Miroslava Edelmannov
@vsb.cz
Institute of Environmental Technology
VSB-Technical University of Ostrava
Scopus Publications
Scopus Publications
Tatiparthi Vikram Sagar, Praveen Kumar, Miroslava Filip Edelmannová, Rudolf Ricka, Martin Reli, Kamila Kočí, Peter Nadrah, Saim Emin, Andrijana Sever Škapin, and Urška Lavrenčič Štangar
Elsevier BV
Rudolf Ricka, Agnieszka Wanag, Ewelina Kusiak-Nejman, Dariusz Moszyński, Miroslava Filip Edelmannová, Martin Reli, Zdeněk Baďura, Giorgio Zoppellaro, Radek Zbořil, Antoni W. Morawski,et al.
Elsevier BV
Petr Praus, Aneta Smýkalová, Radim Škuta, Martin Koštejn, Jiří Pavlovský, Jonáš Tokarský, Kryštof Foniok, Miroslava Filip Edelmannová, and Kamila Kočí
Elsevier BV
Viktoriia Berezenko, Muhammad Bilal Hanif, Marcel Sihor, Yilan Zeng, Miroslava Filip Edelmannová, Martin Reli, Hussain Iftikhar, Muhammad Zubair Khan, Tomas Plecenik, Maros Gregor,et al.
Elsevier BV
Martin Reli, Peter Nadrah, Miroslava Filip Edelmannová, Rudolf Ricka, Andrijana Sever Škapin, Urška Lavrenčič Štangar, and Kamila Kočí
Elsevier BV
Chakib Alaoui, Mohamed Karmaoui, Ahmed Bekka, Miroslava Filip Edelmannova, Juan Jesús Gallardo, Javier Navas, Wassila Touati, Imene Kadi Allah, Bruno Figueiredo, João António Labrincha,et al.
Elsevier BV
Viktoriia Liapun, Muhammad Bilal Hanif, Marcel Sihor, Xenia Vislocka, Saravanan Pandiaraj, Unnikrishnan V K, Guru Karthikeyan Thirunavukkarasu, Miroslava Filip Edelmannová, Martin Reli, Olivier Monfort,et al.
Elsevier BV
Marta Valášková, Veronika Blahůšková, Miroslava Filip Edelmannová, Lenka Matějová, Karel Soukup, and Eva Plevová
MDPI AG
This study focused on mullite-based and forsterite-based ceramic bricks fired at 1000 °C from mixtures of fly ash (40 mass%) and kaolins or vermiculites (60 mass%). The structural, physical, and mechanical properties were characterized by X-ray powder diffraction, nitrogen physisorption, mercury porosimetry, thermogravimetry, and compressive strength. In the development of green-material-derived photocatalysts, we evaluated fly ash ceramic bricks based on kaolins and vermiculites, which deserve deeper research. Alkali potassium in the mixtures positively influenced the reduction of the firing temperature, shrinkage, small porosity, and high compressive strength of ceramic bricks. The crystallization of mullite in fly ash was observed on exotherm maxima from 813 to 1025 °C. Muscovite/illite admixture in kaolins precursor of mullite-based ceramics reduced the crystallization temperature of mullite by up to 70 °C. Vermiculite–hydrobiotite–phlogopite in mixed layers of a raw vermiculite precursor of forsterite-based ceramics controlled the formation of enstatite and forsterite in the temperature range from 736 ± 6 °C to 827 ± 6 °C. Mullite- and forsterite-based ceramic bricks were also investigated for photocatalytic hydrogen production. The photocatalytic generation of hydrogen in the presence of mullite-based ceramic bricks was positively correlated with the percentages of Fe2O3 in the lattice of mullites and in the presence of forsterite-based ceramics with the presence of diopside. Mullite-based ceramic produced the highest yield of hydrogen (320 µmol/gcat after 4 h of irradiation) in the presence of mullite with the highest 10.4% substitution of Fe2O3 in the lattice. The forsterite-based ceramic produced the highest hydrogen yields (354 µmol/gcat after 4 h of irradiation) over more active diopside than forsterite.
