This page has only limited features, please log in for full access.
Nanostructured electrochromic V2O5 thin films were prepared using spray pyrolysis technique growth at a temperature of 250 °C using air-carrier spray deposition, starting from ammonium metavanadate precursor in water, followed by annealing at 400 °C in O2 atmosphere for 2 h. The V2O5 films were characterized by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy, and their electrochromic behavior was studied using optical spectroscopy and cyclic voltammetry in both the as-deposited and postannealing case. The studies showed that the simple, cost -effective, suitable for large area deposition method used can lead to an interesting surface structuring with large active surface properties suitable for electrochromic applications. Further studies for growth optimization and improvements of films properties and stability are to be performed.
Kyriakos Mouratis; Ioan Valentin Tudose; Andrianna Bouranta; Cristina Pachiu; Cosmin Romanitan; Oana Tutunaru; Stelios Couris; Emmanouel Koudoumas; Mirela Suchea. Annealing Effect on the Properties of Electrochromic V2O5 Thin Films Grown by Spray Deposition Technique. Nanomaterials 2020, 10, 2397 .
AMA StyleKyriakos Mouratis, Ioan Valentin Tudose, Andrianna Bouranta, Cristina Pachiu, Cosmin Romanitan, Oana Tutunaru, Stelios Couris, Emmanouel Koudoumas, Mirela Suchea. Annealing Effect on the Properties of Electrochromic V2O5 Thin Films Grown by Spray Deposition Technique. Nanomaterials. 2020; 10 (12):2397.
Chicago/Turabian StyleKyriakos Mouratis; Ioan Valentin Tudose; Andrianna Bouranta; Cristina Pachiu; Cosmin Romanitan; Oana Tutunaru; Stelios Couris; Emmanouel Koudoumas; Mirela Suchea. 2020. "Annealing Effect on the Properties of Electrochromic V2O5 Thin Films Grown by Spray Deposition Technique." Nanomaterials 10, no. 12: 2397.
The need for clean and efficient energy storage has become the center of attention due to the eminent global energy crisis and growing ecological concerns. A key component in this effort is the ultra-high performance battery, which will play a major role in the energy industry. To meet the demands in portable electronic devices, electric vehicles, and large-scale energy storage systems, it is necessary to prepare advanced batteries with high safety, fast charge ratios, and discharge capabilities at a low cost. Cathode materials play a significant role in determining the performance of batteries. Among the possible electrode materials is vanadium pentoxide, which will be discussed in this review, due to its low cost and high theoretical capacity. Additionally, aqueous electrolytes, which are environmentally safe, provide an alternative approach compared to organic media for safe, cost-effective, and scalable energy storage. In this review, we will reveal the industrial potential of competitive methods to grow cathodes with excellent stability and enhanced electrochemical performance in aqueous media and lay the foundation for the large-scale production of electrode materials.
Dimitra Vernardou; Charalampos Drosos; Αndreas Kafizas; Martyn E. Pemble; Emmanouel Koudoumas. Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media. Molecules 2020, 25, 5558 .
AMA StyleDimitra Vernardou, Charalampos Drosos, Αndreas Kafizas, Martyn E. Pemble, Emmanouel Koudoumas. Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media. Molecules. 2020; 25 (23):5558.
Chicago/Turabian StyleDimitra Vernardou; Charalampos Drosos; Αndreas Kafizas; Martyn E. Pemble; Emmanouel Koudoumas. 2020. "Towards High Performance Chemical Vapour Deposition V2O5 Cathodes for Batteries Employing Aqueous Media." Molecules 25, no. 23: 5558.
In this paper, the optimal and safe operation of a hybrid power system based on a fuel cell system and renewable energy sources is analyzed. The needed DC power resulting from the power flow balance on the DC bus is ensured by the FC system via the air regulator or the fuel regulator controlled by the power-tracking control reference or both regulators using a switched mode of the above-mentioned reference. The optimal operation of a fuel cell system is ensured by a search for the maximum of multicriteria-based optimization functions focused on fuel economy under perturbation, such as variable renewable energy and dynamic load on the DC bus. Two search controllers based on the global extremum seeking scheme are involved in this search via the remaining fueling regulator and the boost DC–DC converter. Thus, the fuel economy strategies based on the control of the air regulator and the fuel regulator, respectively, on the control of both fueling regulators are analyzed in this study. The fuel savings compared to fuel consumed using the static feed-forward control are 6.63%, 4.36% and 13.72%, respectively, under dynamic load but without renewable power. With renewable power, the needed fuel cell power on the DC bus is lower, so the fuel cell system operates more efficiently. These percentages are increased to 7.28%, 4.94% and 14.97%.
