In Situ X-Ray Techniques for Electrochemical Interfaces.

This article reviews progress in the study of materials using X-ray-based techniques from an electrochemistry perspective. We focus on in situ/in operando surface X-ray scattering, X-ray absorption spectroscopy, and the combination of both methods. The background of these techniques together with key concepts is introduced. Key examples of in situ and in operando investigation of liquid-solid and liquid-liquid interfaces are presented. X-ray scattering and spectroscopy have helped to develop an understanding of the underlying atomic and molecular processes associated with electrocatalysis, electrodeposition, and battery materials. We highlight recent developments, including resonant surface diffraction and time-resolved studies.

Resistive Switching in Electrodeposited Prussian Blue Layers.

Prussian blue (PB) layers were electrodeposited for the fabrication of Au/PB/Ag stacks to study the resistive switching effect. The PB layers were characterized by different techniques to prove the homogeneity, composition, and structure. Electrical measurements confirmed the bipolar switching behavior with at least 3 orders of magnitude in current and the effect persisting for the 200 cycles tested. The low resistance state follows the ohmic conduction with an activation energy of 0.2 eV.

Morphology and Structure of Electrodeposited Prussian Blue and Prussian White Thin Films.

The compound Prussian Blue (PB), and its reduced form Prussian White (PW) are nowadays considered, in applied and fundamental research groups, as potential materials for sustainable energy storage devices. In this work, these compounds were prepared by potentiostatic electrochemical synthesis, by using different deposition voltages and thicknesses. Thick, compact and uniform layers were characterized by scanning electron microscopy, X-ray diffraction, and Raman spectroscopy. Results have shown a well-defined transition voltage for growing Prussian Blue phases and a strong dependence of the morphology/growing orientation of the samples as a function of applied potential and thickness. For the negative potential tested of -0.10 V vs. SCE, a mixture of cubic and rhombohedral phases was observed.