Miroslava Filip Edelmannová, Martin Reli, Peter Nadrah, Nejc Rozman, Rudolf Ricka, Andrijana Sever Škapin, Miha Nosan, Urška Lavrenčič Štangar, and Kamila Kočí
Elsevier BV
Petr Praus, Lenka Řeháčková, Jakub Čížek, Aneta Smýkalová, Martin Koštejn, Jiří Pavlovský, Miroslava Filip Edelmannová, and Kamila Kočí
Springer Science and Business Media LLC
AbstractGraphitic carbon nitride (C3N4) was synthesised from melamine at 550 °C for 4 h in the argon atmosphere and then was reheated for 1–3 h at 500 °C in argon. Two band gaps of 2.04 eV and 2.47 eV were observed in all the synthetized materials. Based on the results of elemental and photoluminescence analyses, the lower band gap was found to be caused by the formation of vacancies. Specific surface areas of the synthetized materials were 15–18 m2g−1 indicating that no thermal exfoliation occurred. The photocatalytic activity of these materials was tested for hydrogen generation. The best photocatalyst showed 3 times higher performance (1547 μmol/g) than bulk C3N4 synthetized in the air (547 μmol/g). This higher activity was explained by the presence of carbon (VC) and nitrogen (VN) vacancies grouped in their big complexes 2VC + 2VN (observed by positron annihilation spectroscopy). The effect of an inert gas on the synthesis of C3N4 was demonstrated using Graham´s law of ammonia diffusion. This study showed that the synthesis of C3N4 from nitrogen-rich precursors in the argon atmosphere led to the formation of vacancy complexes beneficial for hydrogen generation, which was not referred so far.
Wassila Touati, Mohamed Karmaoui, Ahmed Bekka, Miroslava Filip Edelmannová, Clarisse Furgeaud, Alaoui Chakib, Imene kadi Allah, Bruno Figueiredo, J. A. Labrincha, Raul Arenal,et al.
Royal Society of Chemistry (RSC)
Synthesis and application of g-C3N4 and graphene/g-C3N4 in H2 production from water splitting, using different g-C3N4 precursors.
Marcel Sihor, Muhammad Bilal Hanif, Guru Karthikeyan Thirunavukkarasu, Viktoriia Liapun, Miroslava Filip Edelmannova, Tomáš Roch, Leonid Satrapinskyy, Tomas Pleceník, Sajid Rauf, Karol Hensel,et al.
Royal Society of Chemistry (RSC)
Facile, single-step, and scalable fabrication of large-area (∼20 cm2) TiO2 nanostructures (TNS) with promising photocatalytic activity and hydrogen production rate under UVA light was carried out via electrochemical anodization.
Beatriz Trindade Barrocas, Jan Přech, Miroslava Filip Edelmannová, Ewelina Szaniawska, Kamila Kočí, and Jiří Čejka
Elsevier BV
Emilia Alwin, Robert Wojcieszak, Kamila Kočí, Miroslava Edelmannová, Michał Zieliński, Agata Suchora, Tomasz Pędziński, and Mariusz Pietrowski
MDPI AG
Pt, Ru, and Ir were introduced onto the surface of graphitic carbon nitride (g-C3N4) using the wet impregnation method. A reduction of these photocatalysts with hydrogen causes several changes, such as a significant increase in the specific surface area, a C/N atomic ratio, a number of defects in the crystalline structure of g-C3N4, and the contribution of nitrogen bound to the amino and imino groups. According to the X-ray photoelectron spectroscopy results, a transition layer is formed at the g-C3N4/metal nanoparticle interphase, which contains metal at a positive degree of oxidation bonded to nitrogen. These structural changes significantly enhanced the photocatalytic activity in the production of hydrogen through the water-splitting reaction. The activity of the platinum photocatalyst was 24 times greater than that of pristine g-C3N4. Moreover, the enhanced activity was attributed to significantly better separation of photogenerated electron–hole pairs on metal nanoparticles and structural distortions of g-C3N4.
Huiqin Wang, Haopeng Jiang, Pengwei Huo, Miroslava Filip Edelmannová, Libor Čapek, and Kamila Kočí
Elsevier BV
Miroslava Edelmannová, Martin Reli, Kamila Kočí, Ilias Papailias, Nadia Todorova, Tatiana Giannakopoulou, Panagiotis Dallas, Eamonn Devlin, Nikolaos Ioannidis, and Christos Trapalis
MDPI AG
Pure g-C3N4 sample was prepared by thermal treatment of melamine at 520 °C, and iron-modified samples (0.1, 0.3 and 1.1 wt.%) were prepared by mixing g-C3N4 with iron nitrate and calcination at 520 °C. The photocatalytic activity of the prepared materials was investigated based on the photocatalytic reduction of CO2, which was conducted in a homemade batch reactor that had been irradiated from the top using a 365 nm Hg lamp. The photocatalyst with the lowest amount of iron ions exhibited an extraordinary methane and hydrogen evolution in comparison with the pure g-C3N4 and g-C3N4 with higher iron amounts. A higher amount of iron ions was not a beneficial for CO2 photoreduction because the iron ions consumed too many photogenerated electrons and generated hydroxyl radicals, which oxidized organic products from the CO2 reduction. It is clear that there are numerous reactions that occur simultaneously during the photocatalytic process, with several of them competing with CO2 reduction.
