Toward the control of graphenic foams

2017 ◽  
Vol 89 (4) ◽  
pp. 565-577 ◽  
Author(s):  
Lucie Speyer ◽  
Océane Louppe ◽  
Sébastien Fontana ◽  
Sébastien Cahen ◽  
Claire Hérold
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Solvothermal Reaction ◽  
Synthesis Methods ◽  
Structure And Properties ◽  
Optimal Conditions ◽  
Experimental Conditions ◽  
Wide Range

AbstractGraphene-based materials are extensively studied, due to their excellent properties and their wide range of possible applications. Attention has recently been paid to three-dimensional-like graphenic structures, such as crumpled graphene sheets and graphenic foams: these kinds of materials can combine the properties of graphene associating high surface area and porosity, what is particularly interesting for energy or catalysis applications. Most of the synthesis methods leading to such structures are based on graphite oxide exfoliation and re-assembly, but in this work we focus on the preparation of graphenic foams by a solvothermal-based process. We performed a solvothermal reaction between ethanol and sodium at 220°C, during 72 h, under 200 bar, followed by a pyrolysis under nitrogen flow. An extended study of the influence of the temperature (800°C–900°C) of pyrolysis evidences an unexpected strong effect of this parameter on the characteristics of the materials. The optimal conditions provide multi-layer graphene (10 layers) foam with a surface area of 2000 m2·g−1. This work is an important step for the understanding of the mechanisms of the thermal treatment. Post-treatments in different experimental conditions are performed in order to modulate the structure and properties of the graphenic foams.

scholarly journals Methods for tuning plasmonic and photonic optical resonances in high surface area porous electrodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lauren M. Otto ◽  
E. Ashley Gaulding ◽  
Christopher T. Chen ◽  
Tevye R. Kuykendall ◽  
Aeron T. Hammack ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystals ◽  
Titanium Nitride ◽  
Surface Area ◽  
Periodic Structures ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Porous Electrodes ◽  
Wide Range

AbstractSurface plasmons have found a wide range of applications in plasmonic and nanophotonic devices. The combination of plasmonics with three-dimensional photonic crystals has enormous potential for the efficient localization of light in high surface area photoelectrodes. However, the metals traditionally used for plasmonics are difficult to form into three-dimensional periodic structures and have limited optical penetration depth at operational frequencies, which limits their use in nanofabricated photonic crystal devices. The recent decade has seen an expansion of the plasmonic material portfolio into conducting ceramics, driven by their potential for improved stability, and their conformal growth via atomic layer deposition has been established. In this work, we have created three-dimensional photonic crystals with an ultrathin plasmonic titanium nitride coating that preserves photonic activity. Plasmonic titanium nitride enhances optical fields within the photonic electrode while maintaining sufficient light penetration. Additionally, we show that post-growth annealing can tune the plasmonic resonance of titanium nitride to overlap with the photonic resonance, potentially enabling coupled-phenomena applications for these three-dimensional nanophotonic systems. Through characterization of the tuning knobs of bead size, deposition temperature and cycle count, and annealing conditions, we can create an electrically- and plasmonically-active photonic crystal as-desired for a particular application of choice.

scholarly journals Salt-Mediated Au-Cu Nanofoam and Au-Cu-Pd Porous Macrobeam Synthesis

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1701 ◽  
Author(s):  
Fred Burpo ◽  
Enoch Nagelli ◽  
Lauren Morris ◽  
Kamil Woronowicz ◽  
Alexander Mitropoulos
Keyword(s):  
Surface Area ◽  
Electrochemical Impedance ◽  
High Surface ◽  
Electronic Conductivity ◽  
High Surface Area ◽  
Three Dimensional ◽  
Synthesis Methods ◽  
X Ray ◽  
Sensing Applications ◽  
Metal Composition

Multi-metallic and alloy nanomaterials enable a broad range of catalytic applications with high surface area and tuning reaction specificity through the variation of metal composition. The ability to synthesize these materials as three-dimensional nanostructures enables control of surface area, pore size and mass transfer properties, electronic conductivity, and ultimately device integration. Au-Cu nanomaterials offer tunable optical and catalytic properties at reduced material cost. The synthesis methods for Au-Cu nanostructures, especially three-dimensional materials, has been limited. Here, we present Au-Cu nanofoams and Au-Cu-Pd macrobeams synthesized from salt precursors. Salt precursors formed from the precipitation of square planar ions resulted in short- and long-range ordered crystals that, when reduced in solution, form nanofoams or macrobeams that can be dried or pressed into freestanding monoliths or films. Metal composition was determined with X-ray diffraction and energy dispersive X-ray spectroscopy. Nitrogen gas adsorption indicated an Au-Cu nanofoam specific surface area of 19.4 m2/g. Specific capacitance determined with electrochemical impedance spectroscopy was 46.0 F/g and 52.5 F/g for Au-Cu nanofoams and Au-Cu-Pd macrobeams, respectively. The use of salt precursors is envisioned as a synthesis route to numerous metal and multi-metallic nanostructures for catalytic, energy storage, and sensing applications.

