Fixed Energy
X‑ray Absorption Voltammetry
- Publication date
- Publisher
Abstract
In this paper, the fixed energy X-ray
absorption voltammetry (FEXRAV) is introduced. FEXRAV represents a
novel in situ X-ray absorption technique for fast and easy preliminary
characterization of electrode materials and consists of recording
the absorption coefficient at a fixed energy while varying at will
the electrode potential. The energy is chosen close to an X-ray absorption
edge, in order to give the maximum contrast between different oxidation
states of an element. It follows that any shift from the original
oxidation state determines a variation of the absorption coefficient.
Although the information given by FEXRAV obviously does not supply
the detailed information of X-ray absorption near edge structure (XANES)
or extended X-ray absorption fine structure (EXAFS), it allows to
quickly map the oxidation states of the element under consideration
within the selected potential windows. This leads to the rapid screening
of several systems under different experimental conditions (e.g.,
nature of the electrolyte, potential window) and is preliminary to
more deep X-ray absorption spectroscopy (XAS) characterizations, like
XANES or EXAFS. In addition, the time-length of the experiment is
much shorter than a series of XAS spectra and opens the door to kinetic
analysis