Co-presence of PtNi nanowires and ionic liquid in carbon mesopores enhances electrocatalytic oxygen reduction activity.

The electrocatalytic activity of PtNi nanowires is enhanced by the co-presence of ionic liquid in carbon mesopores. Three-dimensional transmission electron microscopy tomography and surface-enhanced infrared absorption spectroscopy confirm the co-presence of PtNi nanowires and ionic liquid inside carbon mesopores even under electrochemical conditions.

Detecting dynamic responses of materials and devices under an alternating electric potential by phase-locked transmission electron microscopy.

An apparatus is developed for transmission electron microscopy (TEM) to acquire image and spectral data, such as TEM images, electron holograms, and electron energy loss spectra, synchronized with the measurement of the dynamic response of a specimen under an applied alternating current (AC) electric potential (voltage, denoted V). From a V of frequency f, a shutter pulse signal is generated to open and close a pre-specimen shutter in a base TEM apparatus. A pulse is generated per V cycle from the targeted phase Φ to Φ +∆Φ with phase width ∆Φ (∆Φ <2π).

Electron beam induced etching of carbon nanotubes enhanced by secondary electrons in oxygen.

Multi-walled carbon nanotubes (CNTs) are subjected to electron-beam-induced etching (EBIE) in oxygen. The EBIE process is observed in situ by environmental transmission electron microscopy. The partial pressure of oxygen (10 and 100 Pa), energy of the primary electrons (80 and 200 keV), and environment of the CNTs (suspended or supported on a silicon nitride membrane) are investigated as factors affecting the etching rate.