scholarly journals Towards Control of the Size, Composition and Surface Area of NiO Nanostructures by Sn Doping

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 444
Author(s):  
María Taeño ◽  
David Maestre ◽  
Julio Ramírez-Castellanos ◽  
Shaohui Li ◽  
Pooi See Lee ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Size Composition ◽  
Charge Compensation ◽  
Potential Candidate ◽  
Sno2 Nanostructures ◽  
Experimental Conditions ◽  
Sn Doping ◽  
Compensation Mechanisms

Achieving nanostructures with high surface area is one of the most challenging tasks as this metric usually plays a key role in technological applications, such as energy storage, gas sensing or photocatalysis, fields in which NiO is gaining increasing attention recently. Furthermore, the advent of modern NiO-based devices can take advantage of a deeper knowledge of the doping process in NiO, and the fabrication of p-n heterojunctions. By controlling experimental conditions such as dopant concentration, reaction time, temperature or pH, NiO morphology and doping mechanisms can be modulated. In this work, undoped and Sn doped nanoparticles and NiO/SnO2 nanostructures with high surface areas were obtained as a result of Sn incorporation. We demonstrate that Sn incorporation leads to the formation of nanosticks morphology, not previously observed for undoped NiO, promoting p-n heterostructures. Consequently, a surface area value around 340 m2/g was obtained for NiO nanoparticles with 4.7 at.% of Sn, which is nearly nine times higher than that of undoped NiO. The presence of Sn with different oxidation states and variable Ni3+/Ni2+ ratio as a function of the Sn content were also verified by XPS, suggesting a combination of two charge compensation mechanisms (electronic and ionic) for the substitution of Ni2+ by Sn4+. These results make Sn doped NiO nanostructures a potential candidate for a high number of technological applications, in which implementations can be achieved in the form of NiO–SnO2 p-n heterostructures.

Hierarchical Nano/Micro-structured Surfaces with High Surface Area/Volume Ratios

2021 ◽  
pp. 1-36
Author(s):  
Ketki Lichade ◽  
Yizhou Jiang ◽  
Yayue Pan
Keyword(s):  
Surface Structure ◽  
Surface Area ◽  
Light Trapping ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Structure Design ◽  
Surface Structures ◽  
Structured Surfaces ◽  
Design And Manufacture

Abstract Recently, many studies have investigated additive manufacturing of hierarchical surfaces with high surface area/volume (SA/V) ratios, and their performance has been characterized for applications in next-generation functional devices. Despite recent advances, it remains challenging to design and manufacture high SA/V ratio structures with desired functionalities. In this study, we established the complex correlations among the SA/V ratio, surface structure geometry, functionality, and manufacturability in the Two-Photon Polymerization (TPP) process. Inspired by numerous natural structures, we proposed a 3-level hierarchical structure design along with the mathematical modeling of the SA/V ratio. Geometric and manufacturing constraints were modeled to create well-defined three-dimensional hierarchically structured surfaces with a high accuracy. A process flowchart was developed to design the proposed surface structures to achieve the target functionality, SA/V ratio, and geometric accuracy. Surfaces with varied SA/V ratios and hierarchy levels were designed and printed. The wettability and antireflection properties of the fabricated surfaces were characterized. It was observed that the wetting and antireflection properties of the 3-level design could be easily tailored by adjusting the design parameter settings and hierarchy levels. Furthermore, the proposed surface structure could change a naturally-hydrophilic surface to near-superhydrophobic. Geometrical light trapping effects were enabled and the antireflection property could be significantly enhanced (>80% less reflection) by the proposed hierarchical surface structures. Experimental results implied the great potential of the proposed surface structures for various applications such as microfluidics, optics, energy, and interfaces.

