Synthesis of Bifunctional Au/Pt/Au Core/Shell Nanoraspberries for in Situ SERS Monitoring of Platinum-Catalyzed Reactions

2011 ◽  
Vol 133 (48) ◽  
pp. 19302-19305 ◽  
Author(s):  
Wei Xie ◽  
Christoph Herrmann ◽  
Karsten Kömpe ◽  
Markus Haase ◽  
Sebastian Schlücker
Keyword(s):  
Core Shell ◽  
Catalyzed Reactions

scholarly journals In-situ Electrochemical Synthesis of Core-shell Structural NbC@Nb5Si3/Nb Composites in Molten Salt

2021 ◽  
Vol 714 (3) ◽  
pp. 032008
Author(s):  
Hongmei Li ◽  
Zhisheng Nong ◽  
Qian Xu ◽  
Qiushi Song ◽  
Ying Chen ◽  
...  
Keyword(s):  
Molten Salt ◽  
Electrochemical Synthesis ◽  
Core Shell

scholarly journals Morphology Controlled Synthesis of γ-Al2O3 Nano-Crystallites in Al@Al2O3 Core–Shell Micro-Architectures by Interfacial Hydrothermal Reactions of Al Metal Substrates

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 310
Author(s):  
Dohyeon Han ◽  
Doohwan Lee
Keyword(s):  
Electrostatic Interactions ◽  
Heterogeneous Catalysts ◽  
Metal Substrate ◽  
Inorganic Anions ◽  
Core Shell ◽  
Hydroxyl Groups ◽  
Hydrothermal Reactions ◽  
Fine Control ◽  
Reaction Processes

Fine control of morphology and exposed crystal facets of porous γ-Al2O3 is of significant importance in many application areas such as functional nanomaterials and heterogeneous catalysts. Herein, a morphology controlled in situ synthesis of Al@Al2O3 core–shell architecture consisting of an Al metal core and a porous γ-Al2O3 shell is explored based on interfacial hydrothermal reactions of an Al metal substrate in aqueous solutions of inorganic anions. It was found that the morphology and structure of boehmite (γ-AlOOH) nano-crystallites grown at the Al-metal/solution interface exhibit significant dependence on temperature, type of inorganic anions (Cl−, NO3−, and SO42−), and acid–base environment of the synthesis solution. Different extents of the electrostatic interactions between the protonated hydroxyl groups on (010) and (001) facets of γ-AlOOH and the inorganic anions (Cl−, NO3−, SO42−) appear to result in the preferential growth of γ-AlOOH toward specific crystallographic directions due to the selective capping of the facets by adsorption of the anions. It is hypothesized that the unique Al@Al2O3 core–shell architecture with controlled morphology and exposed crystal-facets of the γ-Al2O3 shell can provide significant intrinsic catalytic properties with enhanced heat and mass transport to heterogeneous catalysts for applications in many thermochemical reaction processes. The direct fabrication of γ-Al2O3 nano-crystallites from Al metal substrate with in-situ modulation of their morphologies and structures into 1D, 2D, and 3D nano-architectures explored in this work is unique and can offer significant opportunities over the conventional methods.

scholarly journals In Situ Study of the Wet Chemical Etching of SiO2 and Nanoparticle@SiO2 Core–Shell Nanospheres

2021 ◽  
Author(s):  
Albert Grau-Carbonell ◽  
Sina Sadighikia ◽  
Tom A. J. Welling ◽  
Relinde J. A. van Dijk-Moes ◽  
Ramakrishna Kotni ◽  
...  
Keyword(s):  
Chemical Etching ◽  
Core Shell ◽  
In Situ Study ◽  
Wet Chemical ◽  
Wet Chemical Etching

scholarly journals In Situ Synthesis of Core-Shell-Structured SiCp Reinforcements in Aluminium Matrix Composites by Powder Metallurgy

