In situ IR spectroscopy during oxidation process of cobalt Prussian blue analogues
Hideharu Niwa1,2,3, Toshiaki Moriya4, Takayuki Shibata5
1Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 305-8571, Japan. niwa.hideharu.ga@u.tsukuba.ac.jp.
Abstract:
Cobalt Prussian blue analogues (Co-PBA; NaxCo[Fe(CN)6]y), consisting of cyano-bridged transition metal network, -Fe-CN-Co-NC-Fe-, are promising cathode materials for Na-ion secondary batteries. In the oxidation process, oxidization of Fe and/or Co are compensated by Na+ deintercalation. Here, we investigated the oxidization process of three Co-PBAs by means of in situ infrared absorption (IR) spectroscopy. With use of an empirical rule of the frequencies of the CN- stretching mode in ferrocyanide ([FeII(CN)6]4-) and ferricyanide ([FeIII(CN)6]3-), the oxidation processes of Co-PBAs were determined against the Fe concentration (y) and temperature (T). We will discuss the interrelation between the oxidation processes and Fe concentration (y).
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
UV–Vis Spectroscopy: Molecular Electronic Transitions
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is the extent of conjugation in...
Redox Titration: Other Oxidizing and Reducing Agents
Oxidation-Reduction Reactions
Oxidation of Alkenes: Syn Dihydroxylation with Potassium Permanganate


