Samanta Subarna, Paul Sujay, Debnath Tushar
Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
Small. 2024 May;20(19):e2311712. doi: 10.1002/smll.202311712. Epub 2024 Jan 23.
Water-hexane interfacial preparation of photostable Au@CsPbBr (Au@CPB) hybrid nanocrystals (NCs) from pure CsPbBr (CPB) NCs is reported, with the coexistence of exciton and localized surface plasmon resonance with equal dominance. This enables strong exciton-plasmon coupling in these plasmonic perovskite NCs where not only the photoluminescence is quenched intrinsically due to ultrafast charge separation, but also the light absorption property increases significantly, covering the entire visible region. Using a controlled interfacial strategy, a reversible chemical transformation between CPB and Au@CPB NCs is shown, with the simultaneous eruption of larger-size ligand-free aqueous Au nanoparticles (NPs). An adsorption-desorption mechanism is proposed for the reversible transformation, while the overgrowth reaction of the Au NPs passes through the Au aggregation intermediate. This study further shows that the plasmonic Au@CPB hybrid NCs as well as ligand-free Au NPs exhibit clear surface enhanced Raman scattering (SERS) effect of a commercially available probe molecule. Overall, the beautiful interfacial chemistry delivers two independent plasmonic materials, i.e., Au@CPB NCs and ligand-free aqueous Au NPs, which may find important implications in photocatalytic and biomedical applications.
报道了从纯 CsPbBr（CPB）纳米晶体（NCs）通过水 - 己烷界面制备光稳定的 Au@CsPbBr（Au@CPB）混合纳米晶体，其中激子和局域表面等离子体共振共存且具有同等优势。这使得这些等离子体钙钛矿 NCs 中能够实现强激子 - 等离子体耦合，不仅由于超快电荷分离使光致发光本质上被淬灭，而且光吸收性能显著提高，覆盖整个可见光区域。采用可控的界面策略，展示了 CPB 和 Au@CPB NCs 之间的可逆化学转变，同时会有更大尺寸的无配体水性金纳米颗粒（NPs）喷发出来。针对这种可逆转变提出了一种吸附 - 解吸机制，而金 NPs 的过生长反应通过金聚集中间体进行。该研究进一步表明，等离子体 Au@CPB 混合 NCs 以及无配体金 NPs 对一种市售探针分子表现出明显的表面增强拉曼散射（SERS）效应。总体而言，这种美妙的界面化学产生了两种独立的等离子体材料，即 Au@CPB NCs 和无配体水性金 NPs，它们可能在光催化和生物医学应用中具有重要意义。
