Christos Argirusis

National Technical University of Athens | NTUA · School of Chemical Engineering

A zinc-based Metal-Organic Framework (MOF) has been prepared by utilizing adipic acid as an aliphatic ditopic linker via both solvothermal and sonochemical methods. The ultrasound irradiation has reduced the reaction time and has led to smaller particle size. The samples were evaluated for their catalytic efficiency by the electrochemical reduction...

Metal-Organic Frameworks have attracted profound attention the latest years for use in environmental applications. They can offer a broad variety of functions due to their tunable porosity, high surface area and metal activity centers. Not more than ten years ago, they have been applied experimentally for the first time in energy storage devices, s...

Metal-air batteries (MABs) have received revived interest in the last decade for next-generation energy storage and conversion systems. Such batteries offer many prospects and advantages regarding high energy density, environmental friendliness, and low cost. However, their long lifetime and large-scale adoption are still inhibited by multiple fact...

The global energy crisis, fathomed by fossil fuel depletion and environmental issues, has shaped up the need for renewable energy sources and innovative energy storage devices. Tremendous efforts have been devoted to outpacing this aggressive consumption, reducing CO2 emissions, and introducing clean energy. Electrochemical energy storage and conve...

TiO2-based photocatalyst materials have been widely studied for the abatement of contaminants of emerging concerns (CECs) in water sources. In this study, 1.5 wt% Mo-doped HRTiO2 was obtained by the sonochemical method. The material was analyzed and characterized for thermal, structural/textural, morphological, and optical properties using TGA-DSC,...

The treatment of real waste extracts with simultaneous energy production is currently under research. One method of addressing this dual task is using biochemical reactors named microbial fuel cells (MFCs). MFCs consist of a bioanode and a cathode where the oxygen reduction reaction (ORR) occurs. Cathodes are currently under optimization regarding...

Zinc-air batteries (ZABs) are rising contenders for future applications in the power sources sector, due to their intrinsically elevated energy capacity coexisting with eco-friendly characteristics. Although rechargeable alkaline aqueous ZABs hold a considerable position in current research reports, their practical large-scale adoption is still obs...

The aim of this study is to examine the effect of food waste condensate concentration (400–4000 mg COD/L) on the performance of two microbial fuel cells (MFCs). Food waste condensate is produced after condensing the vapors that result from drying and shredding of household food waste (HFW). Two identical single-chamber MFCs were constructed with di...

Advanced oxidation procedures (AOPs) refer to a variety of technical procedures that produce OH radicals to sufficiently oxidize wastewater, organic pollutant streams, and toxic effluents from industrial, hospital, pharmaceutical and municipal wastes. Through the implementation of such procedures, the (post) treatment of such waste effluents leads...

The cathode electrode accommodates the oxidizing agent in conventional batteries, thus its characteristics actively determine the performance, cycle life, and environmental footprint of the battery. The key to rational fabrication of efficient cathodes nowadays is to directly associate the properties of materials used with current advanced battery...

The development of supercapacitors (SCs) has gained a lot of attention due to their unique properties, such as long cycle life and high-power density. The key component of SCs, in order to increase their efficiency and capacitance, is the porous electrode. This chapter introduces the use of MOF nanocomposites as alternative materials for SCs. MOFs...

Recent studies have found that the world is now producing over 2 billion tons of solid waste each year, with this number set to rise in the coming decades. Given the UN’s Sustainable Development Goals (SDGs), which aim to facilitate a peaceful and prosperous world, we need to consider how materials science research into recycling processes and wast...

This study reports on the investigation of the digestate treatment using microbial fuel cell (MFC) technology. The effluents from a thermophilic and a mesophilic anaerobic digester, fed with fermentable household food waste (FORBI), were characterized and used as the feed in four air–cathode MFC units. The chemical oxygen demand (COD) removal range...

Invitation to submit papers to special issue of Energies: hydrogen and syngas generation

In this work, a lytic polysaccharide monooxygenase (LPMO) belonging to the AA9 family from the filamentous fungus Thermothelomyces thermophilus, MtLPMO9H, is immobilized on cobalt functionalized multi-walled carbon nanotubes modified glassy carbon electrode. The step of the binding of phosphoric acid swollen cellulose on this LPMO is studied using...

New biotechnological processes using microorganisms and/or enzymes to convert carbonaceous resources, either biomass or depolymerized plastics into a broad range of different bioproducts are recognized for their high potential for reduced energy consumption and reduced GHG emissions. However, the hydrophobicity, high molecular weight, chemical and...

