Facile visualization of the initial nucleation and growth of an active metal electrodeposited in a high temperature molten salt using a detachable disk electrode

Abstract

In molten salt electrodeposition, a clear understanding of the initial nucleation and growth of nuclei formed on a substrate/electrode is critical to determining the morphology and structure of deposits in order to produce devices and products in various scientific fields. However, it is a challenge to obtain and characterize micro- or nano-sized nuclei, especially for very active elements due to their high sensitivity to water and oxygen. This problem is made even worse when the nuclei are accompanied by a larger amount of solid salts. In this work, we have designed a detachable disk electrode (DDE) which can prevent inessential salts from adhering to the disk substrate, greatly reducing the operational complexity, and ultimately enhancing the effectiveness and ease of visualizing initial nucleation. Uranium, a typical radioactive element with high metallic activity in the nuclear fuel cycle, was chosen as an example to test the sampling performance of the DDE. High-quality visualization of the initial nucleation and growth morphology of uranium on different substrates is presented here for the first time. The DDE provides a universal and simple scheme with wide applicability to the study of initial nucleation in high temperature molten salts, in fields such as electrodeposition, electrosynthesis, electroplating, etc.