Graphene, a promising material with excellent properties, suffers from a major limitation in electronics due to its zero bandgap. The gas molecules adsorption has proven to be an effective approach for band regulation, which usually requires a harsh environment. Here, O ions produced with triboelectric plasma are used for in situ regulation of graphene, and the switching ratio can reach 10. The O ions physical adsorption will reduce the Fermi-level (E) of graphene. As the E of graphene is lower than the lowest unoccupied molecular orbital (LUMO) level of O-, the adsorption of O changes from uniform physical adsorption to local chemical adsorption, thereby realizing the semiconductor properties of graphene. The local graphene bandgap is calculated to be 83.4 meV by the variable-temperature experiment. Furthermore, annealing treatment can restore to 1/10 of the initial conductance. The C─O bond formed by O adsorption has low bond energy and is easy to desorb, while the C═O bond formed by adsorption on defects and edges has higher bond energy and is difficult to desorb. The study proposes a simple in situ method to investigate the microscopic process of O adsorption on the graphene surface, demonstrating a new perspective for local energy band engineering of graphene.
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http://dx.doi.org/10.1002/smll.202309318 | DOI Listing |
ACS Nano
January 2025
Key Laboratory of New Membrane Materials, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
Thermally driven membrane desalination processes have garnered significant interest for their potential in the treatment of hypersaline wastewater. However, achieving high rejection rates for volatiles while maintaining a high water flux remains a considerable challenge. Herein, we propose a thermo-osmosis-evaporation (TOE) system that utilizes molecular intercalation-regulated graphene oxide (GO) as the thermo-osmotic selective permeation layer, positioned on a hydrophobic poly(vinylidene fluoride) fibrous membrane serving as the thermo-evaporation layer.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Applied Computer Science and Modelling Department, Faculty of Metals Engineering and Industrial Computer Science, AGH University of Krakow, Czarnowiejska 66, 30-054, Krakow, Poland.
CT images of castings made of ductile iron were analyzed in the paper. On these images, objects can be identified that can be considered as graphite precipitates or indicate the presence of a defect in the casting. Research conducted in this area is described, based on experimental data that allows to determine whether the indicated components present in the casting are graphite precipitation.
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January 2025
Department of Obstetrics and Gynecology, Shengjing Hospital of China Medical University, No.36 Sanhao Street, Heping District, Shenyang, Liaoning Province, China, Shenyang, 110004, CHINA.
Molybdenum disulfide quantum dots (MoS2 QDs) is a new type of graphite like nanomaterial, which exhibited well chemical stability, unique fluorescence characteristics, and excellent biocompatibility. The conventional hydrothermal synthesis of MoS2 generally requires a long-term reaction at high temperature and high pressure. Herein, we have developed a simple and fast MoS2 QDs synthesis scheme using microwave heating, and further modified the surface of MoS2 QDs using 3-aminophenylboronic acid.
View Article and Find Full Text PDFTalanta
January 2025
School of Agricultural Engineering, Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, Jiangsu University, Zhenjiang, Jiangsu, 212013, China; College of Agricultural Equipment Engineering, Henan University of Science and Technology, Luoyang, Henan, 471003, China. Electronic address:
Searching for new alternative to tripropylamine (TPrA) with low toxicity and high chemical stability for the tris(4,4'-dicarboxylic acid-2,2'-bipyridyl)ruthenium (II) (Ru(dcbpy)) based coreactant electrochemiluminescence (ECL) system is essential for widespread analytical applications. Here, nitrogen-doped graphene quantum dots (NGQDs) have been discovered to significantly amplify the ECL emission and increase the ECL efficiency of Ru(dcbpy) for the first time. However, the mechanism by which NGQDs act as coreactants is not well comprehended.
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January 2025
Department of Electrical and Computer Engineering, Nazarbayev University, Nazarbayev University, Astana, Kazakhstan, Astana, 010000, KAZAKHSTAN.
Non-equilibrium molecular dynamics (NEMD) simulations reveal the existence of a spontaneous heat current (SHC) in the absence of a temperature gradient and demonstrate ultra-high thermal rectification in asymmetric trapezoid-shaped graphene. These unique properties have potential applications in power generation and thermal circuits, functioning as thermal diodes. Our findings also show the presence of negative and zero thermal conductivity in this system.
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