A gravitational electrochemical cell for Operando grazing incidence X-ray absorption spectroscopy experiments on industrial materials

We present here a new design for an electrochemical cell that allows grazing incidence X-ray absorption spectroscopy (XAS) experiments to be performed. The idea is to have a laminar flow of electrolyte in front of the working electrode. In this way, the thickness of the electrolyte layer can be kept small enough to cope with the penetration depth of X-rays at the K-edges of 3d metals. The laminar flow is achieved by letting the electrolyte flow by gravity over a flat surface of the cell, where the working electrode is positioned. In this way, surface sensitivity can be achieved on bulk electrodes, as demonstrated by performing the water splitting reaction on nickel wires, which are the materials used in industrial conditions. The cell is easy to use and can be easily installed in an experimental hutch of an XAS beamline, the only requirement being to have enough space.