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1201
Author(s):  
Xinghua Ji ◽  
Cheng Zhang ◽  
Shufeng Li
Keyword(s):  
Particle Size ◽  
Powder Metallurgy ◽  
Shell Structure ◽  
Ex Situ ◽  
Aluminium Matrix ◽  
Core Shell ◽  
Matrix Composites ◽  
Aluminium Matrix Composites ◽  
Core Shell Structure

SiCp reinforced aluminium matrix composites (AMCs), which are widely used in the aerospace, automotive, and electronic packaging fields along with others, are usually prepared by ex situ techniques. However, interfacial contamination and poor wettability of the ex situ techniques make further improvement in their comprehensive performance difficult. In this paper, SiCp reinforced AMCs with theoretical volume fractions of 15, 20, and 30% are prepared by powder metallurgy and in situ reaction via an Al-Si-C system. Moreover, a combined method of external addition and an in situ method is used to investigate the synergistic effect of ex situ and in situ SiCp on AMCs. SiC particles can be formed by an indirect reaction: 4Al + 3C → Al4C3 and Al4C3 + 3Si → 3SiC + 4Al. This reaction is mainly through the diffusion of Si, in which Si diffuses around Al4C3 and then reacts with Al4C3 to form SiCp. The in situ SiC particles have a smooth boundary, and the particle size is approximately 1–3 μm. A core-shell structure having good bonding with an aluminium matrix was generated, which consists of an ex situ SiC core and an in situ SiC shell with a thickness of 1–5 μm. The yield strength and ultimate tensile strength of in situ SiCp reinforced AMCs can be significantly increased with a constant ductility by adding 5% ex situ SiCp for Al-28Si-7C. The graphite particle size has a significant effect on the properties of the alloy. A criterion to determine whether Al4C3 is a complete reaction is achieved, and the forming mechanism of the core-shell structure is analysed.

scholarly journals Removal of Cd(II) from Micro-Polluted Water by Magnetic Core-Shell Fe3O4@Prussian Blue

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2497
Author(s):  
Xinxin Long ◽  
Huanyu Chen ◽  
Tijun Huang ◽  
Yajing Zhang ◽  
Yifeng Lu ◽  
...  
Keyword(s):  
Prussian Blue ◽  
Co Adsorption ◽  
Magnetic Core ◽  
Diameter Distribution ◽  
Polluted Water ◽  
Core Shell ◽  
Freundlich Model ◽  
Rate Limiting Step ◽  
Rate Limiting

A novel core-shell magnetic Prussian blue-coated Fe3O4 composites (Fe3O4@PB) were designed and synthesized by in-situ replication and controlled etching of iron oxide (Fe3O4) to eliminate Cd (II) from micro-polluted water. The core-shell structure was confirmed by TEM, and the composites were characterized by XRD and FTIR. The pore diameter distribution from BET measurement revealed the micropore-dominated structure of Fe3O4@PB. The effects of adsorbents dosage, pH, and co-existing ions were investigated. Batch results revealed that the Cd (II) adsorption was very fast initially and reached equilibrium after 4 h. A pH of 6 was favorable for Cd (II) adsorption on Fe3O4@PB. The adsorption rate reached 98.78% at an initial Cd (II) concentration of 100 μg/L. The adsorption kinetics indicated that the pseudo-first-order and Elovich models could best describe the Cd (II) adsorption onto Fe3O4@PB, indicating that the sorption of Cd (II) ions on the binding sites of Fe3O4@PB was the main rate-limiting step of adsorption. The adsorption isotherm well fitted the Freundlich model with a maximum capacity of 9.25 mg·g−1 of Cd (II). The adsorption of Cd (II) on the Fe3O4@PB was affected by co-existing ions, including Cu (II), Ni (II), and Zn (II), due to the competitive effect of the co-adsorption of Cd (II) with other co-existing ions.

Sign in / Sign up

Export Citation Format

Share Document