Sodium is globally available, which makes a sodium-ion rechargeable battery preferable to a lithium-ion battery for large-scale storage of electrical energy, provided a host cathode for Na can be found that provides the necessary capacity, voltage, and cycle life at the prescribed charge/discharge rate. Low-cost hexacyanometallates are promising cathodes because of their ease of synthesis and rigid open framework that enables fast Na+ insertion and extraction. Here we report an intriguing effect of interstitial H2O on the structure and electrochemical properties of sodium manganese(II) hexacyanoferrates(II) with the nominal composition Na2MnFe(CN)6·zH2O (Na2−δMnHFC). The newly discovered dehydrated Na2−δMnHFC phase exhibits superior electrochemical performance compared to other reported Na-ion cathode materials; it delivers at 3.5 V a reversible capacity of 150 mAh g–1 in a sodium half cell and 140 mAh g–1 in a full cell with a hard-carbon anode. At a charge/discharge rate of 20 C, the half-cell capacity ...

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Removal of interstitial H2O in hexacyanometallates for a superior cathode of a sodium-ion battery.

Spectroelectrochemical study of polypyrrole films

Microplastic in the surface waters of the Ross Sea (Antarctica): Occurrence, distribution and characterization by FTIR.

Numerical error analysis of derivative spectrometry for the quantitative analysis of mixtures

A Simulator for Cyclic Voltammetric Responses

Interfacial oxidation and reduction of Prussian Blue (PB), KFeIII[FeII(CN)6]·nH2O (n ≈ 10), powder were probed in situ with Fourier transform infrared attenuated total reflection (FT-IR/ATR) spectroscopy. The combination of electrochemistry in the absence of liquid electrolyte with internal reflectance FT-IR spectroscopy was accomplished using a simple two-electrode sandwich-type cell in which a crystalline germanium served both as a working electrode and an infrared transparent element. Application of sufficiently large potential differences to sandwich electrodes led to oxidation and reduction of PB at opposing interfaces. The spectra, which were monitored by difference, clearly show changes in the cyanide stretching frequency range upon oxidation and reduction.

http://nathan.instras.com/MyDocsDB/doc-594.pdf

In Situ FT-IR/ATR Spectroelectrochemistry of Prussian Blue in the Solid State

The kinetics and mechanism for the oxidation of o-tolidine have been studied at both platinum and optically transparent electrodes Spectral data show that the intermediate is a dimeric species Evaluation of fast kinetic rates for homogeneous reactions following charge transfer is demonstrated using transparent electrode

Kinetic and mechanism studies of o-tolidine electro-oxidation using optically transparent electrodes

Direct log ratio recording, rapid scanning spectrophotometer

Spectrochemical-electrochemical evaluation of kinetics using optically transparent electrodes

A laboratory rapid scanning spectrophotometer employing an oscillating mirror for wavelength scanning was modified to provide wavelength modulation for derivative spectrophotometry. The modulation resulted from the superimposition of a small sinusoidal waveform on the main driving triangular waveform for the oscillating mirror. The higher frequency of wavelength modulation attainable in the spectrophotometer effectively eliminated the processing of any lower frequency noise. The results of wavelength modulation and correlation spectrophotometry using a new optical design based on a Czerny-Turner monochromator system and applied to the analysis of low levels of sulfur dioxide is presented. The approach of derivative and correlation spectrophotometry is applicable to the sensitive and selective analysis of low concentrations of substances having spectral fine structures.

Jerzy W. Strojek

Papers

In Situ FT-IR/ATR Spectroelectrochemistry of Prussian Blue in the Solid State

Kinetic and mechanism studies of o-tolidine electro-oxidation using optically transparent electrodes

Direct log ratio recording, rapid scanning spectrophotometer

Spectrochemical-electrochemical evaluation of kinetics using optically transparent electrodes

Derivative spectrophotometry. Application to trace sulfur dioxide analysis