Three-Dimensional Cage Type Mesoporous CN-Based Hybrid Material with Very High Surface Area and Pore Volume

2007 ◽  
Vol 19 (17) ◽  
pp. 4367-4372 ◽  
Author(s):  
Ajayan Vinu ◽  
Pavuluri Srinivasu ◽  
Dhanashri P. Sawant ◽  
Toshiyuki Mori ◽  
Katsuhiko Ariga ◽  
...  
Keyword(s):  
Surface Area ◽  
Hybrid Material ◽  
Pore Volume ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Very High

Synthesis and characterization of mesalamine silica nanoparticles

2021 ◽  
Vol 16 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Ramya Krishna Nakkala ◽  
Prasanna Kumar Desu ◽  
Vikas Jhawat
Keyword(s):  
Particle Size ◽  
Silica Nanoparticles ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Silica Nanoparticle ◽  
Water Soluble ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Wide Range

Background: Nanoparticles made of silica are new materials that can be used in a wide range of drug delivery methods because they are biocompatible and biodegradable. Mesalamine, a classic water-soluble medication, remains loaded into the synthesized silica nanoparticle and is considered for sustained release proficiency. Precipitation approach using high surface area and pore volume tetraethyl orthosilicate yielded mesalamine-loaded silica nanoparticles. Methods: The drug-loaded nanoparticle was created and produced using two different techniques. Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, Brauer Emmett teller, scanning electron microscopy, particle size measurements, and dissolution investigations have all been used to analyse the substance in some way or another. Results: Because of the high surface area, well-known results like the complete silica nanoparticle created using method-2 remained mesoporous. The onset peak of the method-2 formulation's DSC was 182.27°c, and the offset peak was 192.14°c, consistent with the DSC results. The particle size range varies from 205-225nm. The results demonstrate that the uptake of the mesalamine by burst release it for 30 minutes initial, followed by sustained maintenance of dose even after 240 minutes. The results indicate that the loading process has an effect on the extent of loading. When silica nanoparticles were impregnated with mesalamine, the amount of the drug contained was significantly higher than when they were wetted. Conclusion: In addition, the XRD results show that both the pure mesalamine and the formulation did not show any polymorphic deviation.

New Advances in Graphene-Based Three-Dimensional Structures

2022 ◽  
pp. 101-128
Author(s):  
Javier Cencerrero Fernández del Moral ◽  
Amaya Romero Izquierdo ◽  
Paula Sánchez Paredes ◽  
Osmín Avilés-García ◽  
Israel Fernandez-Reina
Keyword(s):  
Surface Area ◽  
Environmental Remediation ◽  
Three Dimensional ◽  
Single Atom ◽  
Synthesis Methods ◽  
High Porosity ◽  
Covalent Bonds ◽  
Dimensional Network ◽  
Wide Range ◽  
Electron Transfer Properties

Graphene is defined as a two-dimensional network of carbon atoms with a single atom thickness and a hexagonal crystalline structure with sp2 hybridization compacted by covalent bonds. Due to its structure and geometry, graphene has unique properties, including a large specific surface area, rapid mobility of load carriers, and high thermal and electrical conductivity. However, these characteristics are limited due to the restructuring of graphene sheets. For this reason, there are many studies devoted to the synthesis of three-dimensional structures that prevent the agglomeration of the sheets and the loss of properties of the graphene structure. These three-dimensional structures have low density, high porosity and surface area, stable mechanical properties, and good mass and electron transfer properties. This chapter aims to summarize the synthesis methods of the different three-dimensional structures derived from graphene as well as their wide range of applications in environmental remediation, sensors, biomedical and energy-related applications, among many others.

Fabrication of Ultra-Low Density, High Surface Area Carbon Aerogels and their Application in Supercapacitors

2016 ◽  
Vol 852 ◽  
pp. 1349-1355
Author(s):  
Jia Yi Zhu ◽  
Xi Yang ◽  
Zhi Bing Fu ◽  
Chao Yang Wang ◽  
Wei Dong Wu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Carbon Aerogel ◽  
Carbon Aerogels ◽  
Low Density ◽  
Organic Aerogel ◽  
Cyclic Voltammetry Test

The ultra-low density carbon aerogel, as low as 20 mg/cm3, was fabricated by pyrolysis of the organic aerogel formed by aqueous condensation of resorcinol and formaldehyde. Its surface area was as high as 1783 m2/g and it was used for investigation of electrochemical capacitive behaviours. The ultra-low density carbon aerogel displayed capacitive performance (110 F/g at 0.2 A/g) in 6 M KOH aqueous solution. Additionally, over 98% of the initial capacitance was retained after repeating the cyclic voltammetry test for 1000 cycles. The electrochemical performance might be attributed to the combination of three dimensional “opened” structure and high surface area of the carbon aerogel.

Sign in / Sign up

Export Citation Format

Share Document