Sullivan Connor S, Mason Noah L, Branco Anthony J, Jeong Sangmin, Badru Oluwatosin O, Ross Michael B
Department of Chemistry, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States.
J Phys Chem C Nanomater Interfaces. 2025 Jun 9;129(24):11070-11076. doi: 10.1021/acs.jpcc.5c00563. eCollection 2025 Jun 19.
The synthesis of Au-Sn nanoparticles with tailorable localized surface plasmon resonances (LSPR) is explored, with a focus on size dependence, composition, and phase formation. Au-Sn nanoparticles were synthesized starting from Au seeds ranging in diameter from 5 to 30 nm. UV-visible spectroscopy revealed controllable blueshifting of the LSPR, from 520 to 460 nm, as Sn incorporation increased. X-ray diffraction (XRD) confirmed the formation of AuSn and AuSn intermetallic phases, with intermetallic formation dependent on both nanoparticle size and Sn content. Elemental analysis through energy-dispersive X-ray spectroscopy (EDS), total reflectance X-ray fluorescence (TXRF), and inductively coupled plasma optical emission spectroscopy (ICP-OES) provided further insight into the incorporation of Sn into Au nanoparticle seeds. We show that this approach allows one to create Au-Sn alloy nanoparticles of varying radii and crystalline phase contents all with the same LSPR (500 nm). Additionally, the size-dependent formation of intermetallic phases provides new physical insight into their impact on the LSPR. Formation of Au Sn is associated with minimal blueshifting and broadening and AuSn is associated with linear blueshifting and a small amount of broadening, while AuSn formation leads to rapid blueshifting, broadening, and plasmon damping. This understanding enables precise control over the size, structure, and optical properties of Au-Sn nanoparticles, paving the way for the design of new plasmonic materials for applications in sensing, imaging, and catalysis.
本文探索了具有可定制局域表面等离子体共振（LSPR）的金 - 锡纳米颗粒的合成，重点关注尺寸依赖性、组成和相形成。金 - 锡纳米颗粒是从直径为5至30纳米的金种子开始合成的。紫外 - 可见光谱显示，随着锡掺入量的增加，LSPR发生可控的蓝移，从520纳米移至460纳米。X射线衍射（XRD）证实了AuSn和AuSn金属间相的形成，金属间相的形成取决于纳米颗粒的尺寸和锡含量。通过能量色散X射线光谱（EDS）、全反射X射线荧光（TXRF）和电感耦合等离子体发射光谱（ICP - OES）进行的元素分析，进一步深入了解了锡掺入金纳米颗粒种子的情况。我们表明，这种方法能够制备出具有相同LSPR（500纳米）但半径和晶相含量不同的金 - 锡合金纳米颗粒。此外，金属间相的尺寸依赖性形成为其对LSPR的影响提供了新的物理见解。AuSn的形成与最小的蓝移和展宽相关，AuSn与线性蓝移和少量展宽相关，而AuSn的形成导致快速蓝移、展宽和等离子体阻尼。这种认识使得能够精确控制金 - 锡纳米颗粒的尺寸、结构和光学性质，为设计用于传感、成像和催化应用的新型等离子体材料铺平了道路。