Nicu Bizon; Mircea Raceanu; Emmanouel Koudoumas; Adriana Marinoiu; Emmanuel Karapidakis; Elena Carcadea. Renewable/Fuel Cell Hybrid Power System Operation Using Two Search Controllers of the Optimal Power Needed on the DC Bus. Energies 2020, 13, 6111 .
AMA StyleNicu Bizon, Mircea Raceanu, Emmanouel Koudoumas, Adriana Marinoiu, Emmanuel Karapidakis, Elena Carcadea. Renewable/Fuel Cell Hybrid Power System Operation Using Two Search Controllers of the Optimal Power Needed on the DC Bus. Energies. 2020; 13 (22):6111.
Chicago/Turabian StyleNicu Bizon; Mircea Raceanu; Emmanouel Koudoumas; Adriana Marinoiu; Emmanuel Karapidakis; Elena Carcadea. 2020. "Renewable/Fuel Cell Hybrid Power System Operation Using Two Search Controllers of the Optimal Power Needed on the DC Bus." Energies 13, no. 22: 6111.
The incorporation of graphene nanoplatelets (GnPs) within a polymer matrix can play an important role in the physical properties and the functionality of the composite material. Composites consisting of low-density polyethylene (LDPE) and GnPs of different concentrations were developed by mixing GnPs with a molten form of the polymeric matrix. The effect of the GnPs content on the morphological, structural, and electrical properties of the composites were investigated. As shown, graphene presence and its concentration significantly modified the polymer matrix properties, a behavior that can be employed for tailoring its applicability in electrical applications. It was found that the increase of the graphene platelets concentration seems to promote the formation of graphene agglomerates, air gaps, and inhomogeneities, while higher dielectric constant/lower dielectric losses can be achieved.
Athena Maniadi; Maria Vamvakaki; Mirela Suchea; Ioan Valentin Tudose; Marian Popescu; Cosmin Romanitan; Cristina Pachiu; Octavian N. Ionescu; Zaharias Viskadourakis; George Kenanakis; Emmanouel Koudoumas. Effect of Graphene Nanoplatelets on the Structure, the Morphology, and the Dielectric Behavior of Low-Density Polyethylene Nanocomposites. Materials 2020, 13, 4776 .
AMA StyleAthena Maniadi, Maria Vamvakaki, Mirela Suchea, Ioan Valentin Tudose, Marian Popescu, Cosmin Romanitan, Cristina Pachiu, Octavian N. Ionescu, Zaharias Viskadourakis, George Kenanakis, Emmanouel Koudoumas. Effect of Graphene Nanoplatelets on the Structure, the Morphology, and the Dielectric Behavior of Low-Density Polyethylene Nanocomposites. Materials. 2020; 13 (21):4776.
Chicago/Turabian StyleAthena Maniadi; Maria Vamvakaki; Mirela Suchea; Ioan Valentin Tudose; Marian Popescu; Cosmin Romanitan; Cristina Pachiu; Octavian N. Ionescu; Zaharias Viskadourakis; George Kenanakis; Emmanouel Koudoumas. 2020. "Effect of Graphene Nanoplatelets on the Structure, the Morphology, and the Dielectric Behavior of Low-Density Polyethylene Nanocomposites." Materials 13, no. 21: 4776.
A new approach regarding the development of nanostructured V2O5 electrochromic thin films at low temperature (250 °C), using air-carrier spray deposition and ammonium metavanadate in water as precursor is presented. The obtained V2O5 films were characterized by X-ray diffraction, scanning electron microscopy and Raman spectroscopy, while their electrochromic response was studied using UV-vis absorption spectroscopy and cyclic voltammetry. The study showed that this simple, cost effective, suitable for large area deposition method can lead to V2O5 films with large active surface for electrochromic applications.
Kyriakos Mouratis; Valentin Tudose; Cosmin Romanitan; Cristina Pachiu; Oana Tutunaru; Mirela Suchea; Stelios Couris; Dimitra Vernardou; Koudoumas Emmanouel. Electrochromic Performance of V2O5 Thin Films Grown by Spray Pyrolysis. Materials 2020, 13, 3859 .
