With the development of modern nanoscience and technology, the research on the preparation and controllable optical properties of noble metal nanohybrids has aroused people’s wide interest, including optoelectronics, new energy, industrial catalysis, metamaterials, sensing technology, biomedical, etc. Many fields have broad application prospects. The excellent physicochemical properties represented by the surface plasmon resonance (SPR) effect of noble metals (especially Au and Ag) nanocrystals are closely related to their size, morphology and composition, and they can reasonably control the growth of precious metal nanomaterials. Further effective control of its size, dimensions, composition, crystal structure and even physical properties is of great significance for the in-depth study of the relationship between precious metal structures and physical properties and the ultimate realization of designing synthetic functional nanocomposites in accordance with people's wishes.
The Institute of Optics and Photonics, Chinese Academy of Sciences, has made new progress in the research of noble metal nanocrystalline super-crystalline materials based on surface plasmon resonance: Preparation of low-crystalline octahedron to high-crystalline surface by one-step chemical reduction The dodecahedron has a variety of regular gold nanocrystal superstructures and has undergone an in-depth study of its excellent surface plasmon resonance absorption characteristics. The relevant research results have been published in the recent issue of the Journal of the Chinese Journal of Materials Chemistry, J. Mater. Chem. C, 2017, 5, 645.
The study selected a controlled and efficient polyol preparation method that is green, efficient, simple, and can be used for large-scale production. Cationic surfactant, polydiallyldimethylammonium chloride (PDDA), was used as a morphology guide. , Ethylene glycol (EG) / pentanediol (PD) as a solvent and reducing agent, the next step in the high-temperature environment reduction of gold chloride (HAuCl4) direct synthesis to obtain the desired gold nanocrystal superstructure. The SEM, TEM and XRD characterization results show that the obtained octahedron, truncated octahedron and trihedral gold nanocrystal supercrystals all have a yield of more than 95%. They have unique morphology and uniform size distribution (57 nm to 85 nm). Nm) is a standard face-centered cubic single crystal structure; the visible-near-infrared absorption spectrum measurements over time show that different gold nanocrystals have a strong and wide wavelength range from 552 nm to 568 nm. The surface plasmon resonance absorbs and is accompanied by a pronounced redshift phenomenon. At the same time, all the synthesized gold nanocrystal superstructures and their resonant absorption characteristics can be stable for a long time, and they are expected to be applied in the field of surface plasmon polariton, optoelectronics, and self-assembly metamaterials in the future.
Low Crystalline Octahedron-High Crystalline Twenty-Second Surface Au Nanocrystal Superstructure and Its SPR Effect
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