The electrochemical deposition and dissolution of Cu from chloride-based electrolyte was studied employing the electrochemical quartz crystal microbalance (EQCM)-coupled ultrasound technique. The ultrasound was generated using an ultrasonic horn probe, which was positioned in the face-on configuration at a different distance (8, 15, and 22 mm) from...

In the present work, ultrasound irradiation, photocatalysis with TiO2, Fenton/Photo-Fenton reaction, and the combination of those techniques were investigated for the decolorization of industrial dyes in order to study their synergy. Three azo dyes were selected from the weaving industry. Their degradation was examined via UV illumination, Fenton a...

Ultrasound (US) technology is already into the research field providing a powerful tool of producing nanomaterials or being implicated in decoration procedures of catalyst supports for energy applications and material production. Toward this concept, low or/and high-frequency USs are used for the production of nanoparticles, the decoration of catal...

Rhenium oxide nanoparticles have been prepared using ultrasonication at 20 kHz. Samples characterization was committed via SEM-EDX, TEM, XRD, and Raman spectroscopy. Various experimental parameters were examined, including precursor/substrate amounts, ultrasonication intensity, and type of solvent used. Insights to the agglomeration of the prepared...

The Guest Editors are inviting submissions to a Special Issue of Energies, titled “Hydrogen and Syngas Generation”.

This chapter introduces the sonochemical synthesis of metal organic frameworks (MOFs). The main purpose is to present an alternative way of preparing MOF crystals. State-of-the-art ultrasound-assisted techniques for the preparation of MOF nanoparticles are thoroughly discussed. Focusing on the optimization parameters, the chapter also draws attenti...

A lab-scale custom made Zinc-Air battery cell was manufactured and tested with a variety of cathode catalysts. MnO2 has been examined both as an Oxygen Reduction Reaction (ORR) and Oxygen Evolution Reaction (OER) catalyst, with more promising results as an ORR catalyst. MnO2 as well as a combination of MnO2 and MWCNTs (MOCN-10) has been examined in...

Sonochemistry was used for the metal oxides nanoparticle synthesis. All experiments were run using a BANDELIN Sonopuls HD 3200 ultrasonic generator (20 kHz, 200 W net output) with a ultrasonic probe in thermostated environment of 80 °C under ambient air. At the same time, ultrasonication activity achieved their decoration on state-of-the-art fuel c...

Two identical four air-cathode single chamber membrane-less microbial fuel cells were stacked and tested under in series and in parallel electrical configurations. Fermentable household waste extract (FORBI; 0.8 g COD/L) was used as substrate, in all cases. Linear Sweep Voltammetry (LSV) was carried out for the construction of polarization curves w...

A four air-cathode single chamber membrane-less microbial fuel cell (MFC) was developed and used to produce energy when fed with fermentable household waste extract (FORBI; 0.8 g COD/L). The employment of MnO2 as the cathode catalyst at a loading of 89 mg /cm2, the use of food residue biomass (FORBI) and the single chamber design provided a maximum...

A stack of two identical single chamber microbial fuel cells (MFCs) was assessed during using fermentable house hold extract as substrate. The design of the MFC units was based on the single chamber membrane-less technology using four cathode electrodes. The total power output was 492 mW either in series or parallel connection considering a total a...

Metal-organic frameworks (MOFs) have received a lot of attention due to their unique properties and abundant functionalities. Permanent porosity and high surface area are just a few traits that have made them attractive to researchers. They can be prepared as task-specific materials by exploiting the functional group variety and tuning their size a...

Perovskite is a versatile group of oxide materials allowing their properties to be tailored by composition towards specific requirements. LaAlO3 was prepared to study and report its properties in the context of its potential in thermal barrier coatings (TBCs) technology. A citric acid method was used for synthesis and the perovskite structure was c...

Microstructure degradation of LSCF cathodes for Solid Oxide Fuel Cells

Titanium dioxide is the most popular photocatalyst to degrade organic pollutants in air, as well as in water. The principal drawback preventing its commercial application lies in its limited absorption of the visible light (400-700 nm), while it is active under UV irradiation (≤ 387 nm). Supporting noble metals in the form of nanoparticles on TiO2...

Apatite-type lanthanum silicates (ATLS) are attracting a great interest as new class of solid electrolytes possessing high oxide-ion conductivity at relatively low temperatures for solid oxide fuel cells (SOFC). In this study, doped ATLS of the composition La9.83Si6-x-yAlxFeyO26±δ (x: 0, 0.25, 0.75, 1.5 and/or y: 0, 0.25, 0.75, 1.5) were successful...

