Abstract
The intercalation of cations into electrodeposited nickel hexacyanoferrate (NiHCF) depends on the stoichiometry and oxidation state of the material. To better understand this material's performance as a cation separation matrix, the oxidation state needs to be measured independently from the stoichiometry, regardless of the particular intercalated cation. Reported is the use of Raman spectroscopy to quantify the absolute oxidation state of NiHCF thin films. Raman spectroscopy probes NiHCF's cyanide bonds, which are sensitive to the oxidation state of the matrix. The oxidation state is controlled via potentiostatic experiments in electrolytes containing Na<sup>+</sup>, K<sup>+</sup>, and Cs<sup>+</sup> (NO<sub>3</sub><sup>-</sup> is the common anion). Principal component analysis (PCA) on the Raman spectra shows that more than 90% of the spectral variance is captured by one principal component, with a score value shown to be directly related to the oxidation state of the film. A universal, predictive regression model was developed using these score values as the dependent variables and Raman spectra as the independent variables. The results were confirmed with electrochemistry and energy dispersive X-ray spectroscopy.
PDF Article
More Like This
Cited By
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
Contact your librarian or system administrator
or
Login to access Optica Member Subscription