AMA StyleKyriakos Mouratis, Valentin Tudose, Cosmin Romanitan, Cristina Pachiu, Oana Tutunaru, Mirela Suchea, Stelios Couris, Dimitra Vernardou, Koudoumas Emmanouel. Electrochromic Performance of V2O5 Thin Films Grown by Spray Pyrolysis. Materials. 2020; 13 (17):3859.
Chicago/Turabian StyleKyriakos Mouratis; Valentin Tudose; Cosmin Romanitan; Cristina Pachiu; Oana Tutunaru; Mirela Suchea; Stelios Couris; Dimitra Vernardou; Koudoumas Emmanouel. 2020. "Electrochromic Performance of V2O5 Thin Films Grown by Spray Pyrolysis." Materials 13, no. 17: 3859.
In order to enhance the mechanical performance of three-dimensional (3D) printed structures fabricated via commercially available fused filament fabrication (FFF) 3D printers, novel nanocomposite filaments were produced herein following a melt mixing process, and further 3D printed and characterized. Titanium Dioxide (TiO2) and Antimony (Sb) doped Tin Oxide (SnO2) nanoparticles (NPs), hereafter denoted as ATO, were selected as fillers for a polymeric acrylonitrile butadiene styrene (ABS) thermoplastic matrix at various weight % (wt%) concentrations. Tensile and flexural test specimens were 3D printed, according to international standards. It was proven that TiO2 filler enhanced the overall tensile strength by 7%, the flexure strength by 12%, and the micro-hardness by 6%, while for the ATO filler, the corresponding values were 9%, 13%, and 6% respectively, compared to unfilled ABS. Atomic force microscopy (AFM) revealed the size of TiO2 (40 ± 10 nm) and ATO (52 ± 11 nm) NPs. Raman spectroscopy was performed for the TiO2 and ATO NPs as well as for the 3D printed nanocomposites to verify the polymer structure and the incorporated TiO2 and ATO nanocrystallites in the polymer matrix. The scope of this work was to fabricate novel nanocomposite filaments using commercially available materials with enhanced overall mechanical properties that industry can benefit from.
Nectarios Vidakis; Markos Petousis; Athena Maniadi; Emmanuel Koudoumas; Marco Liebscher; Lazaros Tzounis. Mechanical Properties of 3D-Printed Acrylonitrile–Butadiene–Styrene TiO2 and ATO Nanocomposites. Polymers 2020, 12, 1589 .
AMA StyleNectarios Vidakis, Markos Petousis, Athena Maniadi, Emmanuel Koudoumas, Marco Liebscher, Lazaros Tzounis. Mechanical Properties of 3D-Printed Acrylonitrile–Butadiene–Styrene TiO2 and ATO Nanocomposites. Polymers. 2020; 12 (7):1589.
Chicago/Turabian StyleNectarios Vidakis; Markos Petousis; Athena Maniadi; Emmanuel Koudoumas; Marco Liebscher; Lazaros Tzounis. 2020. "Mechanical Properties of 3D-Printed Acrylonitrile–Butadiene–Styrene TiO2 and ATO Nanocomposites." Polymers 12, no. 7: 1589.
In order to expand the mechanical and physical capabilities of 3D-printed structures fabricated via commercially available 3D printers, nanocomposite and microcomposite filaments were produced via melt extrusion, 3D-printed and evaluated. The scope of this work is to fabricate physically and mechanically improved nanocomposites or microcomposites for direct commercial or industrial implementation while enriching the existing literature with the methodology applied. Zinc Oxide nanoparticles (ZnO nano) and Zinc Oxide micro-sized particles (ZnO micro) were dispersed, in various concentrations, in Acrylonitrile Butadiene Styrene (ABS) matrices and printable filament of ~1.75mm was extruded. The composite filaments were employed in a commercial 3D printer for tensile and flexion specimens’ production, according to international standards. Results showed a 14% increase in the tensile strength at 5% wt. concentration in both nanocomposite and microcomposite materials, when compared to pure ABS specimens. Furthermore, a 15.3% increase in the flexural strength was found in 0.5% wt. for ABS/ZnO nano, while an increase of 17% was found on 5% wt. ABS/ZnO micro. Comparing the two composites, it was found that the ABS/ZnO microcomposite structures had higher overall mechanical strength over ABS/ZnO nanostructures.