Simultaneous electrocatalytic Pt-nanoparticle synthesis and decoration of Vulcan XC-72 carbon black substrate was achieved in a novel one-step-process, combining galvanostatic pulsed electrodeposition and pulsed ultrasonication with high power, low-frequency (20 kHz) ultrasound. Aqueous chloroplatinic acid precursor baths, as well as carbon black s...

The fluorine-doped solid solution with double perovskite structure Ba4Ca2Nb2O11-0.5xFx was synthesized using the solid state method. It was found that the homogeneity region was limited by the composition Ba4Ca2Nb2O10.6F0.8. Structure and electrical properties of the solid solution have been investigated. Electrical conductivities were measured by...

Copper and nickel nanoparticles were synthesized using reducing agents in the presence of direct high energy ultra-sonication. The metallic nanoparticles were decorated on various ceramic substrates (e.g. α-Al2O3, and TiO2) leading to metal reinforced ceramics with up to 45% metallic content. Different parameters, such as the amount of precursor ma...

The most important drawback of the use of TiO2 as photocatalyst is its lack of activity under visible light. To overcome this problem, the surface modification of commercial micro-sized TiO2 by means of high-energy ultrasound (US), employing CuCl2 as precursor molecule to obtain both metallic copper as well as copper oxides species at the TiO2 surf...

For powders of oxide-ion conductors based on Al/Fe- doped lanthanum silicates as well as Sc+Ce-doped zirconia, the temperature –programmed exchange with C18O2 in the SSITKA mode was applied for estimation of the oxygen self-diffusion coefficients Do. Comparison with results obtained for dense ceramics of these electrolytes using SIMS isotope profil...

Although the TiO2 is one of the most promising materials for its photocatalytic potential related to the pollution abatement, it strongly suffers from the low photocatalytic activity if it is used under visible light and not under UV light. Among the various possible modifications, the surface decoration with metal or metal oxides NPs can be a good...

Metal hydrides are promising compounds for the storage of hydrogen especially in the transport sector. Their high reactivity with moisture and difficult handling in ambient atmosphere prevents their easy application in tanks and thus the market penetration of this very promising and clean technology. In the present work we investigated the way to p...

Low resistance of C/C-SiC composites against oxidation at high temperatures created the need to develop materials that could be used as oxygen protective layers. Yttrium silicate (Y2SiO5) has been proposed as an excellent candidate for this purpose. In order to investigate whether Y2SiO5 is a sufficient barrier against oxygen, the transport paramet...

Decoration of SOFC anode cermets with metal nanoparticles (NPs) enchance their ability and stability in natural gas to hydrogen reform. A novel sonoelectrochemical approach of Au-NPs synthesis (mean 12.31±2.69nm) is suggested, according to which the sonication is held constant while the electrochemical activity is either pulsed or continuous. The g...

The use of NaBH4 as a hydrogen storage material suffers to some extend from its deficient stability against chemicals and degradation at elevated temperatures. This disadvantage can be overcome by the use of polyelectrolytes as protective layers. Furthermore, the coating of NaBH4 with polyelectrolytes significantly enhances the release of hydrogen...

Rare earth oxyapatites have attracted researcher interest as promising electrolytes due to their thermodynamic stability, robustness (as ceramics) and their ability to maintain distorted crystal structure by doping but more important due to their high oxide ion conductivity at intermediate temperatures. Additionally they exhibit satisfactory refrac...

The growth and the electronic properties of Ba ultra-thin films (coverage ≤ 2 ML) on the SrTiO3(1 0 0) surface was studied using synchrotron radiation facilities. The investigation was carried out mainly by soft X-ray photoelectron spectroscopy measurements at low core levels and the valence band region. The results show that the Ba overlayer devel...

The coupling of electrochemical processes and ultrasound has found a larger number of applications during the past years. Especially in the field of materials science and energy technology its potential for the production of nanomaterials, improved metals, alloys and composites is noteworthy. In this paper the focus is on fundamental studies applyi...

Many efforts have been devoted recently to synthesize nickel particles within the nanometer range mainly due to the important applications of nickel in functional and structural devices. Compared to noble metals, synthesis of nickel nanoparticles through chemical reduction methods presents several difficulties due to its tendency to aggregate and r...

Export Date: 26 February 2014, Source: Scopus, References: Singhal, S.C., (2000) Solid State Ionics., 135, pp. 305-313;

For applications in high temperature fast conductometric gas sensors and oxygen membranes, several mixed conductors show promising features. In particular, acceptor-doped strontium titanate (STO) has been widely investigated for an application as a fast conductometric oxygen sensor. By a B-site substitution with 35% iron, the resulting ceramic soli...

