Migration of Iron Oxide Nanoparticle through a Silica Shell by the Redox-Buffering Effect

Wang, Dawei; Wang, Xiaojing; Li, Zhiwei; Chi, Miaofang; Li, Yi; Liu, Yiding; Yin, Yadong

doi:10.1021/acsnano.8b04520

Cited by 21 publications

(22 citation statements)

References 26 publications

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“…In metal systems,f or example, formation of passivating oxides induces both adverse (e.g. non-Newtonian flow, [3] lustre,s urface defects,w ettability, metastability) [4] and advantageous (e.g.protection, catalysis, [5] redox buffering, [6] and undercooling [7] )p roperties.T hese surface oxides can grow to their equilibrium dimensions within milliseconds and passivate depending on the conditions. [8] Oxidation, however,d epends on stoichiometry,o xidant diffusion, reduction potential (E 0 ), microstructure, cohesive energy density,a tomic size,t emperature,a nd pressure.…”

Section: Introductionmentioning

confidence: 99%

Chameleon Metals: Autonomous Nano‐Texturing and Composition Inversion on Liquid Metals Surfaces

et al. 2019

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Studies on passivating oxides on liquid metals are challenging, in part, due to plasticity, entropic, and technological limitations. In alloys, compositional complexity in the passivating oxide(s) and underlying metal interface exacerbates these challenges. This nanoscale complexity, however, offers an opportunity to engineer the surface of the liquid metal under felicitous choice of processing conditions. We inferred that difference in reactivity, coupled with inherent interface ordering, presages exploitable order and selectivity to autonomously present compositionally biased oxides on the surface of these metals. Besides compositional differences, sequential release of biased (enriched) components, via fractal‐like paths, allows for patterned layered surface structures. We, therefore, present a simple thermal‐oxidative compositional inversion (TOCI) method to introduce fractal‐like structures on the surface of these metals in a controlled (tier, composition, and structure) manner by exploiting underlying stochastic fracturing process. Using a ternary alloy, a three‐tiered (in structure and composition) surface structure is demonstrated.

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Section: Introductionmentioning

confidence: 99%

Chameleon Metals: Autonomous Nano‐Texturing and Composition Inversion on Liquid Metals Surfaces

et al. 2019

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“…Figure 6a shows the transformation of Fe 3 O 4 nanoparticles upon reacting with the encapsulating SiO 2 . 48 When the Fe 3 O 4 @SiO 2 core−shell nanoparticles (Figure 6b) were heated in hydrogen gas at 500 °C for 4 h, the Fe 3 O 4 cores were reduced to FeO, which would further react with SiO 2 to form Fe 2 SiO 4 . The dissolution of Fe 2 SiO 4 in the SiO 2 shell drove the outward diffusion of iron oxide species and, accordingly, the inward diffusion of vacancies, which coalesce into voids.…”

Section: Nanoscale Transformation Driven By Interfacial Reactionsmentioning

confidence: 99%

“…Besides colloidal systems, nanoscale transformation can also be achieved by interfacial reactions in the solid state. Figure a shows the transformation of Fe 3 O 4 nanoparticles upon reacting with the encapsulating SiO 2 . When the Fe 3 O 4 @SiO 2 core–shell nanoparticles (Figure b) were heated in hydrogen gas at 500 °C for 4 h, the Fe 3 O 4 cores were reduced to FeO, which would further react with SiO 2 to form Fe 2 SiO 4 .…”

