Srinoi Pannaree, Marquez Maria D, Lee Tai-Chou, Lee T Randall
Department of Chemistry and the Texas Center for Superconductivity, University of Houston, Houston, TX 77204-5003, USA.
Department of Chemical and Materials Engineering, National Central University, Jhongli City 32001, Taiwan.
Materials (Basel). 2020 Nov 4;13(21):4967. doi: 10.3390/ma13214967.
This article details the preparation of hollow gold-silver nanoshells (GS-NSs) coated with tunably thin silica shells for use in plasmon-enhanced photocatalytic applications. Hollow GS-NSs were synthesized via the galvanic replacement of silver nanoparticles. The localized surface plasmon resonance (LSPR) peaks of the GS-NSs were tuned over the range of visible light to near-infrared (NIR) wavelengths by adjusting the ratio of silver nanoparticles to gold salt solution to obtain three distinct types of GS-NSs with LSPR peaks centered near 500, 700, and 900 nm. Varying concentrations of (3-aminopropyl)trimethoxysilane and sodium silicate solution afforded silica shell coatings of controllable thicknesses on the GS-NS cores. For each type of GS-NS, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images verified our ability to grow thin silica shells having three different thicknesses of silica shell (~2, ~10, and ~15 nm) on the GS-NS cores. Additionally, energy-dispersive X-ray (EDX) spectra confirmed the successful coating of the GS-NSs with SiO shells having controlled thicknesses. Extinction spectra of the as-prepared nanoparticles indicated that the silica shell has a minimal effect on the LSPR peak of the gold-silver nanoshells.
本文详细阐述了用于等离子体增强光催化应用的、包覆有厚度可调的二氧化硅薄壳的中空金银纳米壳（GS-NSs）的制备方法。中空GS-NSs通过银纳米颗粒的电化学生成置换反应合成。通过调整银纳米颗粒与金盐溶液的比例，将GS-NSs的局域表面等离子体共振（LSPR）峰调谐至可见光到近红外（NIR）波长范围，从而获得三种不同类型的GS-NSs，其LSPR峰分别位于500、700和900 nm附近。不同浓度的（3-氨丙基）三甲氧基硅烷和硅酸钠溶液在GS-NS核上形成了厚度可控的二氧化硅壳涂层。对于每种类型的GS-NS，扫描电子显微镜（SEM）和透射电子显微镜（TEM）图像证实了我们在GS-NS核上生长具有三种不同厚度二氧化硅壳（约2、约10和约15 nm）的薄二氧化硅壳的能力。此外，能量色散X射线（EDX）光谱证实了GS-NSs成功包覆了厚度可控的SiO壳。所制备纳米颗粒的消光光谱表明，二氧化硅壳对金银纳米壳的LSPR峰影响极小。
