scholarly journals Hypergolic Synthesis of Inorganic Materials by the Reaction of Metallocene Dichlorides with Fuming Nitric Acid at Ambient Conditions: The Case of Photocatalytic Titania

Sci ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 46
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Athanasios B. Bourlinos ◽  
Michael A. Karakassides ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Materials Science ◽  
Organometallic Compounds ◽  
Inorganic Materials ◽  
Titania Nanoparticles ◽  
Titanocene Dichloride ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Wide Range ◽  
Fuming Nitric Acid

Hypergolic materials synthesis is a new preparative technique in materials science that allows a wide range of carbon or inorganic solids with useful properties to be obtained. Previously we have demonstrated that metallocenes are versatile reagents in the hypergolic synthesis of inorganic materials, such as γ-Fe2O3, Cr2O3, Co, Ni and alloy CoNi. Here, we go one step further by using metallocene dichlorides as precursors for the hypergolic synthesis of additional inorganic phases, such as photocatalytic titania. Metallocene dichlorides are closely related to metallocenes, thus expanding the arsenal of organometallic compounds that can be used in hypergolic materials synthesis. In the present case, we show that hypergolic ignition of the titanocene dichloride–fuming nitric acid pair results in the fast and spontaneous formation of titania nanoparticles at ambient conditions in the form of anatase–rutile mixed phases. The obtained titania shows good photocatalytic activity towards Cr(VI) removal (100% within 9 h), with the latter being dramatically enhanced after calcination of the powder at 500 °C (100% within 3 h). Notably, this performance was found to be comparable to that of commercially available P25 TiO2 under identical conditions. The cases of zirconocene, hafnocene and molybdocene dichlorides are discussed in this work, which aims to show the wider applicability of metallocene dichlorides in the hypergolic synthesis of inorganic materials (ZrO2, HfO2, MoO2).

scholarly journals Hypergolic Synthesis of Inorganic Materials by the Reaction of Metallocene Dichlorides With Fuming Nitric Acid At Ambient Conditions: The Case of Photocatalytic Titania

2021 ◽  
Author(s):  
Nikolaos Chalmpes ◽  
Georgios Asimakopoulos ◽  
Maria Baikousi ◽  
Athanasios B. Bourlinos ◽  
Michael A. Karakassides ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Materials Science ◽  
Organometallic Compounds ◽  
Inorganic Materials ◽  
Titania Nanoparticles ◽  
Titanocene Dichloride ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Wide Range ◽  
Fuming Nitric Acid

Hypergolic materials synthesis is a new preparative technique in materials science that allows a wide range of carbon or inorganic solids with useful properties to be obtained. Previously we have demonstrated that metallocenes are versatile reagents in the hypergolic synthesis of inorganic materials, such as γ-Fe2O3, Cr2O3, Co, Ni and alloy CoNi. Here, we take one step further by using metallocene dichlorides as precursors for the hypergolic synthesis of additional inorganic phases, such as photocatalytic titania. Metallocene dichlorides are closely related to metallocenes, thus expanding the arsenal of organometallic compounds that can be used in hypergolic materials synthesis. In the present case, we show that hypergolic ignition of the titanocene dichloride-fuming nitric acid pair results in the fast and spontaneous formation of titania nanoparticles at ambient conditions in the form of anatase-rutile mixed phases. The obtained titania shows good photocatalytic activity towards Cr(VI) removal (100 % within 9 h), the latter being dramatically enhanced after calcination of the powder at 500 °C (100 % within 3 h). Worth noting, this performance was found to be comparable to that of commercially available P25 TiO2 under identical conditions. The cases of zirconocene, hafnocene and molybdocene dichlorides are complementary discussed in this work, aiming to show the wider applicability of metallocene dichlorides in the hypergolic synthesis of inorganic materials (ZrO2, HfO2, MoO2).

scholarly journals Nanocarbon from Rocket Fuel Waste: The Case of Furfuryl Alcohol-Fuming Nitric Acid Hypergolic Pair

Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 1
Author(s):  
Nikolaos Chalmpes ◽  
Athanasios B. Bourlinos ◽  
Smita Talande ◽  
Aristides Bakandritsos ◽  
Dimitrios Moschovas ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Furfuryl Alcohol ◽  
Materials Science ◽  
Ambient Conditions ◽  
Materials Synthesis ◽  
Rocket Fuel ◽  
Carbon Nanosheets ◽  
New Synthesis ◽  
Fuming Nitric Acid ◽  
Liquid Rocket