Nectarios Vidakis; Markos Petousis; Athena Maniadi; Emmanuel Koudoumas; George Kenanakis; Cosmin Romanitan; Oana Tutunaru; Mirela Suchea; John Kechagias. The Mechanical and Physical Properties of 3D-Printed Materials Composed of ABS-ZnO Nanocomposites and ABS-ZnO Microcomposites. Micromachines 2020, 11, 615 .
AMA StyleNectarios Vidakis, Markos Petousis, Athena Maniadi, Emmanuel Koudoumas, George Kenanakis, Cosmin Romanitan, Oana Tutunaru, Mirela Suchea, John Kechagias. The Mechanical and Physical Properties of 3D-Printed Materials Composed of ABS-ZnO Nanocomposites and ABS-ZnO Microcomposites. Micromachines. 2020; 11 (6):615.
Chicago/Turabian StyleNectarios Vidakis; Markos Petousis; Athena Maniadi; Emmanuel Koudoumas; George Kenanakis; Cosmin Romanitan; Oana Tutunaru; Mirela Suchea; John Kechagias. 2020. "The Mechanical and Physical Properties of 3D-Printed Materials Composed of ABS-ZnO Nanocomposites and ABS-ZnO Microcomposites." Micromachines 11, no. 6: 615.
Sustainability in additive manufacturing refers mainly to the recycling rate of polymers and composites used in fused filament fabrication (FFF), which nowadays are rapidly increasing in volume and value. Recycling of such materials is mostly a thermomechanical process that modifies their overall mechanical behavior. The present research work focuses on the acrylonitrile-butadiene-styrene (ABS) polymer, which is the second most popular material used in FFF-3D printing. In order to investigate the effect of the recycling courses on the mechanical response of the ABS polymer, an experimental simulation of the recycling process that isolates the thermomechanical treatment from other parameters (i.e., contamination, ageing, etc.) has been performed. To quantify the effect of repeated recycling processes on the mechanic response of the ABS polymer, a wide variety of mechanical tests were conducted on FFF-printed specimens. Regarding this, standard tensile, compression, flexion, impact and micro-hardness tests were performed per recycle repetition. The findings prove that the mechanical response of the recycled ABS polymer is generally improved over the recycling repetitions for a certain number of repetitions. An optimum overall mechanical behavior is found between the third and the fifth repetition, indicating a significant positive impact of the ABS polymer recycling, besides the environmental one.
Nectarios Vidakis; Markos Petousis; Athena Maniadi; Emmanuel Koudoumas; Achilles Vairis; John Kechagias. Sustainable Additive Manufacturing: Mechanical Response of Acrylonitrile-Butadiene-Styrene over Multiple Recycling Processes. Sustainability 2020, 12, 3568 .
AMA StyleNectarios Vidakis, Markos Petousis, Athena Maniadi, Emmanuel Koudoumas, Achilles Vairis, John Kechagias. Sustainable Additive Manufacturing: Mechanical Response of Acrylonitrile-Butadiene-Styrene over Multiple Recycling Processes. Sustainability. 2020; 12 (9):3568.
Chicago/Turabian StyleNectarios Vidakis; Markos Petousis; Athena Maniadi; Emmanuel Koudoumas; Achilles Vairis; John Kechagias. 2020. "Sustainable Additive Manufacturing: Mechanical Response of Acrylonitrile-Butadiene-Styrene over Multiple Recycling Processes." Sustainability 12, no. 9: 3568.
Polythiophene/nickel nanocomposites were synthesized by the electrochemical oxidative polymerization of thiophene in the presence of nickel nanoparticles. The nanocomposites were characterized by scanning electron microscopy, energy dispersive X-ray analysis, atomic force microscopy and Raman spectroscopy. It was found that both PTh and PTh/Ni nanocomposites show granular structures with grains that agglomerate. The increasing of the Ni content results in a decreasing in size and an increasing in density of insular PTh/Ni agglomerations. All composite samples present smaller grains and agglomerations as compared to pure PTh. As the Ni content increases both Ra and RMS are slightly increasing. Surface area was also estimated and the results showed a slightly increase of active surface area. Their electrochemical properties were further evaluated utilizing cyclic voltammetry. As-grown nanocomposites of PTh/nickel with the highest content of nickel exhibited enhanced electrochemical activity, the highest specific capacitance of 3000 F g−1 and the fastest discharging process of 200 s.
