BIOSCOPE Research Group, LAQV-REQUIMTE, Chemistry Department, NOVA School of Science and Technology, FCT NOVA, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
PROTEOMASS Scientific Society, Rúa dos Inventores, Madan Parque, Caparica Campus, 2829-516 Caparica, Portugal.
J Phys Chem Lett. 2023 Jul 13;14(27):6315-6320. doi: 10.1021/acs.jpclett.3c01431. Epub 2023 Jul 6.
Bimetallic nanostructures composed of gold (Au) and palladium (Pd) have garnered increased interest for their applications in heterogeneous catalysis. This study reports a simple strategy for manufacturing Au@Pd bimetallic branched nanoparticles (NPs), which offer a tunable optical response, using polyallylamine-stabilized branched AuNPs as template cores for Pd overgrowth. The palladium content can be altered by manipulating the concentration of PdCl and ascorbic acid (AA) that are injected, which permit an overgrowth of the Pd shell up to ca. 2 nm thick. The homogeneous distribution of Pd at the surfaces of Au NPs can be carried out regardless of their size or branching degree, which allows for an adjustment of the plasmon response in the near-infrared (NIR) spectral range. As a proof of concept, the nanoenzymatic activity of pure gold and gold-palladium NPs was compared, exploring their peroxidase-like activity in the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB). The bimetallic AuPd NPs demonstrate an increase in the catalytic properties attributed to the presence of palladium at the surface of gold.
由金（Au）和钯（Pd）组成的双金属纳米结构因其在多相催化中的应用而引起了越来越多的关注。本研究报告了一种制造 Au@Pd 双金属支化纳米颗粒（NPs）的简单策略，该策略使用聚烯丙胺稳定的支化 AuNPs 作为模板核，通过 Pd 的过度生长来提供可调谐的光学响应。可以通过改变注入的 PdCl 和抗坏血酸（AA）的浓度来改变钯的含量，这允许 Pd 壳的过度生长达到约 2nm 厚。钯在 Au NPs 表面的均匀分布可以在不考虑其大小或分支度的情况下进行，这允许在近红外（NIR）光谱范围内调整等离子体响应。作为概念验证，比较了纯金和金钯 NPs 的纳米酶活性，探索了它们在 3,3',5,5'-四甲基联苯胺（TMB）氧化中的过氧化物酶样活性。双金属 AuPd NPs 表现出催化性能的提高，这归因于钯在金表面的存在。
