A facile strategy to synthesize graphitic carbon-encapsulated core-shell nanocomposites derived from CO2 as functional materials

2020 ◽  
Vol 22 ◽  
pp. 100464
Author(s):  
Rui Yu ◽  
Bowen Deng ◽  
Kaiyuan Zheng ◽  
Xingyi Wang ◽  
Kaifa Du ◽  
...  
Keyword(s):  
Functional Materials ◽  
Graphitic Carbon ◽  
Core Shell

scholarly journals Iron Based Core-Shell Structures as Versatile Materials: Magnetic Support and Solid Catalyst

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 72
Author(s):  
Christian Zambrzycki ◽  
Runbang Shao ◽  
Archismita Misra ◽  
Carsten Streb ◽  
Ulrich Herr ◽  
...  
Keyword(s):  
Water Purification ◽  
Functional Materials ◽  
Core Material ◽  
Solid Catalyst ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Shell Nanostructures ◽  
Sio2 Shell ◽  
Iron Based

Core-shell materials are promising functional materials for fundamental research and industrial application, as their properties can be adapted for specific applications. In particular, particles featuring iron or iron oxide as core material are relevant since they combine magnetic and catalytic properties. The addition of an SiO2 shell around the core particles introduces additional design aspects, such as a pore structure and surface functionalization. Herein, we describe the synthesis and application of iron-based core-shell nanoparticles for two different fields of research that is heterogeneous catalysis and water purification. The iron-based core shell materials were characterized by transmission electron microscopy, as well as N2-physisorption, X-ray diffraction, and vibrating-sample magnetometer measurements in order to correlate their properties with the performance in the target applications. Investigations of these materials in CO2 hydrogenation and water purification show their versatility and applicability in different fields of research and application, after suitable individual functionalization of the core-shell precursor. For design and application of magnetically separable particles, the SiO2 shell is surface-functionalized with an ionic liquid in order to bind water pollutants selectively. The core requires no functionalization, as it provides suitable magnetic properties in the as-made state. For catalytic application in synthesis gas reactions, the SiO2-stabilized core nanoparticles are reductively functionalized to provide the catalytically active metallic iron sites. Therefore, Fe@SiO2 core-shell nanostructures are shown to provide platform materials for various fields of application, after a specific functionalization.

scholarly journals Amyloid fibril-directed synthesis of silica core–shell nanofilaments, gels, and aerogels

2019 ◽  
Vol 116 (10) ◽  
pp. 4012-4017 ◽  
Author(s):  
Yiping Cao ◽  
Sreenath Bolisetty ◽  
Gianna Wolfisberg ◽  
Jozef Adamcik ◽  
Raffaele Mezzenga
Keyword(s):  
Amyloid Fibril ◽  
Functional Materials ◽  
Building Blocks ◽  
Inorganic Materials ◽  
Core Shell ◽  
Shear Stresses ◽  
Bending Rigidity ◽  
Widespread Application ◽  
Nonmonotonic Dependence ◽  
Silica Core

Amyloid fibrils have evolved from purely pathological materials implicated in neurodegenerative diseases to efficient templates for last-generation functional materials and nanotechnologies. Due to their high intrinsic stiffness and extreme aspect ratio, amyloid fibril hydrogels can serve as ideal building blocks for material design and synthesis. Yet, in these gels, stiffness is generally not paired by toughness, and their fragile nature hinders significantly their widespread application. Here we introduce an amyloid-assisted biosilicification process, which leads to the formation of silicified nanofibrils (fibril–silica core–shell nanofilaments) with stiffness up to and beyond ∼20 GPa, approaching the Young’s moduli of many metal alloys and inorganic materials. The silica shell endows the silicified fibrils with large bending rigidity, reflected in hydrogels with elasticity three orders of magnitude beyond conventional amyloid fibril hydrogels. A constitutive theoretical model is proposed that, despite its simplicity, quantitatively interprets the nonmonotonic dependence of the gel elasticity upon the filaments bundling promoted by shear stresses. The application of these hybrid silica–amyloid hydrogels is demonstrated on the fabrication of mechanically stable aerogels generated via sequential solvent exchange, supercriticalCO2removal, and calcination of the amyloid core, leading to aerogels of specific surface area as high as 993m2/g, among the highest values ever reported for aerogels. We finally show that the scope of amyloid hydrogels can be expanded considerably by generating double networks of amyloid and hydrophilic polymers, which combine excellent stiffness and toughness beyond those of each of the constitutive individual networks.

