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2Laser-synthesized orthorhombic carbon flakes intercalated with Au-Ag nanoparticles as advanced optical material
A. Manshina
Institute of chemistry, St. Petersburg State University, 26 Universitetskii prospect, Petergof St. Petersburg, 198504, Russia
The hybrid nanomaterials possess a wide spectrum of important properties that may be gained by controllably varying such parameters as their composition, structure and morphology. In addition, combining of different components in the same structure and their mutual influence enables obtaining materials that exhibit not only additive properties of the components but also new ones caused by synergetic effects.
Here we present the hybrid nanomaterial never realized before - combination of crystalline 2D carbon and incorporated bimetal Au-Ag nanoclusters [1-3]. Our experiments on laser-induced synthesis demonstrate the possibility of the direct creation of 2D hybrid metal/carbon flakes in just one step. The deposited flakes were found to be atomically smooth, regularly shaped flat structures of 1-2 ^m x 4-7 ^m with thickness of 10 - 100 nm, which consist of bimetal Au-Ag nanoclusters c.a. 3 nm in diameter stochastically distributed in crystalline carbonaceous matrix (Figure 1a). The carbonaceous matrix itself differs from known allotropes of carbon, and was found to be hydrogenated carbon with pure sp2 hybridization and orthorhombic crystal cell.
Figure 1. a) SEM image of the single hybrid flake, b) local modification of a nanoflake with focused helium-ion beam.
We found that the hybrid flakes can be cut or/and modified by means of irradiation with a focused helium ion beam (FIB) - Fig. 1b. Au-Ag@C flakes are very promising hybrid material with extraordinary potential in terms of its optical properties thanks to enhanced characteristics resulting from synergetic effects of their components - pronounced SERS effect, high birefringence, luminescence.
This work was supported by RSF project 23-49-10044. Authors are grateful to "Centre for Optical and Laser materials research" and "Interdisciplinary Resource Centre for Nanotechnology" Research Park of Saint Petersburg State University for technical support.
[1] A. Povolotckaia, et al, Plasmonic carbon nanohybrids from laser-induced deposition: controlled synthesis and SERS properties, J Mater Sci 54:8177-8186, (2019).
[2] M. Butt, et al, Investigating the Optical Properties of a Laser Induced 3D Self-Assembled Carbon-Metal Hybrid Structure, Small, 15, 1900512, (2019).
[3] M. Butt, et al, Hybrid orthorhombic carbon flakes intercalated with bimetallic Au-Ag nanoclusters: influence of synthesis parameters on optical properties, Nanomaterials 10 (7), 1376 (2020).
