RESUMEN
Control over material structure and morphology during electrodeposition is necessary for material synthesis and energy applications. One approach to guide crystallite formation is to take advantage of epitaxy on a current collector to facilitate crystallographic control. Single-layer graphene on metal foils can promote "remote epitaxy" during Cu and Zn electrodeposition, resulting in growth of metal that is crystallographically aligned to the substrate beneath graphene. However, the substrate-graphene-deposit interactions that allow for epitaxial electrodeposition are not well understood. Here, we investigate how different graphene layer thicknesses (monolayer, bilayer, trilayer, and graphite) influence the electrodeposition of Zn and Cu. Scanning transmission electron microscopy and electron backscatter diffraction are leveraged to understand metal morphology and structure, demonstrating that remote epitaxy occurs on mono- and bilayer graphene but not trilayer or thicker. Density functional theory (DFT) simulations reveal the spatial electronic interactions through thin graphene that promote remote epitaxy. This work advances our understanding of electrochemical remote epitaxy and provides strategies for improving control over electrodeposition.
RESUMEN
This review paper discusses the properties of nanomaterials, namely graphene, molybdenum disulfide, carbon nanotubes, and quantum dots for unique sensing applications. Based on the specific analyte to be detected and the functionalization techniques that are employed, some noteworthy sensors that have been developed are discussed. Further, biocompatible sensors fabricated from these materials capable of detecting specific chemical compounds are also highlighted for COVID-19 detection purposes, which can aid in efficient and reliable sensing as well as timely diagnosis.