Petronela Pascariu; Dimitra Vernardou; Mirela Petruta Suchea; Anton Airinei; Laura Ursu; Ștefan Bucur; Ioan Valentin Tudose; Octavian Narcis Ionescu; Emmanouel Koudoumas. Tuning electrical properties of polythiophene/nickel nanocomposites via fabrication. Materials & Design 2019, 182, 108027 .
AMA StylePetronela Pascariu, Dimitra Vernardou, Mirela Petruta Suchea, Anton Airinei, Laura Ursu, Ștefan Bucur, Ioan Valentin Tudose, Octavian Narcis Ionescu, Emmanouel Koudoumas. Tuning electrical properties of polythiophene/nickel nanocomposites via fabrication. Materials & Design. 2019; 182 ():108027.
Chicago/Turabian StylePetronela Pascariu; Dimitra Vernardou; Mirela Petruta Suchea; Anton Airinei; Laura Ursu; Ștefan Bucur; Ioan Valentin Tudose; Octavian Narcis Ionescu; Emmanouel Koudoumas. 2019. "Tuning electrical properties of polythiophene/nickel nanocomposites via fabrication." Materials & Design 182, no. : 108027.
E. Drakakis; M. Suchea; V. Tudose; G. Kenanakis; D. Stratakis; K. Dangakis; A. Miaoudakis; D. Vernardou; E. Koudoumas. Zinc oxide-graphene based composite layers for electromagnetic interference shielding in the GHz frequency range. Thin Solid Films 2018, 651, 152 -157.
AMA StyleE. Drakakis, M. Suchea, V. Tudose, G. Kenanakis, D. Stratakis, K. Dangakis, A. Miaoudakis, D. Vernardou, E. Koudoumas. Zinc oxide-graphene based composite layers for electromagnetic interference shielding in the GHz frequency range. Thin Solid Films. 2018; 651 ():152-157.
Chicago/Turabian StyleE. Drakakis; M. Suchea; V. Tudose; G. Kenanakis; D. Stratakis; K. Dangakis; A. Miaoudakis; D. Vernardou; E. Koudoumas. 2018. "Zinc oxide-graphene based composite layers for electromagnetic interference shielding in the GHz frequency range." Thin Solid Films 651, no. : 152-157.
Minas M. Stylianakis; Dimitrios Konios; Georgios Viskadouros; Dimitra Vernardou; Nikolaos Katsarakis; Emmanuel Koudoumas; Spiros H. Anastasiadis; Emmanuel Stratakis; Emmanuel Kymakis. Ternary organic solar cells incorporating zinc phthalocyanine with improved performance exceeding 8.5%. Dyes and Pigments 2017, 146, 408 -413.
AMA StyleMinas M. Stylianakis, Dimitrios Konios, Georgios Viskadouros, Dimitra Vernardou, Nikolaos Katsarakis, Emmanuel Koudoumas, Spiros H. Anastasiadis, Emmanuel Stratakis, Emmanuel Kymakis. Ternary organic solar cells incorporating zinc phthalocyanine with improved performance exceeding 8.5%. Dyes and Pigments. 2017; 146 ():408-413.
Chicago/Turabian StyleMinas M. Stylianakis; Dimitrios Konios; Georgios Viskadouros; Dimitra Vernardou; Nikolaos Katsarakis; Emmanuel Koudoumas; Spiros H. Anastasiadis; Emmanuel Stratakis; Emmanuel Kymakis. 2017. "Ternary organic solar cells incorporating zinc phthalocyanine with improved performance exceeding 8.5%." Dyes and Pigments 146, no. : 408-413.
Marianthi Panagopoulou; Dimitra Vernardou; Emmanuel Koudoumas; Dimitris Tsoukalas; Yannis S. Raptis. Oxygen and temperature effects on the electrochemical and electrochromic properties of rf-sputtered V2O5 thin films. Electrochimica Acta 2017, 232, 54 -63.
AMA StyleMarianthi Panagopoulou, Dimitra Vernardou, Emmanuel Koudoumas, Dimitris Tsoukalas, Yannis S. Raptis. Oxygen and temperature effects on the electrochemical and electrochromic properties of rf-sputtered V2O5 thin films. Electrochimica Acta. 2017; 232 ():54-63.
