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Abstract: In this work, the underpotential deposition of metals such as copper and lead during the electrochemical deposition of gold is investigated to understand the influence that the incorporation of a second metal has on the morphology of gold nanostructures. The incorporation of Pb or Cu, even at concentrations as low as 0.2 %, significantly influences the morphology of the deposit, where the formation of elongated structures from a central gold structure is favored. These nanostructures are characterized by cyclic voltammetry, X‐ray diffraction, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy and are tested for their suitability as a sensing layer for the electrochemical detection of nitrite ions in aqueous solution. A limit of detection of 0.3 μM is achieved with a linear range up to 1 mM, which is adequate for the determination of nitrite contained within food products. [ABSTRACT FROM AUTHOR]

Closed WS2 nanoboxes were formed by topotactic sulfidization of a WO3/WO3·1/3H2O intergrowth precursor. Automated diffraction tomography was used to elucidate the growth mechanism of these unconventional hollow structures. By partial conversion and structural analysis of the products, each of them representing a snapshot of the reaction at a given point in time, the overall reaction can be broken down into a cascade of individual steps and each of them identified with a basic mechanism. During the initial step of sulfidization WO3·1/3H2O transforms into hexagonal WO3 whose surface allows for the epitaxial induction of WS2. The initially formed platelets of WS2 exhibit a preferred orientation with respect to the nanorod surface. In the final step individual layers of WS2 coalesce to form closed shells. In essence, a cascade of several topotactic reactions leads to epitactic induction and formation of closed rectangular hollow boxes made up from hexagonal layers. [ABSTRACT FROM AUTHOR]