Integration of Kinetic Control and Lattice Mismatch To Synthesize Pd@AuCu Core–Shell Planar Tetrapods with Size-Dependent Optical Properties
2016; American Chemical Society; Volume: 16; Issue: 5 Linguagem: Inglês
10.1021/acs.nanolett.6b00002
ISSN1530-6992
AutoresMin Meng, Zhicheng Fang, Chao Zhang, Hongyang Su, Rong He, Renpeng Zhang, Hongliang Li, Zhiyuan Li, Xiaojun Wu, Chao Ma, Jie Zeng,
Tópico(s)Quantum Dots Synthesis And Properties
ResumoPlanar nanocrystals with multiple branches exhibit unique localized surface plasmon resonance properties and great promise in optical applications. Here, we report an aqueous synthesis of Pd@AuCu core–shell planar tetrapods through preferential overgrowth on Pd cubic seeds. The large lattice mismatch between the Pd core and the AuCu shell is the key to induce the formation of branches under sluggish reduction kinetics. Meanwhile, the capping effect of cetyltrimethylammonium chloride on the {100} facets of Pd cubes with an aspect ratio of 1.2 can determine the growth direction of AuCu branches to form a planar structure. Through simply varying the amounts of Pd cubic seeds, the sizes of products can be well-controlled in the range from 33 to 70 nm. With the manipulation of sizes, the peak position of in-plane dipole resonance can be adjusted from visible to near-infrared region. Due to the presence of tips and edges in the branches, planar tetrapods exhibited excellent surface-enhanced Raman scattering performance with an enhancement factor up to 9.0 × 103 for 70 nm Pd@AuCu planar tetrapods.
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