Inherent Electrochemistry of Layered Post‐Transition Metal Halides: The Unexpected Effect of Potential Cycling of PbI 2

The development of two‐dimensional nanomaterials has expedited the growth of advanced technological applications. PbI 2 is a layered inorganic solid with important and unique properties suitable for applications in the detection of electromagnetic radiation. While the optical and electrical properties of layered PbI 2 have been generally established, its electrochemistry has remained largely unexplored. In this work, we examine the inherent electrochemistry of PbI 2 in relation to its morphological and structural properties. A direct comparison between commercially available and solution‐grown PbI 2 showed high similarity in properties based on characterizations by X‐ray photoelectron spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy. The respective layered PbI 2 materials also exhibited similar inherent electrochemistry. Electrochemical potential cycling of PbI 2 in phosphate buffer resulted in the dissolution of iodide ions from PbI 2 to form complex lead‐phosphate‐chloride with the oxygen groups of the phosphate ions while retaining the hexagonal structure. In the case of KCl solution, the formation of PbO 2 was observed.