Anisotropic and Multicomponent Nanostructures by Controlled Symmetry Breaking of Metal Halide Intermediates

Abstract

We propose and validate herein a solution-phase synthetic strategy relying on in situ photostimulation and reduction of metal-halide intermediates to yield complex anisotropic and multicomponent nanostructures. Exposure of AgBr nanoparticles to ultraviolet light and l-Arginine forms dimers composed of crystalline Ag and AgBr nanophases. The Ag nanoparticle nucleates at and grows from a single point on the surface of the AgBr phase and the interface connecting these phases is atomically sharp. The complex nanostructures are generated at greater than 80% yield and are highly monodisperse in morphology and in size. The high crystallinity of the nanophases arises from an apparent solid-solid crystallization process and is unusual considering the nearly 40% lattice mismatch between Ag and AgBr. Such structures may be used to interrogate photocatalytic mechanisms or to construct more complex materials.

Symmetry Breaking Induced by Growth Kinetics: One‐Pot Synthesis of Janus Au−AgBr Nanoparticles

“…It should be noted that, only recently, an AgÀ AgBr dimer with an anisotropic nanostructure has been reported. [19] In this study, we propose a new strategy for the one-pot growth of AuÀ AgBr NPs as shown in Figure 1b. Contrary to the typical processes that form AgÀ AgX materials (Figure 1a), chemically stable Au NPs are first formed by photoreduction of Au complexes, and then AgBr nanocrystals are deposited on part of the surface of the Au NPs, resulting in the formation of AuÀ AgBr NPs.…”

“…This limits the application of these materials due to the limited stability of metallic Ag, which is prone to undergo oxidation, with the subsequent formation of many kinds of Ag compounds. It should be noted that, only recently, an Ag−AgBr dimer with an anisotropic nanostructure has been reported …”

A review of recent advances in the use of complex metal nanostructures for biomedical applications from diagnosis to treatment

“…Among nanomaterials, metal nanostructures have gained significant attention in the field of biomedical research due to several properties. These include advanced abilities to engineer their surface chemistry, methods to create sophisticated three‐dimensional shapes, bio‐inertness (and thus biocompatibility) as well as their highly useful optical properties (Fichthorn, 2023; Kossak et al, 2018; Tang & Wei, 2012). These nanostructures are also characterized by strong local surface plasmon resonances (Lee et al, 2016; Sherry et al, 2005; Xiong, Chen, et al, 2005), high x‐ray absorption coefficients, and compatibility with a wide variety of ligands and surfactants, which increasingly make them applicable in various fields of biomedicine (Dong et al, 2019; Hajfathalian et al, 2018; G. Wang, Gao, Zhang, & Mei, 2016).…”