Section: Manipulation Of Interfacial Diffusionmentioning

confidence: 99%

Manipulation of Interfacial Diffusion for Controlling Nanoscale Transformation

2021

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Conspectus The unprecedented development of inorganic nanostructure synthesis has paved the way toward their broad applications in areas such as food science, agroforestry, energy conversion, and biomedicine. The precise manipulation of the nucleation and subsequent growth has been recognized as the central guiding principle for controlling the size and morphology of the nanostructures. However, conventional colloid syntheses based on direct precipitation reactions still have limitations in their versatility and extendibility. The crystal structure of a material determines the limited number of possible morphologies that its nanostructures can adopt. Further, as nucleation and growth kinetics are sensitive to not only the nature of the precipitation reactions but also ligands and ripening effect, rigorous control of reaction conditions must be established for every specific synthesis. In addition, multiple experimental parameters are entangled with each other, thereby requiring rigorous control of all reaction conditions. As a result, it is usually challenging to extend a synthetic recipe from one material to another. As an alternative method, the direct transformation of existing nanostructures into target ones has become an effective and robust approach capable of creating various complex nanostructures that are otherwise challenging to obtain using conventional methods. To this end, an in-depth understanding of nanoscale transformation toward the synthesis of inorganic nanostructures with diverse properties and applications is highly desirable. In this Account, we aim to reveal the critical effect of the interfacial diffusion on controlled nanoscale transformation. We first discuss how the interdiffusion rates determine the morphology and properties of bimetallic nanostructures. While equal interdiffusion rates lead to perfect mixing and generate fully alloyed nanostructures, interdiffusion at unequal rates creates vacancies in the fast diffusion side, which may cause dramatic morphological transformation to the nanostructures. Then, we introduce interfacial reactions, including the Kirkendall cavitation process, elimination reaction, and solid-state reaction, to promote the unbalanced interdiffusion and generalize nanoscale transformations in materials of various compositions, morphologies, and crystal structures. Finally, we discuss the use of capping ligands to inhibit the diffusion of atoms on one side of the interface in order to enable selective etching or transformation of the nanostructures. By modifying the nanostructured surface with specific capping ligands, the diffusion of surface atoms is restricted. When nanoparticles undergo chemical reactions (such as etching or heating), the outward diffusion of substances dominates, thereby successfully achieving chemical and morphological transformations. We believe that controlled interfacial diffusion can effectively manipulate nanoscale transformations, thus providing new strategies for the custom synthesis of multifunctional nanomaterials for various sp...

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“…This passivating oxide layer, however, when properly formed and/or engineered provides various advantages to a material. [46][47][48][49][50][51][52] Previous works have empirically shown the complex composition of these interface layer on a liquid binary alloy, eutectic gallium-indium EGaIn (75.5% Ga, 24.5% In), metal particles (Figure 2a-b). [5][6][7]53 On an EGaIn particle, the surface is an ordered layer of adventitious organics, a predominantly Ga 2 O 3 outer surface below which suboxides of both Ga and In are formed ( Figure 2b).…”

Section: Preamble: the Surface Oxidementioning

confidence: 99%

Complexity and Opportunities in Liquid Metal Surface Oxides

Martin

Chang

et al. 2020

Chem. Mater.

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The ability of metal alloys to rapidly oxidize in ambient condition presents both a challenge and an opportunity. Herein, we focus on opportunities buried in the passivating oxide of liquid metal particles. Recently described sub-surface complexity and order present an opportunity to frustrate homogeneous nucleation hence enhanced undercooling. Plasticity of the underlying liquid metal surface offers an autonomously repairing sub-surface hence the lowest E0 component dominates the surface unless stoichiometrically limited. This plasticity provides an opportunity to synthesize organometallic polymers that in situ self-assemble to high aspect ratio nanomaterials. An induced surface speciation implies that under the appropriate oxidant tension, the oxide thickness and composition can be tuned, leading to temperature-dependent composition inversion and so-called chameleon metals. The uniqueness of demonstrated capabilities points to the need for more exploration in this small but rather complex part of a metal alloy.

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Migration of Iron Oxide Nanoparticle through a Silica Shell by the Redox-Buffering Effect

Cited by 21 publications

References 26 publications

Chameleon Metals: Autonomous Nano‐Texturing and Composition Inversion on Liquid Metals Surfaces

Chameleon Metals: Autonomous Nano‐Texturing and Composition Inversion on Liquid Metals Surfaces

Manipulation of Interfacial Diffusion for Controlling Nanoscale Transformation

Complexity and Opportunities in Liquid Metal Surface Oxides

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