The interaction of H2O with 0.013 at.% Fe-doped SrTiO3(100) was investigated in situ with Metastable Induced Electron Spectroscopy (MIES), Ultraviolet Photoelectron Spectroscopy (UPS) and XPS at room temperature. Low Energy Electron Diffraction (LEED) was applied to gather information about the surface termination. To clear up the influence of surf...

The possibility of the incorporation of oxygen and deuteron stemming from the dissociation of water into iron doped strontium titanate single crystals with two different iron concentrations (0.13 and 0.013at.% Fe) has been investigated. Double labeled water (2H218O) was used for Isotope Exchange Depth Profiling. It acts as an incorporation source o...

Apatite type rare earth silicates are being extensively studied as electrolyte material for intermediate temperature solid oxide fuel cells (SOFC). In this paper we presents results on synthesis of Al and/or Fe-doped ATLS, the design of compatible anode materials, thermal expansion properties and co-sintering of half-cells from expansion matched ma...

The work presents the results of studying the mechanism of oxygen transport for a new promising class of oxygen-containing electrolytes based on lanthanum silicate with an apatite structure using impedance spectroscopy and isotopic oxygen heteroexchange. At 1000 K, in the case of samples with an optimum composition including codoped Fe and Al, σ ∼...

Cubic scandia-stabilised zirconia (ScSZ) has a very high oxygen ion conductivity, significantly higher than the more common yttria-stabilised zirconia (YSZ). However, its practical use is hindered by an ordered rhomboedric phase being present at low temperature which is unique for zirconias. The occurrence of this phase can be suppressed by co-dopi...

In this paper we present a synthesis route for an Y2SiO5 sol derived from tetraethoxysilane and yttrium oxo-isopropoxide where the sol particles show a significant particle charge. The dynamic light scattering method was applied to obtain information on the relation between charging and growth of these sol species. The effect of water concentration...

A polymeric yttrium silicate sol was prepared for the electrophoretic deposition of Y2SiO5 on C/C composite materials. The properties of the sol and the process of electrophoretic deposition (EPD) from the sol on glassy carbon substrates were studied using impedance spectroscopy. During constant voltage electrophoretic deposition first a rapid and...

Apatite-type lanthanum silicates (ATLS) doped by Fe were prepared by using mechanical activation, and the effect of the nature of the dopant raw materials on the formation of ATLS was considered. Genesis of the formation of apatite was studied by XRD, IR, HRTEM, and Mössbauer and UV/Vis electron spectroscopy. The possibility of a partial substituti...

The influence of the experimental conditions on the operation of a quartz crystal microbalance in an ultrasonic field was studied in water and different Cu electrolytes. An increase of the ultrasonic intensity and a decreasing distance between the ultrasonic horn tip and the surface of the quartz resonator caused an increase in signal noise and a d...

The electrochemical characteristics of a La0.8Sr0.2Ni0.4Fe0.6O3 cathode electrode interfaced to La9.83Si5Al0.75Fe0.25O26{plus minus}δ apatite-type electrolyte were studied using AC impedance spectroscopy under open circuit conditions, at temperatures 600 to 800 oC and oxygen partial pressures in the range 0.1 to 20 kPa. The cathode and electrolyte...

The application of ultrasound in electrochemistry has become increasingly popular in the past decade, especially in the field of materials science because of its potential in the production of nanomaterials, metals, alloys and composites with different properties and superior quality, hardness, and homogeneity, but also in analytical chemistry and...

Mullite and mullite/Al2O3 precursor sols have been developed for the deposition of oxidation barrier coatings on carbon fibre reinforced composites using a combination of sol–gel synthesis and electrophoresis.The sols were synthesised by controlled hydrolysis and condensation of TEOS (tetraethoxysilane) and Al(OBus)3 (aluminium tri-sec-butylate). T...

Cited By (since 1996):1, Export Date: 26 February 2014, Source: Scopus, References: Nakayama, S., Kageyama, T., Aono, H., Sadaoka, Y., (1995) J. Mater. Chem, 5, p. 1801;

Catalytic properties and coking stability of composite materials based on NiO and doped apatite-type lanthanum silicates were studied for their using as anode materials for internal methane reforming in intermediate temperature solid oxide fuel cells. Samples based on Sr- or Al-doped lanthanum silicate were prepared by modified Pechini methods. The...

Oxygen diffusion coefficients in SrZrO3 polycrystals were determined using the isotopic exchange method with 18O as oxygen tracer. Diffusion treatments were performed at different temperatures between 1173 K and 1473 K. Oxygen diffusion profiles were established by secondary ion mass spectroscopy (SIMS). Classical diffusion equations were used to f...