In hypergolics two substances ignite spontaneously upon contact without external aid. Although the concept mostly applies to rocket fuels and propellants, it is only recently that hypergolics has been recognized from our group as a radically new methodology towards carbon materials synthesis. Comparatively to other preparative methods, hypergolics allows the rapid and spontaneous formation of carbon at ambient conditions in an exothermic manner (e.g., the method releases both carbon and energy at room temperature and atmospheric pressure). In an effort to further build upon the idea of hypergolic synthesis, herein we exploit a classic liquid rocket bipropellant composed of furfuryl alcohol and fuming nitric acid to prepare carbon nanosheets by simply mixing the two reagents at ambient conditions. Furfuryl alcohol served as the carbon source while fuming nitric acid as a strong oxidizer. On ignition the temperature is raised high enough to induce carbonization in a sort of in-situ pyrolytic process. Simultaneously, the released energy was directly converted into useful work, such as heating a liquid to boiling or placing Crookes radiometer into motion. Apart from its value as a new synthesis approach in materials science, carbon from rocket fuel additionally provides a practical way in processing rocket fuel waste or disposed rocket fuels.

scholarly journals Hypergolic Materials Synthesis through Reaction of Fuming Nitric Acid with Certain Cyclopentadienyl Compounds

2020 ◽  
Vol 6 (4) ◽  
pp. 61 ◽  
Author(s):  
Nikolaos Chalmpes ◽  
Athanasios B. Bourlinos ◽  
Veronika Šedajová ◽  
Vojtěch Kupka ◽  
Dimitrios Moschovas ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Organometallic Chemistry ◽  
Carbon Materials ◽  
Materials Science ◽  
Inorganic Materials ◽  
Materials Synthesis ◽  
Fuming Nitric Acid

Recently we have shown the importance of hypergolic reactions in carbon materials synthesis. However, hypergolic reactions could be certainly expanded beyond carbon synthesis, offering a general preparative pathway towards a larger variety of materials. Cyclopentadienyls are one of the most common ligands in organometallic chemistry that react hypergolicly on contact with strong oxidizers. By also considering the plethora of cyclopentadienyl compounds existing today, herein we demonstrate the potential of such compounds in hypergolic materials synthesis in general (carbon or inorganic). In a first example, we show that cyclopentadienyllithium reacts hypergolicly with fuming nitric acid to produce carbon. In a second one, we show that ferrocene and cobaltocene also react hypergolicly with the concentrated acid to afford magnetic inorganic materials, such as γ-Fe2O3 and metallic Co, respectively. The present results further emphasize the importance and universal character of hypergolic reactions in materials science synthesis, as an interesting new alternative to other existing and well-established preparative methods.

scholarly journals Bio-Templating: An Emerging Synthetic Technique for Catalysts. A Review

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1364
Author(s):  
M. Carmen Herrera-Beurnio ◽  
Jesús Hidalgo-Carrillo ◽  
Francisco J. López-Tenllado ◽  
Juan Martin-Gómez ◽  
Rafael C. Estévez ◽  
...  
Keyword(s):  
Active Sites ◽  
Experimental Studies ◽  
Functional Materials ◽  
Inorganic Materials ◽  
Hierarchical Organization ◽  
Materials Synthesis ◽  
Energy Capture ◽  
Wide Range ◽  
Mineralization Processes ◽  
And Storage

In the last few years, researchers have focused their attention on the synthesis of new catalyst structures based on or inspired by nature. Biotemplating involves the transfer of biological structures to inorganic materials through artificial mineralization processes. This approach offers the main advantage of allowing morphological control of the product, as a template with the desired morphology can be pre-determined, as long as it is found in nature. This way, natural evolution through millions of years can provide us with new synthetic pathways to develop some novel functional materials with advantageous properties, such as sophistication, miniaturization, hybridization, hierarchical organization, resistance, and adaptability to the required need. The field of application of these materials is very wide, covering nanomedicine, energy capture and storage, sensors, biocompatible materials, adsorbents, and catalysis. In the latter case, bio-inspired materials can be applied as catalysts requiring different types of active sites (i.e., redox, acidic, basic sites, or a combination of them) to a wide range of processes, including conventional thermal catalysis, photocatalysis, or electrocatalysis, among others. This review aims to cover current experimental studies in the field of biotemplating materials synthesis and their characterization, focusing on their application in heterogeneous catalysis.

