Monolayer and bilayer graphene films with a few hundred nm domain size were grown on ultraprecision figured 4H-SiC(0001) on-axis and 8 degrees -off surfaces by annealing in ultra-high vacuum. Using X-ray photoelectron spectroscopy (XPS), atomic force microscopy, reflection high-energy electron diffraction, low-energy electron diffraction (LEED), Raman spectroscopy, and scanning tunneling microscopy, we investigated the structure, number of graphene layers, and chemical bonding of the graphene surfaces. Moreover, the magnetic property of the monolayer graphene was studied using in-situ surface magneto-optic Kerr effect at 40 K. LEED spots intensity distribution and XPS spectra for monolayer and bilayer graphene films could become an obvious and accurate fingerprint for the determination of graphene film thickness on SiC surface.
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http://dx.doi.org/10.1166/jnn.2011.3893 | DOI Listing |
ACS Appl Mater Interfaces
December 2024
Institute of Chemical Engineering Sciences, Foundation of Research and Technology- Hellas (FORTH/ICE-HT), Stadiou Street, Platani, Patras 26504, Greece.
Due to their outstanding electrical and thermal properties, graphene and related materials have been proposed as ideal candidates for the development of lightweight systems for thermoelectric applications. Recently, the nanolaminate architecture that entails alternation of continuous graphene monolayers and ultrathin polymer films has been proposed as an efficient route for the development of composites with impressive physicochemical properties. In this work, we present a novel layer-by-layer approach for the fabrication of highly ordered, flexible, heat-resistant, and electrically conductive freestanding graphene/polymer nanolaminates through alternating Marangoni-driven self-assembly of reduced graphene oxide (rGO) and poly(ether imide) (PEI) films.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
School of Power & Mechanical Engineering, Wuhan University, Wuhan 430072, China.
TiZrMoC coatings were deposited on Si(100) substrates using a DC dual magnetron sputtering. The composition was controlled by adjusting the sputtering parameters of the TiZrMo and graphite targets. The influence of graphite target current on the resulting coating properties was explored.
View Article and Find Full Text PDFNano Lett
December 2024
State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an 710072, P. R. China.
Dion-Jacobson (DJ) perovskites are promising alternatives for Ruddlesden-Popper (RP) perovskites to fabricate blue perovskite light-emitting diodes (PeLEDs) due to their favorable structural and charge properties. However, the relatively weak hydrogen bond between the bridging diammonium group and perovskite poses huge challenges for regulating crystallization and defect density, leading to an undesirable film quality and device performance. Herein, we report the successful optimization of DJ perovskite films by introducing a new type of cesium octafluoroadipate (CsOFAA) precursor, which could strongly anchor the perovskite through coordination bonds and halogen-halogen bonds.
View Article and Find Full Text PDFHeliyon
December 2024
College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, 010021, China.
Graphene and its derivatives are widely used in various fields due to their unique two-dimensional lamellar structure. This study aims to synthesize ultra-large graphene oxide (GO) sheets from natural flake graphite and investigate the factors influencing their size. Using a two-intercalation method based on the modified Hummers' method, we address the challenge of intercalating large-diameter graphene oxide by employing a secondary intercalation technique.
View Article and Find Full Text PDFFood Chem
December 2024
Sensors and Biosensors Group, Analytical Chemistry and Electrochemistry Lab (LR99ES15), University of Tunis El Manar, Tunis El Manar, 2092 Tunis, Tunisia. Electronic address:
Improper use and harmful effects of nitrite ions pose a significant risk to human health. To address this concern, the use of carbon-based materials for electrochemical sensing is regarded as one of the most promising detection tools for ensuring the quality of drinking water and food products. In this context, we developed laser-ablated graphene electrodes (LAGEs) by direct laser scribing on a polyimide substrate, which were subsequently modified by electrochemical deposition of a redox-active melanin-like film (MeLF/LAGEs).
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