The straightforward, efficient, solventless, RAPET (reactions under autogenic pressure at elevated temperature) approach was explored for the fabrication of core-shell nanomaterials. Carbon-encapsulated SnS and SnSe nanorods were synthesized by a one-step thermal decomposition of tetramethyltin in the presence of either S or Se powder in a closed reactor at 700 degrees C for 40 min, under their autogenic pressure in an inert atmosphere. The powder X-ray diffraction measurements provided structural evidence for the formation of pure orthorhombic phases of SnS or SnSe particles. The Raman spectroscopy measurements ensured that the nature of the coated carbon was semigraphitic. The scanning electron micrographs verified the 1D morphology of the formed SnS and SnSe chalcogenides, and their stoichiometry was confirmed by EDAX measurements. The HR-TEM micrographs distinguished between core and shell morphologies. The nitrogen gas adsorption on the surface of core-shell nanostructures was determined by BET surface area analysis. The plausible mechanism for the creation of chalcogenide cores (SnS or SnSe) with a carbon shell was elucidated.
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http://dx.doi.org/10.1021/la7040532 | DOI Listing |
ACS Nano
December 2024
Applied Physics Graduate Program and Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas 77005, United States.
Flash Joule heating has been used as a versatile solid-state synthesis method in the production of a wide range of products, including organic, inorganic, and ceramic products. Conventional flash Joule heating systems are large and customized, presenting significant barriers in the cost of assembly, the expertise needed to operate, and uniformity of results between different systems. Even laboratory-scale flash Joule heating systems struggle to operate above 10 g capacity, and they suffer from poor temperature controllability.
View Article and Find Full Text PDFHealth Aff Sch
November 2024
Health Equity Sciences, National Committee for Quality Assurance (NCQA), Washington, DC 20005, United States.
Quality measures for social determinants of health (SDOH) have been introduced or proposed in more than 20 federal programs, initiatives, or guidance documents to capture performance, but understanding the scope of work needed to effectively collect and align with these new measurement requirements is still in its early stages. The National Committee for Quality Assurance (NCQA) recently developed the Social Need Screening and Intervention (SNS-E) measure and is currently building 2 new domains of interest: utility insecurity and social connection. Before these domains can be leveraged to drive population health, the feasibility of collecting and reporting on them must be assessed.
View Article and Find Full Text PDFJ Am Chem Soc
November 2024
Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
Two-dimensional and layered van der Waals materials promise to overcome the limitations of conventional ferroelectrics in terms of miniaturization and material integration, but synthesis has produced only small (up to few micrometer-sized) ferroic crystals. Here, we report the realization of in-plane ferroelectric few-layer crystals of the monochalcogenides tin(II) sulfide and selenide (SnS, SnSe) whose linear dimensions exceed the current state of the art by up to 1 order of magnitude. Such large crystals allow the investigation of ferroic domain patterns that are unaffected by edges and finite-size effects.
View Article and Find Full Text PDFJ Phys Condens Matter
November 2024
School of Physics Science and Information Technology, Liaocheng University, Liaocheng 252000, People's Republic of China.
Over the past few decades, semiconductor materials of the group IV-VI monochalcogenides have attracted considerable interest from researchers due to their rich structural characteristics and excellent physical properties. Among them, GeS, GeSe, SnS, and SnSe crystallize in an orthorhombic structure () at ambient conditions. It has been reported that GeS, SnS, and SnSe transform into a higher symmetry orthorhombic structure () at high pressure, while the phase transformation route of GeSe at high pressure remains controversial.
View Article and Find Full Text PDFACS Nano
November 2024
Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
Emergent phenomena in traditional ferroelectrics are frequently observed at heterointerfaces. Accessing such functionalities in van der Waals ferroelectrics requires the formation of layered heterostructures, either vertically stacked (similar to oxide ferroelectrics) or laterally stitched (without equivalent in 3D-crystals). Here, we investigate lateral heterostructures of the ferroelectric van der Waals semiconductors SnSe and SnS.
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