Abstract:
Hybrid nanomaterials containing both noble metal and semiconductor building blocks provide an engineerable platform for realizing direct or indirect charge and energy transfer for enhanced plasmonic photoconversion and photocatalysis. In this work, silver nanoparticles (AgNPs) and chalcopyrite (CuFeS2) nanocrystals (NCs) are combined into a AgNP@CuFeS2 hybrid structure comprising NCs embedded in a self-assembled lipid coating around the AgNP core. In AgNP@CuFeS2 hybrid structures, both metallic and semiconductor NCs support quasistatic resonances. To characterize the interactions between these resonances and their effect on potential charge and energy transfer, direct interfacial excitation transfer between the AgNP core and surrounding CuFeS2 NCs is probed through single particle line shape analysis and supporting electromagnetic simulations. These studies reveal that CuFeS2 NCs localized in the evanescent field of the central AgNP induce a broadening of the metal NP line shape that peaks when an energetic match between the AgNP and CuFeS2 NC resonances maximizes direct energy transfer. Dimers of AgNPs whose resonances exhibit poor energetic overlap with the CuFeS2 NC quasistatic resonance yield much weaker line shape broadening in a control experiment, corroborating the existence of resonant energy transfer in the AgNP@CuFeS2 hybrid. Resonant coupling between the metallic and semiconductor building blocks in the investigated hybrid architecture provides a mechanism for utilizing the large optical cross-section of the central AgNP to enhance the generation of reactive charge carriers in the surrounding semiconductor NCs for potential applications in photocatalysis.
摘要:
包含贵金属和半导体构造块的混合纳米材料提供了可工程的平台,用于实现直接或间接电荷和能量转移,以增强等离子体光转换和光催化作用。在这项工作中,将银纳米颗粒(AgNP)和黄铜矿(CuFeS2)纳米晶体(NC)组合成AgNP@CuFeS2混合结构,其包含嵌入在AgNP核周围的自组装脂质涂层中的NC。在AgNP@CuFeS2杂化结构中,金属和半导体NC都支持准静态共振。为了表征这些共振之间的相互作用及其对潜在电荷和能量转移的影响,AgNP核心和周围的CuFeS2NCs之间的直接界面激励传递通过单粒子线形状分析和支持电磁模拟进行探测。这些研究表明,位于中央AgNP的渐逝场中的CuFeS2NC会引起金属NP线形变宽,当AgNP和CuFeS2NC共振之间的能量匹配使直接能量转移最大化时,该线形达到峰值。在对照实验中,其共振与CuFeS2NC准静态共振表现出较差的能量重叠的AgNPs的尺寸产生的线形变宽要弱得多,证实了AgNP@CuFeS2杂化物中共振能量转移的存在。所研究的混合结构中的金属和半导体结构单元之间的共振耦合提供了一种机制,用于利用中央AgNP的大光学横截面来增强周围半导体NC中反应性电荷载流子的产生,以用于光催化的潜在应用。