Chicago/Turabian StyleMarianthi Panagopoulou; Dimitra Vernardou; Emmanuel Koudoumas; Dimitris Tsoukalas; Yannis S. Raptis. 2017. "Oxygen and temperature effects on the electrochemical and electrochromic properties of rf-sputtered V2O5 thin films." Electrochimica Acta 232, no. : 54-63.
E. Drakakis; E. Kymakis; G. Tzagkarakis; D. Louloudakis; Michael Katharakis; G. Kenanakis; Mirela Petruta Suchea; V. Tudose; Emmanuel Koudoumas. A study of the electromagnetic shielding mechanisms in the GHz frequency range of graphene based composite layers. Applied Surface Science 2017, 398, 15 -18.
AMA StyleE. Drakakis, E. Kymakis, G. Tzagkarakis, D. Louloudakis, Michael Katharakis, G. Kenanakis, Mirela Petruta Suchea, V. Tudose, Emmanuel Koudoumas. A study of the electromagnetic shielding mechanisms in the GHz frequency range of graphene based composite layers. Applied Surface Science. 2017; 398 ():15-18.
Chicago/Turabian StyleE. Drakakis; E. Kymakis; G. Tzagkarakis; D. Louloudakis; Michael Katharakis; G. Kenanakis; Mirela Petruta Suchea; V. Tudose; Emmanuel Koudoumas. 2017. "A study of the electromagnetic shielding mechanisms in the GHz frequency range of graphene based composite layers." Applied Surface Science 398, no. : 15-18.
Vanadium pentoxide (V2O5) is doped for the first time with Mg, and the influence of Mg content on the films properties and functionality is investigated in detail, emphasis given on the electrochemical and electrochromic response. The Mg-doped V2O5 films exhibit characteristics suitable for lithium ion batteries and electrochromic window applications, the optimization of the functionality depending on the Mg content. Low Mg content (2 at. % Mg) appears to favor lithium ion battery applications, the corresponding films exhibiting high specific discharge capacity, increased diffusion coefficient, and high capacity retention. In contrast, high Mg content (15 at. % Mg) is more favorable for electrochromic windows, presenting fast switching response time, high coloration efficiency, and high visible transmittance. In both cases, the determined characteristics are superior or at least equivalent to those reported for V2O5 doped with other transition metals. The obtained results clearly indicate that tuning of the Mg doping enables the growth of thin films with application-centered characteristics.
Marianthi Panagopoulou; Dimitra Vernardou; Emmanuel Koudoumas; Nikos Katsarakis; Dimitris Tsoukalas; Yannis S. Raptis. Tunable Properties of Mg-Doped V2O5 Thin Films for Energy Applications: Li-Ion Batteries and Electrochromics. The Journal of Physical Chemistry C 2016, 121, 70 -79.
AMA StyleMarianthi Panagopoulou, Dimitra Vernardou, Emmanuel Koudoumas, Nikos Katsarakis, Dimitris Tsoukalas, Yannis S. Raptis. Tunable Properties of Mg-Doped V2O5 Thin Films for Energy Applications: Li-Ion Batteries and Electrochromics. The Journal of Physical Chemistry C. 2016; 121 (1):70-79.
Chicago/Turabian StyleMarianthi Panagopoulou; Dimitra Vernardou; Emmanuel Koudoumas; Nikos Katsarakis; Dimitris Tsoukalas; Yannis S. Raptis. 2016. "Tunable Properties of Mg-Doped V2O5 Thin Films for Energy Applications: Li-Ion Batteries and Electrochromics." The Journal of Physical Chemistry C 121, no. 1: 70-79.
Hydrothermal growth of manganese dioxide (MnO2) nanostructures was carried out on indium tin dioxide glass substrates at 95°C for 24 h to study the effect of cations such as K+, Li+, and Na+ on their properties. It was observed that presence of cations affected the MnO2 phase and morphology: amorphous MnO2 (no cations) showed columnar-like structure, ε-MnO2 (K+) presented nanowires, α-MnO2 (Na+) was composed of agglomerates of spherical nanoparticles, while β-MnO2 (Li+) consisted of spherical aggregates of nanoparticles. The different electrochemical performance depending on the structure is expected to be useful for application in Li-ion batteries. As-grown ε-MnO2 exhibited lower charge resistance and higher ionic diffusion rate, providing the electrode with enhanced specific discharge capacity of 910 mAh g−1 and capacity retention of 98% after 500 scans. Hence, K+ can support tunnel structures and stabilize the structure compared with the smaller cations Na+ and Li+.
