Search for: All records

Abstract The structural integrity of atomically thin two-dimensional molybdenum disulfide (MoS₂) is crucial for high-temperature applications, including nanoelectronics and optoelectronics. This study explores the structural stability and electrical performance, under extended thermal exposure in air, of MoS₂flakes synthesized via chemical vapor deposition (CVD) and mechanical exfoliation. The MoS₂flakes, both CVD-grown and mechanically exfoliated, were subjected to heating at 200 °C with a relative humidity of 60(±5)% for a prolonged period and investigated with atomic force microscopy and Raman spectroscopy. This study shows that CVD-grown flakes developed noticeable cracks after prolonged heating, whereas mechanically exfoliated flakes mostly retained their structural integrity. Also, both types of flakes showed a decrease in layer thickness and lateral size over time, with mechanically exfoliated flakes exhibiting a comparatively smaller reduction in substrate coverage area. In addition, MoS₂-based two-terminal devices were subjected to heating at 150 °C for approximately 1100 h, and their electrical characterization revealed a steady rise in current during constant voltage (5 V) conditions. This study enhances our understanding of MoS₂stability and provides guidance for improving the reliability of MoS₂-based devices in high-temperature electronic applications. 

Zeolitic imidazolate framework-8 (ZIF-8) thin films of controlled thickness and area can be formed under a cathodic working electrode, showcasing a simple means of direct fabrication of thin metal–organic framework (MOF) films on various substrates. 

Anions play many roles in our environment. Consequently, the development of synthetic receptors capable of targeted anion binding is of ongoing importance. While many such receptors are known, simplified designs and measurement approaches are always beneficial. Herein, we report the synthesis of a non-symmetric aryl-triazole pentad receptor appended with a single ferrocene, its electrochemistry, and the selective binding to dihydrogen phosphate (H2PO4–) anions of its oxidized form over various environmentally prevalent anions (HSO4–, Cl–, NO3–). The receptor was constructed using a modular architecture with simple installation of a ferrocene unit using click chemistry. Electrochemical analysis on the receptor revealed that addition of H2PO4– anion led to a shift in the redox peaks of the receptor (FcP) towards more negative potentials, indicating higher anion affinity was achieved after the ferrocene was oxidized to its cationic form (FcP+). This work verifies prior studies on the efficacy of cationic charge in simpler receptor design for the creation of functional host-guest systems.