Isolated, atomically thin conducting membranes of graphite, called graphene, have recently been the subject of intense research with the hope that practical applications in fields ranging from electronics to energy science will emerge. The atomic thinness, stability and electrical sensitivity of graphene motivated us to investigate the potential use of graphene membranes and graphene nanopores to characterize single molecules of DNA in ionic solution. Here we show that when immersed in an ionic solution, a layer of graphene becomes a new electrochemical structure that we call a trans-electrode. The trans-electrode's unique properties are the consequence of the atomic-scale proximity of its two opposing liquid-solid interfaces together with graphene's well known in-plane conductivity. We show that several trans-electrode properties are revealed by ionic conductance measurements on a graphene membrane that separates two aqueous ionic solutions. Although our membranes are only one to two atomic layers thick, we find they are remarkable ionic insulators with a very small stable conductance that depends on the ion species in solution. Electrical measurements on graphene membranes in which a single nanopore has been drilled show that the membrane's effective insulating thickness is less than one nanometre. This small effective thickness makes graphene an ideal substrate for very high resolution, high throughput nanopore-based single-molecule detectors. The sensitivity of graphene's in-plane electronic conductivity to its immediate surface environment and trans-membrane solution potentials will offer new insights into atomic surface processes and sensor development opportunities.
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http://dx.doi.org/10.1038/nature09379 | DOI Listing |
ACS Nano
January 2025
Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea.
Bismuth oxyselenide (BiOSe) stands as a highly promising layered semiconductor with outstanding optical, electrical, and thermal properties. For the practical application of the material toward the devices, growing BiOSe directly on the amorphous substrate at low temperatures (<400 °C) is essential; however, the negatively charged bottom Se layer originating from alternating stacks of Se and [BiO] has hindered this process. In this work, we report the method for synthesizing a BiOSe film on amorphous alumina (AlO) directly at 350 °C by using chemical solution deposition.
View Article and Find Full Text PDFJ Mol Model
January 2025
Department of Chemistry, Federal Institute of Education, Science and Technology of Espírito Santo, Av. Min. Salgado Filho, Vila Velha, 29106-010, Espírito Santo, Brazil.
Context: This study presents quantum chemical analysis of 14 distinct carbon-based nanostructures (CBN), ranging from simple molecules, like benzene, to more complex structures, such as coronene, which serves as an exemplary graphene-like model. The investigation focuses on elucidating the relationships between molecular orbital (MO) energies, the energy band gaps, electron occupation numbers (eON), electronic conduction, and the compound topologies, seeking to find the one that approaches most of a graphene-like structure for in silico studies. Through detailed examination of molecular properties including chemical hardness and chemical potential, we demonstrate that the electronic exchange between orbitals is directly influenced by the structural topology of the carbon-based nanostructures, as the electron occupation numbers and the molecular orbital energies.
View Article and Find Full Text PDFJ Mol Model
January 2025
College of Chemical Engineering, Fuzhou University, Fuzhou, 350116, People's Republic of China.
Context: The rotating arc plasma technique for the synthesis of nitrogen-doped graphene capitalizes on the distinctive attributes of plasma, presenting a straightforward, efficient, and catalyst-free strategy for the production of nitrogen-doped graphene. However, experimental outcomes generally fail to elucidate the atomic-level mechanism behind this process. Our research utilizes molecular dynamics simulations to explore theoretically the formation of radicals during the plasma-driven reaction between methane (CH₄) and nitrogen (N₂).
View Article and Find Full Text PDFACS Nano
January 2025
Engineering Research Center of Forestry Biomass Materials and Bioenergy (Ministry of Education), National Forest and Grass Administration Woody Spices (East China) Engineering Technology Research Center, Beijing Forestry University, Beijing 100083, China.
Solar desalination is one of the effective means to alleviate water scarcity, in which aerogel-like evaporators have attracted extensive attention in the field of efficient desalination. However, the current preparation methods for aerogels still mainly rely on high-cost solutions, such as freeze-drying or supercritical drying. Herein, a preparation scheme for aerogels that can be realized under atmospheric pressure conditions is reported.
View Article and Find Full Text PDFDalton Trans
January 2025
Institute for Inorganic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Boriranes, highly strained three-membered cyclic organoboron heterocycles, have emerged as potential synthons for the synthesis of many organoboron species. However, the synthesis of boriranes with tricoordinate, sp-hybridised boron and tetracoordinate, sp-hybridised carbon atoms is very challenging owing to their high Lewis acidity. Herein we describe the isolation of base-free triaminoboriranes from the room-temperature reaction of diaminoalkynes with an aminodistannylborane.
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