Dimitra Vernardou; A. Kazas; M. Apostolopoulou; N. Katsarakis; Emmanuel Koudoumas. Cationic Effect on the Electrochemical Characteristics of the Hydrothermally Grown Manganese Dioxide. Journal of Electronic Materials 2016, 46, 2232 -2240.
AMA StyleDimitra Vernardou, A. Kazas, M. Apostolopoulou, N. Katsarakis, Emmanuel Koudoumas. Cationic Effect on the Electrochemical Characteristics of the Hydrothermally Grown Manganese Dioxide. Journal of Electronic Materials. 2016; 46 (4):2232-2240.
Chicago/Turabian StyleDimitra Vernardou; A. Kazas; M. Apostolopoulou; N. Katsarakis; Emmanuel Koudoumas. 2016. "Cationic Effect on the Electrochemical Characteristics of the Hydrothermally Grown Manganese Dioxide." Journal of Electronic Materials 46, no. 4: 2232-2240.
The growth of hematite (FeIII oxide) by atmospheric pressure chemical vapor deposition was possible at 300 oC by controlling the nitrogen flow rate through the iron precursor bubbler. An increase of crystallinity along with the presence of compact interconnected nanoparticles was observed upon increasing the nitrogen flow rate. The amount of incorporated charge was the highest for the 0.6 L min−1 coating presenting reversibility after a period of 1400 s as obtained from chronoamperometry measurements. Additionally, the charge transfer of lithium‐ions across the FeIII oxide / electrolyte interface was easier enhancing its performance presenting capacitance retention of 94 % after 500 scans. The importance of nitrogen flow rate towards the deposition of an anode with good stability and effective electrochemical behavior is highlighted.
Dimitra Vernardou; Maria Apostolopoulou; Nikolaos Katsarakis; Emmanuel Koudoumas; Charalampos Drosos; Ivan P. Parkin. Electrochemical Properties of APCVD α-Fe2 O3 Nanoparticles at 300 o C. ChemistrySelect 2016, 1, 2228 -2234.
AMA StyleDimitra Vernardou, Maria Apostolopoulou, Nikolaos Katsarakis, Emmanuel Koudoumas, Charalampos Drosos, Ivan P. Parkin. Electrochemical Properties of APCVD α-Fe2 O3 Nanoparticles at 300 o C. ChemistrySelect. 2016; 1 (10):2228-2234.
Chicago/Turabian StyleDimitra Vernardou; Maria Apostolopoulou; Nikolaos Katsarakis; Emmanuel Koudoumas; Charalampos Drosos; Ivan P. Parkin. 2016. "Electrochemical Properties of APCVD α-Fe2 O3 Nanoparticles at 300 o C." ChemistrySelect 1, no. 10: 2228-2234.
Vanadium dioxides of different crystalline orientation planes have successfully been fabricated by chemical vapor deposition at atmospheric pressure using propanol, ethanol and O2 gas as oxygen sources. The thick a-axis textured monoclinic vanadium dioxide obtained through propanol presented the best electrochemical response in terms of the highest specific discharge capacity of 459 mAh g-1 with a capacitance retention of 97 % after 1000 scans under constant specific current of 2 A g-1. Finally, the electrochemical impedance spectroscopy indicated that the charge transfer of Li+ through the vanadium dioxide / electrolyte interface was easier for this sample enhancing significantly its capacitance performance.
Dimitra Vernardou; Antonia Bei; Dimitris Louloudakis; Nikolaos Katsarakis; Emmanouil Koudoumas. Oxygen source-Oriented Control of APCVD VO2 for Capacitive Applications. Journal of Electrochemical Science and Engineering 2016, 6, 165 -173.
AMA StyleDimitra Vernardou, Antonia Bei, Dimitris Louloudakis, Nikolaos Katsarakis, Emmanouil Koudoumas. Oxygen source-Oriented Control of APCVD VO2 for Capacitive Applications. Journal of Electrochemical Science and Engineering. 2016; 6 (2):165-173.
