CIC biomaGUNE and CIBER-BBN, Paseo Miramón 182, 20014 Donostia-San Sebastián, Spain.
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
Nanoscale. 2019 Nov 7;11(41):19561-19570. doi: 10.1039/c9nr05679c. Epub 2019 Oct 4.
Bimetallic gold-palladium particles were originally proposed as catalysts with tunable reaction rates. Following the development of synthesis routes that offer better control on the morphology and composition of the particles, novel optical sensing functionalities were more recently proposed. Since temperature is a fundamental parameter that interplays with every other proposed application, we studied the light-to-heat conversion ability of Au/Pd bimetallic nanoparticles with a regular octapodal shape. Both compositional (Au-to-Pd ratio) and structural (diagonal tip-to-tip distance and tip width) characteristics were screened and found to be essential control parameters to promote light absorption and efficient conversion into heat. Electromagnetic simulations reveal that the Pd content, and specifically its distribution inside the branched particle geometry, has a profound impact on the optical properties and is an essential criterion for efficient heating. Notably, the optical and photothermal responses are shown to remain stable throughout extended illumination, with no noticeable structural changes to the branched nanocrystals due to heat generation.
双金属金钯颗粒最初被提议作为具有可调反应速率的催化剂。在开发出能够更好地控制颗粒形态和组成的合成路线之后，最近又提出了新颖的光学传感功能。由于温度是与每个其他提出的应用相互作用的基本参数，我们研究了具有规则八叉形的 Au/Pd 双金属纳米颗粒的光热转换能力。对组成（金与钯的比例）和结构（对角尖端到尖端的距离和尖端宽度）特征进行了筛选，发现它们是促进光吸收和高效转化为热的基本控制参数。电磁模拟表明，Pd 的含量，特别是其在分支颗粒几何形状内的分布，对光学性质有深远的影响，是有效加热的必要条件。值得注意的是，光学和光热响应在延长的照明下保持稳定，由于热的产生，分支纳米晶体没有明显的结构变化。