NanoSIMS Imaging and Analysis in Materials Science

2020 ◽  
Vol 13 (1) ◽  
pp. 273-292 ◽  
Author(s):  
Kexue Li ◽  
Junliang Liu ◽  
Chris R.M. Grovenor ◽  
Katie L. Moore
Keyword(s):  
Materials Science ◽  
Boundary Segregation ◽  
Chemical Imaging ◽  
Inorganic Materials ◽  
Light Elements ◽  
Efficient Detection ◽  
Good Spatial Resolution ◽  
Wide Range ◽  
Nanosims Analysis ◽  
Oil Gas

High-resolution SIMS analysis can be used to explore a wide range of problems in material science and engineering materials, especially when chemical imaging with good spatial resolution (50–100 nm) can be combined with efficient detection of light elements and precise separation of isotopes and isobaric species. Here, applications of the NanoSIMS instrument in the analysis of inorganic materials are reviewed, focusing on areas of current interest in the development of new materials and degradation mechanisms under service conditions. We have chosen examples illustrating NanoSIMS analysis of grain boundary segregation, chemical processes in cracking, and corrosion of nuclear components. An area where NanoSIMS analysis shows potential is in the localization of light elements, in particular, hydrogen and deuterium. Hydrogen embrittlement is a serious problem for industries where safety is critical, including aerospace, nuclear, and oil/gas, so it is imperative to know where in the microstructure hydrogen is located. By charging the metal with deuterium, to avoid uncertainty in the origin of the hydrogen, the microstructural features that can trap hydrogenic species, such as precipitates and grain and phase boundaries, can be determined by NanoSIMS analysis on a microstructurally relevant scale.

scholarly journals A versatile nanoreactor for complementary in situ X-ray and electron microscopy studies in catalysis and materials science

2019 ◽  
Vol 26 (5) ◽  
pp. 1769-1781 ◽  
Author(s):  
Yakub Fam ◽  
Thomas L. Sheppard ◽  
Johannes Becher ◽  
Dennis Scherhaufer ◽  
Heinz Lambach ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Materials Science ◽  
Functional Materials ◽  
Ambient Conditions ◽  
Zeolite Sample ◽  
X Ray ◽  
Fluorescence Measurements ◽  
Wide Range ◽  
Modular Platform

Two in situ `nanoreactors' for high-resolution imaging of catalysts have been designed and applied at the hard X-ray nanoprobe endstation at beamline P06 of the PETRA III synchrotron radiation source. The reactors house samples supported on commercial MEMS chips, and were applied for complementary hard X-ray ptychography (23 nm spatial resolution) and transmission electron microscopy, with additional X-ray fluorescence measurements. The reactors allow pressures of 100 kPa and temperatures of up to 1573 K, offering a wide range of conditions relevant for catalysis. Ptychographic tomography was demonstrated at limited tilting angles of at least ±35° within the reactors and ±65° on the naked sample holders. Two case studies were selected to demonstrate the functionality of the reactors: (i) annealing of hierarchical nanoporous gold up to 923 K under inert He environment and (ii) acquisition of a ptychographic projection series at ±35° of a hierarchically structured macroporous zeolite sample under ambient conditions. The reactors are shown to be a flexible and modular platform for in situ studies in catalysis and materials science which may be adapted for a range of sample and experiment types, opening new characterization pathways in correlative multimodal in situ analysis of functional materials at work. The cells will presently be made available for all interested users of beamline P06 at PETRA III.

scholarly journals Hypergolic Ignition of 1,3-Cyclodienes by Fuming Nitric Acid toward the Fast and Spontaneous Formation of Carbon Nanosheets at Ambient Conditions

Micro ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 15-27
Author(s):  
Nikolaos Chalmpes ◽  
Dimitrios Moschovas ◽  
Athanasios B. Bourlinos ◽  
Konstantinos Spyrou ◽  
Konstantinos C. Vasilopoulos ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Carbon Nanostructures ◽  
Carbon Matrix ◽  
Preparative Method ◽  
Expandable Graphite ◽  
Ambient Conditions ◽  
Organic Fuel ◽  
Carbon Nanosheets ◽  
Organic Fuels ◽  
Fuming Nitric Acid

A hypergolic system is a combination of organic fuel and oxidizer that ignites spontaneously upon contact without any external ignition source. Although their main usage pertains to rocket bipropellants, it is only recently that hypergolics have been established from our group as a revolutionary preparative method for the synthesis of different types of carbon nanostructures depending on the organic fuel-oxidizer pair. In an effort to further enrich this concept, the present work describes new hypergolic pairs based on 1,3-cyclohexadiene and 1,3-cyclooctadiene as the organic fuels and fuming nitric acid as the strong oxidizer. Both carbon-rich compounds (ca. 90% C) share a similar chemical structure with unsaturated cyclopentadiene that is also known to react hypergolically with fuming nitric acid. The particular pairs ignite spontaneously upon contact of the reagents at ambient conditions to produce carbon nanosheets in suitable yields and useful energy in the process. The nanosheets appear amorphous with an average thickness of ca. 2 nm and containing O and N heteroatoms in the carbon matrix. Worth noting, the carbon yield reaches the value of 25% for 1,3-cyclooctadiene, i.e., the highest reported so far from our group in this context. As far as the production of useful energy is concerned, the hot flame produced from ignition can be used for the direct thermal decomposition of ammonium dichromate into Cr2O3 (pigment and catalyst) or the expansion of expandable graphite into foam (absorbent and insulator), thus demonstrating a mini flame-pyrolysis burner at the spot.