Miroslava Edelmannová, María de los Milagros Ballari, Michal Přibyl, and Kamila Kočí
Elsevier BV
Martin Reli, Nela Ambrožová, Marta Valášková, Miroslava Edelmannová, Libor Čapek, Christian Schimpf, Mykhaylo Motylenko, David Rafaja, and Kamila Kočí
Elsevier BV
D.M. Tobaldi, K. Kočí, M. Edelmannová, L. Lajaunie, B. Figueiredo, J.J. Calvino, M.P. Seabra, and J.A. Labrincha
Elsevier BV
Abstract Hydrogen, as energy carrier, is a zero-emission fuel. Being green and clean, it is considered to play an important role in energy and environmental issues. Photocatalytic water splitting is a process used to generate hydrogen from the dissociation of water. Titanium dioxide is the archetype material for photocatalytic water splitting. However, because of the fast recombination of the photo-generated exciton, the yield of the reaction is typically low. To overcome this limit, in this work, TiO2 nanoparticles’ surface was modified with copper and graphene to give hybrid nanostructures. Synthesised materials were tested in the photocatalytic hydrogen generation using methanol as the sacrificial agent. X-ray diffraction and spectroscopic results showed that copper did not enter TiO2 structure, and that neither copper nor graphene substantially altered the optical band-gap of prepared photocatalysts. Detailed aberration-corrected high-resolution electron transmission electron imaging and spatially-resolved energy-loss spectroscopy experiments showed the oxidation and amorphisation of graphene nanoplatelets, probably due to the combined action of the acidic media of the solution with the thermal treatment necessary to produce the hybrid materials. Hydrogen generation from methanol/water mix proved that exists an optimum concentration of both copper and graphene (i.e. 0.5 mol% copper plus 0.5 wt% graphene) to grant a two-fold increase in hydrogen production compared to that of unmodified titania when using UVA irradiation. A higher amount of initial graphene was (i.e. 1.0 wt% graphene and 0.5 mol% copper) was instead necessary for granting higher H2 generation upon visible-light exposure. Hybrid materials based on titania modified with both copper oxide and carbon-based materials could therefore be exploited as ideal candidates for light-to-energy applications.
Nadia Todorova, Ilias Papailias, Tatiana Giannakopoulou, Nikolaos Ioannidis, Nikos Boukos, Panagiotis Dallas, Miroslava Edelmannová, Martin Reli, Kamila Kočí, and Christos Trapalis
MDPI AG
g-C3N4, with specific surface area up to 513 m2/g, was prepared via three successive thermal treatments at 550 °C in air with gradual precursor mass decrease. The obtained bulk and exfoliated (1ex, 2ex and 3ex) g-C3N4 were characterized and tested as photocatalysts for H2 production, CO2 reduction and NOx oxidation. The exfoliated samples demonstrated graphene-like morphology with detached (2ex) and sponge-like framework (3ex) of layers. The surface area increased drastically from 20 m2/g (bulk) to 513 m2/g (3ex). The band gap (Eg) increased gradually from 2.70 to 3.04 eV. Superoxide radicals (·O2−) were mainly formed under UV and visible light. In comparison to the bulk, the exfoliated g-C3N4 demonstrated significant increase in H2 evolution (~6 times), CO2 reduction (~3 times) and NOx oxidation (~4 times) under UV light. Despite the Eg widening, the photocatalytic performance of the exfoliated g-C3N4 under visible light was improved too. The results were related to the large surface area and low e−-h+ recombination. The highly exfoliated g-C3N4 demonstrated selectivity towards H2 evolution reactions.
