一、 鈀氧化亞銅及金奈米棒氧化亞銅核殼結構與其晶面相關 之光學探討 二、 金氧化亞銅核殼結構之可調性近紅外光表面電漿吸收產 生之有效光熱作用

I. Facet-Dependent Optical Properties of Pd-Cu2O and Au rod-Cu2O Core-Shell Nanocrystals II. Photothermal Effects Generated from Au-Cu2O Core-Shell Nanocrystals with Tunable NIR SPR Absorption Band

王祥儒

指導教授 ： 黃暄益

國立清華大學/理學院/化學系/碩士(2014年)

https://doi.org/10.6843/NTHU.2014.00247

摘要

先前我們透過以八面體的金核合成奈米立方體、截半立方體及八面體的金氧化亞銅核殼結構，已證實氧化亞銅晶體其與晶面有關之光學性質。金的表面電漿共振吸收峰因為氧化亞銅的高折射率而大幅紅位移且保持在固定的位置而無關乎殼的厚度改變。然而，改變殼的表面晶面，金的表面電漿共振吸收峰在立方體及八面體的金氧化亞銅核殼結構相差達到26奈米，且氧化亞銅的殼本身也出現與晶面有關之光學性質。在第一個環節中，我們同樣觀察到光學性質的晶面相關性也出現在鈀氧化亞銅及金奈米棒氧化亞銅核殼結構中。但是，在正方體中，鈀的表面電漿共振吸收峰卻比八面體更為藍位移，與在金氧化亞銅結構中相反。金奈米短棒的長軸電漿共振吸收峰也因氧化亞銅而紅位移至第二生物窗口。第二個部分中，小尺寸的金氧化亞銅核殼結構第一次被應用在光熱效應中，以近紅外光雷射加熱經過300秒後溫度可從室溫提升至 65 ºC，此現象可應用於將太陽能轉換為熱能。藉由包上氧化亞銅可增加吸收截面積且調控金的表面電漿吸收，此外，金奈米粒子穩定性也可得到提升，而非於照射後會發生變形。這些結構有潛力可發展為極小且高效能的電漿加熱器。

關鍵字

鈀 ； 金 ； 氧化亞銅 ； 表面電漿共振 ； 光熱

並列摘要

Previously we showed that the optical properties of Cu2O crystals are facet-dependent by examining Au‒Cu2O core‒shell nanocubes, cuboctahedra, and octahedra with octahedral gold cores. The substantially red-shifted Au surface plasmon resonance (SPR) absorption band due to the Cu2O shell with a large refractive index remains fixed despite changes in the shell thickness. However, tuning the shell shape, and hence the surface facet, the Au SPR band can differ by as much as 26 nm. The Cu2O shells also display facet-dependent optical properties. Here in the first study, we examined if the same facet-dependent optical properties are observable in Pd‒Cu2O and Au nanorod‒Cu2O core‒shell nanocrystals. Nicely, the same facet-dependent optical properties are observed in these nanostructures. However, the Pd SPR band in Pd‒Cu2O cubes is more blue-shifted than Pd‒Cu2O truncated octahedra, whereas in the Au‒Cu2O case the Au SPR band of cubes is more red-shifted than octahedra. The short Au nanorod cores shift the SPR band directly to 1010‒1235 nm into the second biological window with the Cu2O shells. The small Au‒Cu2O core‒shell nanocrystals were tested for photothermal effect for the first time. Remarkably, giving enough near-IR irradiation energy, the ethanol solvent containing Au‒Cu2O nanoparticles can raise the temperature to 65 ºC after 300 sec from room temperature. This property can be exploited for converting sun light to thermal energy. Au nanoparticles can deform after long illumination time. By coating Cu2O shells outside Au cores, the stability and absorption cross section will increase and the LSPR property is tunable by changing the shell morphology and using short rods. These structures have potential as ultrasmall and highly efficient plasmonic heaters.

並列關鍵字

Pd ； Au ； Cu2O ； surface plasmon resonance ； photothermal

參考文獻

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