scholarly journals Carbon Nanostructures Derived through Hypergolic Reaction of Conductive Polymers with Fuming Nitric Acid at Ambient Conditions

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1595
Author(s):  
Nikolaos Chalmpes ◽  
Dimitrios Moschovas ◽  
Iosif Tantis ◽  
Athanasios B. Bourlinos ◽  
Aristides Bakandritsos ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Carbon Nanostructures ◽  
Carbon Nanomaterials ◽  
Conductive Polymers ◽  
Ambient Conditions ◽  
Organic Fuel ◽  
Carbon Nanosheets ◽  
New Synthesis ◽  
New Type ◽  
Fuming Nitric Acid

Hypergolic systems rely on organic fuel and a powerful oxidizer that spontaneously ignites upon contact without any external ignition source. Although their main utilization pertains to rocket fuels and propellants, it is only recently that hypergolics has been established from our group as a new general method for the synthesis of different morphologies of carbon nanostructures depending on the hypergolic pair (organic fuel-oxidizer). In search of new pairs, the hypergolic mixture described here contains polyaniline as the organic source of carbon and fuming nitric acid as strong oxidizer. Specifically, the two reagents react rapidly and spontaneously upon contact at ambient conditions to afford carbon nanosheets. Further liquid-phase exfoliation of the nanosheets in dimethylformamide results in dispersed single layers exhibiting strong Tyndall effect. The method can be extended to other conductive polymers, such as polythiophene and polypyrrole, leading to the formation of different type carbon nanostructures (e.g., photolumincent carbon dots). Apart from being a new synthesis pathway towards carbon nanomaterials and a new type of reaction for conductive polymers, the present hypergolic pairs also provide a novel set of rocket bipropellants based on conductive polymers.

scholarly journals Six-membered-ring inorganic materials: definition and prospects

2020 ◽  
Author(s):  
Gang Liu ◽  
Xing-Qiu Chen ◽  
Bilu Liu ◽  
Wencai Ren ◽  
Hui-Ming Cheng
Keyword(s):  
Materials Science ◽  
Transition Metal Dichalcogenides ◽  
Three Dimensional ◽  
Membered Ring ◽  
Inorganic Materials ◽  
Common Structure ◽  
Wide Range ◽  
Materials Research ◽  
Metal Dichalcogenides ◽  
New Perspective

Abstract The six-membered ring (SMR) is a common structure unit for numerous material systems. These materials include, but are not limited to, the typical two-dimensional materials such as graphene, h-BN, and transition metal dichalcogenides, as well as three-dimensional materials such as beryllium, magnesium, MgB2, and Bi2Se3. Although many of these materials have already become ‘stars’ in materials science and condensed-matter physics, little attention has been paid to the roles of their SMR unit across a wide range of compositions and structures. In this article, we systematically analyze these materials with respect to their very basic SMR structural unit, which has been found to play a deterministic role in the occurrence of many intriguing properties and phenomena, such as Dirac electronic and phononic spectra, superconductivity and topology. As a result, we have defined this group of materials as SMR inorganic materials, which opens a new perspective on materials research and development. With their unique properties, SMR materials deserve wide attention and in-depth investigation from materials design, new physical discoveries to target-wizard applications. It is expected that SMR materials will find niche applications in next-generation information technology, renewable energy, space, etc.

Bio-based approaches to inorganic material synthesis

2007 ◽  
Vol 35 (3) ◽  
pp. 512-515 ◽  
Author(s):  
M.M. Tomczak ◽  
J.M. Slocik ◽  
M.O. Stone ◽  
R.R. Naik
Keyword(s):  
Inorganic Material ◽  
Materials Science ◽  
High Heat ◽  
Marine Sponges ◽  
Inorganic Materials ◽  
Ambient Conditions ◽  
Material Synthesis ◽  
Wall Structures ◽  
Nanoparticle Morphology ◽  
Silica Wall

Nature is an exquisite designer of inorganic materials using biomolecules as templates. Diatoms create intricate silica wall structures with fine features using the protein family of silaffins as templates. Marine sponges create silica spicules also using proteins, termed silicateins. In recent years, our group and others have used biomolecules as templates for the deposition of inorganic materials. In contrast with the traditional materials science approach, which requires high heat, extreme pH and non-aqueous solutions, the bio-based approaches allow the reactions to proceed usually at near ambient conditions. Additionally, the biological templates allow for the control of the inorganic nanoparticle morphology. The use of peptides and biomolecules for templating and assembling inorganics will be discussed here.

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