Emilia Alwin, Kamila Kočí, Robert Wojcieszak, Michał Zieliński, Miroslava Edelmannová, and Mariusz Pietrowski
MDPI AG
Graphitic carbon nitride (g-C3N4) was obtained by thermal polymerization of dicyandiamide, thiourea or melamine at high temperatures (550 and 600 °C), using different heating rates (2 or 10 °C min−1) and synthesis times (0 or 4 h). The effects of the synthesis conditions and type of the precursor on the efficiency of g-C3N4 were studied. The most efficient was the synthesis from dicyandiamide, 53%, while the efficiency in the process of synthesis from melamine and thiourea were much smaller, 26% and 11%, respectively. On the basis of the results provided by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–vis), thermogravimetric analysis (TGA), elemental analysis (EA), the best precursor and the optimum conditions of synthesis of g-C3N4 were identified to get the product of the most stable structure, the highest degree of ordering and condensation of structure and finally the highest photocatalytic activity. It was found that as the proton concentration decreased and the degree of condensation increased, the hydrogen yields during the photocatalytic decomposition of water–methanol solution were significantly enhanced. The generation of hydrogen was 1200 µmol g−1 and the selectivity towards hydrogen of more than 98%.
Miroslava Edelmannová, Martin Reli, Lenka Matějová, Ivana Troppová, Lada Dubnová, Libor Čapek, Dana Dvoranová, Piotr Kuśtrowski, and Kamila Kočí
MDPI AG
We describe the successful possibility of the immobilization of a photocatalyst on foam, which is beneficial from a practical point of view. An immobilized photocatalyst is possible for use in a continuous experiment and can be easily separated from the reactor after the reaction concludes. Parent TiO2, La/TiO2, and Nd/TiO2 photocatalysts (containing 0.1 wt.% of lanthanide) were prepared by the sol-gel method and immobilized on Al2O3/SiO2 foam (VUKOPOR A) by the dip-coating method. The photocatalysts were investigated for the photocatalytic hydrogen generation from an aqueous ammonia solution under UVA light (365 nm). The evolution of hydrogen was compared with photolysis, which was limited to zero. The higher hydrogen generation was observed in the presence of 0.1 wt.% La/TiO2 than in 0.1 wt.% Nd/TiO2. This is, besides other things, related to the higher level of the conduction band, which was observed for 0.1 wt.% La/TiO2. The higher conduction band’s position is more effective for hydrogen production from ammonia decomposition.
Xin Li, Miroslava Edelmannová, Pengwei Huo, and Kamila Kočí
Springer Science and Business Media LLC
CdS/g-C3N4 (CdS/CN) type II heterojunction photocatalyst was prepared by an improved successive ionic layer adsorption and reaction process. TEM results show that the CdS nanoparticles (CdS NPs) were successfully loaded on the surface of CN. The results of PL and PEC display that the construction of CdS/CN heterojunction benefits the transmission of the photogenerated carriers and effectively inhibits the photogenerated carrier recombination in photocatalytic process. The photodegradation experiments exhibit that the 3-CdS/CN photocatalyst possesses the highest photodegradation performance over the other samples. The yields of H2 and CH4, in the presence of the best CdS/CN photocatalyst (1-CdS/CN) are 50 and 13 times stronger, respectively, than in the case of the pure CN in the photoreduction process of CO2. The CN coupling effectively improves the photocatalytic performance of CdS-based photocatalyst and inhibits the hole-induced photocorrosion of CdS NPs. A possible type II heterojunction photocatalytic mechanism has been provided.
Kamila Kočí, Han Dang Van, Miroslava Edelmannová, Martin Reli, and Jeffrey C.S. Wu
Elsevier BV
Abstract C3N4 is an abundant carbon based, conjugated polymer with an attractive electronic band structure and increased physicochemical stability. As far as photocatalytic CO2 reduction is concerned, the adsorption of CO2 on the surface of C3N4 based photocatalyst is the first step of the reaction mechanism. In case of the combination of C3N4 with metal complexes such as those of Pt, C3N4 acts as a visible light harvesting system and catalyst whereas Pt complex provides the CO2 active sites. The complex method of the photocatalytic reduction of CO2 emissions in the presence of photocatalyst can be done using previously published methods The pristine C3N4 (g- C3N4 and p- C3N4) and platinum doped C3N4 photocatalysts with 3 wt% of Pt were prepared by two different ways and investigated for the photocatalytic reduction of CO2. The main detected reaction products were methane, hydrogen and carbon monoxide. The physico-chemical properties of photocatalysts were characterized in detail by low-temperature nitrogen physisorption, X-ray powder diffraction and diffuse reflectance UV–Vis spectroscopy. The highest yields of CH4, H2 and CO were achieved in presence of 3 wt% Pt/p-C3N4. The correlation between textural, optical and photoelectrochemical properties and the photocatalysts activity was a subject of this research.