vertically oriented graphene growth in plasmas.

Applications of plasma-produced vertically oriented graphene nanosheets (VGNs) rely on their unique structure and morphology, which can be tuned by the process parameters to understand the growth mechanism. Here, we report on the effect of the key process parameters such as deposition temperature, discharge power and distance from plasma source to substrate on the catalyst-free growth of VGNs in microwave plasmas. A direct evidence for the initiation of vertical growth through nanoscale graphitic islands is obtained from the temperature-dependent growth rates where the activation energy is found to be as low as 0.

Engineering Silicon to Porous Silicon and Silicon Nanowires by Metal-Assisted Chemical Etching: Role of Ag Size and Electron-Scavenging Rate on Morphology Control and Mechanism.

We demonstrate controlled fabrication of porous Si (PS) and vertically aligned silicon nanowires array starting from bulk silicon wafer by simple chemical etching method, and the underlying mechanism of nanostructure formation is presented. Silicon-oxidation rate and the electron-scavenging rate from metal catalysis play a vital role in determining the morphology of Si nanostructures. The size of Ag catalyst is found to influence the Si oxidation rate.