Supporting Cu@In2O3 Core-Shell Structure on N-Doped Graphitic Carbon Cuboctahedra Cages for Efficient Photocatalytic Homo-Coupling of Terminal Alkynes

2021 ◽  
Author(s):  
Yaya Yuan ◽  
Yaqun Wang ◽  
Gui-lin Zhuang ◽  
Fenglei Yang ◽  
Qiu-Yan Li ◽  
...  
Keyword(s):  
Shell Structure ◽  
Active Sites ◽  
Separation Efficiency ◽  
Graphitic Carbon ◽  
Special Structure ◽  
Core Shell ◽  
Terminal Alkynes ◽  
Photocatalytic Efficiency ◽  
Core Shell Structure

Improving the separation efficiency of photogenerated carriers and exposing more active sites are two important factors to improve photocatalytic efficiency of photocatalyst. Designing appropriate materials with special structure and composition...

Manipulation of 2D carbon nanoplates with a core–shell structure for high-performance potassium-ion batteries

2019 ◽  
Vol 7 (34) ◽  
pp. 19929-19938 ◽  
Author(s):  
Dongjun Li ◽  
Xiaolong Cheng ◽  
Rui Xu ◽  
Ying Wu ◽  
Xuefeng Zhou ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Shell Structure ◽  
High Performance ◽  
Potassium Ion ◽  
Graphitic Carbon ◽  
Core Shell ◽  
Core Shell Structure

Quasi-2D core–shell amorphous carbon/graphitic carbon nanoplates (AC@GC) are designed, and they exhibit synergistic properties that enable the construction of superior K-ion batteries.

From helical nanowires, nanocrosses to aligned micro-carbon fibers

2003 ◽  
Vol 776 ◽  
Author(s):  
Hai-Feng Zhang ◽  
Chong-Min Wang ◽  
James S. Young ◽  
James E. Coleman ◽  
Lai-Sheng Wang
Keyword(s):  
Carbon Fibers ◽  
Chemical Vapor ◽  
Graphitic Carbon ◽  
Core Shell ◽  
Uniform Layer ◽  
C Fibers ◽  
Novel Structure ◽  
Vapor Deposition Technique ◽  
Potential Applications ◽  
Structural Characterizations

AbstractWe successfully synthesized helical core-shell crystalline SiC/SiO2 nanowires, core-shell crystalline SiC/C nano-crosses and well-aligned core-shell crystalline SiC/C fibers by using a chemical vapor deposition technique. For the helical crystalline SiC/SiO2 nanowires, the SiC core typically has diameters of 10-40 nm with a helical periodicity of 40-80 nm and is covered by a uniform layer of 30-60 nm thick amorphous SiO2. Detailed structural characterizations suggested that the growth of this novel structure was induced by screw dislocations on the nanometer scale. For the core-shell nanocrosses, the crystalline SiC core typically has diameters of 10 to 40 nm and is covered by a uniform layer of 80-110 nm graphitic carbon. The wellaligned SiC/C fibers were shown to be formed by two sequential steps: catalytic SiC growth and graphitic carbon nano-sheets coating. The helical nanowires and core-shell nanocrosses may have potential applications in nano-electronics. The formation mechanism of the carbon fibers suggested that fabrication of field emission filament carbon nano-fibers may be realized by using the aligned crystalline nanowires as templates.

scholarly journals Core/Shell Structure of Mesoporous Carbon Spheres and g-C3N4 for Acid Red 18 Decolorization

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1007
Author(s):  
Martyna Baca ◽  
Małgorzata Aleksandrzak ◽  
Ewa Mijowska ◽  
Ryszard J. Kaleńczuk ◽  
Beata Zielińska
Keyword(s):  
Shell Structure ◽  
Mesoporous Carbon ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Light Irradiation ◽  
Graphitic Carbon Nitride ◽  
Solar Light ◽  
Core Shell ◽  
Solar Light Irradiation ◽  
Core Shell Structure

Spherical photocatalyst based on ordered mesoporous carbon and graphitic carbon nitride with core/shell structure (CS/GCN) was successfully synthesized via facile electrostatic self-assembly strategy. The photocatalytic properties of the hybrid were evaluated by the decomposition of Acid Red 18 under simulated solar light irradiation in comparison to the bulk graphitic carbon nitride (GCN). The results clearly revealed that coupling of carbon nitride with mesoporous carbon allows the catalyst to form with superior photocatalytic performance. The photoactivity of CS/GCN was over nine times higher than that of pristine GCN. Introducing mesoporous carbon into GCN induced higher surface area of the heterojunction and also facilitated the contact surface between the two phases. The synergistic effect between those two components enhanced the visible light-harvesting efficiency and improved photoinduced charge carrier generation, and consequently their proper separation. The electrochemical behavior of the obtained composite was also evaluated by electrochemical impedance, transient photocurrent response and linear sweep potentiometry measurements. The results confirmed that transport and separation of charge carriers in the hybrid was enhanced in comparison to the reference bulk graphitic carbon nitride. Detailed electrochemical, photoluminescence and radical scavenger tests enabled determination of the possible mechanism of photocatalytic process. This work presents new insights to design a core/shell hybrid through the simple preparation process, which can be successfully used as an efficient photocatalyst for the treatment of wastewater containing dyes under solar light irradiation.

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