Chicago/Turabian StyleDimitra Vernardou; Antonia Bei; Dimitris Louloudakis; Nikolaos Katsarakis; Emmanouil Koudoumas. 2016. "Oxygen source-Oriented Control of APCVD VO2 for Capacitive Applications." Journal of Electrochemical Science and Engineering 6, no. 2: 165-173.
D. Vernardou; A. Kazas; M. Apostolopoulou; N. Katsarakis; Emmanuel Koudoumas. Hydrothermal Growth of MnO2 at 95 oC as an Anode Material. International Journal of Thin Films Science and Technology 2016, 5, 121 -127.
AMA StyleD. Vernardou, A. Kazas, M. Apostolopoulou, N. Katsarakis, Emmanuel Koudoumas. Hydrothermal Growth of MnO2 at 95 oC as an Anode Material. International Journal of Thin Films Science and Technology. 2016; 5 (2):121-127.
Chicago/Turabian StyleD. Vernardou; A. Kazas; M. Apostolopoulou; N. Katsarakis; Emmanuel Koudoumas. 2016. "Hydrothermal Growth of MnO2 at 95 oC as an Anode Material." International Journal of Thin Films Science and Technology 5, no. 2: 121-127.
The growth of silver doped vanadium pentoxide was performed by aerosol assisted chemical vapour deposition and found to be optimal at 450° C. Additionally, an increase in crystallinity and a change in preferred orientation of V2O5 was observed upon increasing the silver content. Silver incorporation also resulted in morphological changes in the thin films from rod to pellet-like structures. For higher silver content films the amount of incorporated charge increased and reversibility and repeatability was demonstrated for 500 cycles. Electrochemical impedance spectroscopy determined that the transfer and diffusion of Li+ ions through the cathode-electrolyte interface was assisted by silver loading, hence, enhancing the capacitive performance.
D. Vernardou; I. Marathianou; N. Katsarakis; Emmanuel Koudoumas; I.I. Kazadojev; Shane O'Brien; Martyn Pemble; I.M. Povey. Capacitive behavior of Ag doped V2O5 grown by aerosol assisted chemical vapour deposition. Electrochimica Acta 2016, 196, 294 -299.
AMA StyleD. Vernardou, I. Marathianou, N. Katsarakis, Emmanuel Koudoumas, I.I. Kazadojev, Shane O'Brien, Martyn Pemble, I.M. Povey. Capacitive behavior of Ag doped V2O5 grown by aerosol assisted chemical vapour deposition. Electrochimica Acta. 2016; 196 ():294-299.
Chicago/Turabian StyleD. Vernardou; I. Marathianou; N. Katsarakis; Emmanuel Koudoumas; I.I. Kazadojev; Shane O'Brien; Martyn Pemble; I.M. Povey. 2016. "Capacitive behavior of Ag doped V2O5 grown by aerosol assisted chemical vapour deposition." Electrochimica Acta 196, no. : 294-299.
Ultrafast pump–probe spectroscopy on as-grown graphene oxide single sheet thin layers was employed in order to study their response following ultrafast excitation of electrons in the sp3 hybridized domains. The study of the transient spectra showed the existence of two wavelength regions with distinct responses: a saturable absorption region and a reverse saturable absorption region. The study of the competing responses on these two regions revealed for the first time that these wavelength regions are not stable following excitation but instead they present a dynamic redshift resulting in a crossover wavelength. This marks the transition from saturable to reverse saturable absorption and is dynamic in nature. The ultrafast dynamics of this reported effect may be of crucial importance to the application of graphene-oxide based elements in optoelectronics.
N. Liaros; S. Couris; E. Koudoumas; P. A. Loukakos. Ultrafast Processes in Graphene Oxide during Femtosecond Laser Excitation. The Journal of Physical Chemistry C 2016, 120, 4104 -4111.
AMA StyleN. Liaros, S. Couris, E. Koudoumas, P. A. Loukakos. Ultrafast Processes in Graphene Oxide during Femtosecond Laser Excitation. The Journal of Physical Chemistry C. 2016; 120 (7):4104-4111.
Chicago/Turabian StyleN. Liaros; S. Couris; E. Koudoumas; P. A. Loukakos. 2016. "Ultrafast Processes in Graphene Oxide during Femtosecond Laser Excitation." The Journal of Physical Chemistry C 120, no. 7: 4104-4111.