Ag–Ag₂S Hybrid Nanoprisms: Structural versus Plasmonic Evolution

Abstract

Recently, Ag-Ag2S hybrid nanostructures have attracted a great deal of attention due to their enhanced chemical and thermal stability, in addition to their morphology- and composition-dependent tunable local surface plasmon resonances. Although Ag-Ag2S nanostructures can be synthesized via sulfidation of as-prepared anisotropic Ag nanoparticles, this process is poorly understood, often leading to materials with anomalous compositions, sizes, and shapes and, consequently, optical properties. In this work, we use theory and experiment to investigate the structural and plasmonic evolution of Ag-Ag2S nanoprisms during the sulfidation of Ag precursors. The previously observed red-shifted extinction of the Ag-Ag2S hybrid nanoprism as sulfidation occurs contradicts theoretical predictions, indicating that the reaction does not just occur at the prism tips as previously speculated. Our experiments show that sulfidation can induce either blue or red shifts in the extinction of the dipole plasmon mode, depending on reaction conditions. By elucidating the correlation with the final structure and morphology of the synthesized Ag-Ag2S nanoprisms, we find that, depending on the reaction conditions, sulfidation occurs on the prism tips and/or the (111) surfaces, leading to a core(Ag)-anisotropic shell(Ag2S) prism nanostructure. Additionally, we demonstrate that the direction of the shift in the dipole plasmon is a function of the relative amounts of Ag2S at the prism tips and Ag2S shell thickness around the prism.

Broadband absorption and enhanced photothermal conversion property of octopod-like Ag@Ag2S core@shell structures with gradually varying shell thickness

“…In the current work, Ag nanocubes with spatially different reactivity were applied as templates, which eventually resulted in gradually varying shell thickness in the synthesized Ag@Ag 2 S core@shell structures. Previously, Ag-Ag 2 S hybrids of different shapes including nanowires 24 , nanocubes 15 , 25 , triangular nanoplates 15 , and nanoprisms 26 , 27 were synthesized via the sulfudition of the corresponding Ag nanocrystals. In those studies, the resulting hybrids possessed the same shapes as the Ag nanocrystals.…”

Photo‐assisted electrochemical hydrogen evolution by plasmonic Ag nanoparticle/nanorod heterogeneity

“…Figure D displays the spectra of Ni 2p for the three samples, where the two peaks located at 873.6 eV (2p1/2) and 855.9 eV (2p3/2) indicate the binding energy of Ni 2+ . Representatively, the deconvoluted peaks located at 373.8 and 367.8 eV are attributed to Ag 0 3d3/2 and 3d5/2 for the ANS‐2 sample . Meanwhile, the presence of Ag + is also identified in ANS‐2, with the peaks located at 373.5 and 367.5 eV .…”

“…22 Representatively, the deconvoluted peaks located at 373.8 and 367.8 eV are attributed to Ag 0 3d3/2 and 3d5/2 for the ANS-2 sample. 23 Meanwhile, the presence of Ag + is also identified in ANS-2, with the peaks located at 373.5 and 367.5 eV. 24 Notably, the intensity of Ag + binding peaks is proportional to the sulfurization extent, revealing the relocation of Ag during the sulfurization process ( Figure S6).…”

Photoactive Hybrid AuNR‐Pt@Ag2S Core–Satellite Nanostructures for Near‐Infrared Quantitive Cell Imaging

“…The unique nanoassembly, core–satellite, has attracted much attention from researchers . Ag 2 S quantum dots have been used to ultrasensitively detect miR using second‐window near‐infrared (NIR‐II) fluorescent signals and have many advantages, including their high biological compatibility, diffraction‐limited spatial resolution, and fast feedback . Platinum (Pt) decorated gold nanorods (AuNR‐Pt) were synthetized with a heterogeneous seed‐mediated growth method, and displayed better optical and catalytic properties .…”