We reported on discovery of a new pyrochlore compound, (Bi1.88Fe0.12)(Fe1.42Te0.58)O6.87, which is characterized by the highest Fe content and the most promising photocatalytic properties among all known pyrochlores. Using x-ray and neutron diffraction we determined its crystallographic properties. At 20K the pyrochlore developed strong spin coupling into the spin glass state. At this temperature the influence of the magnetic coupling on dielectric properties was shown, which confirms the magnetoelectric coupling. the band gap was determined to be lower than 2eV, which shows on a great potential of this compound for photocatalytic applications.
COBISS.SI-ID: 1894907
An important contribution to environmental sustainability is represented by development of energy efficient technologies. The current intensive research in electrocaloric (EC) materials has been driven by the quest for new energy efficient and environmentally friendly cooling technologies that would contribute to a reduced carbon footprint. The bottle neck for development of the EC cooling technologies is in the yet still too small EC temperature changes that can be induced in the materials. To overcome this, the research has focused on several segments with an emphasis on development of theoretical understanding, high performance EC materials and smart material engineering. This paper insightfully reviews the progress in these research fields and critically discusses the major advances in order to present a compact picture of the state-of-the-art, extract new knowledge and propose promising future research directions. The invitation to contribute to one of the most prestigious journals in the field of Materials us a great honor for the authors and shows on his scientific reputation in the field
COBISS.SI-ID: 2210043
Combining TiO2 photocatalysis with inorganic oxidants (such as O3 and H2O2) or transition metal ions often leads to a synergy. In this work we studied the disappearance of thiacloprid, a modern neonicotinoid insecticide, applying various advanced oxidation processes and TiO2 photocatalysts. In photocatalytic ozonation experiments, synergic effect of three different TiO2 photocatalysts was quantified. On the contrary, no synergy was observed in photocatalytic degradation of thiacloprid in the presence of dissolved iron(III) species.
COBISS.SI-ID: 1422587
SrTiO3 is considered to be one of the most interesting, but for photocatalytic applications not enough investigated, semiconductive materials. We have paid special attention to the influence of doping on the photocatalytic activity. Within this study we have investigated in details the incorporation mechanisms of dopants; among them Mn. The study resulted in some surprising results on influence of the processing parameters on the atomistic mechanisms of the incorporation and the absence of magnetization in the case of an ideal dopant incorporation. This contradicts and disproves current theories on local fields in this material and, therefore, our work has attracted huge interest and was published in such respected journal as Advanced Functional Materials is.
COBISS.SI-ID: 2265083
Hematites and ferrites are becoming increasingly interesting photocatalysts for immobilized systems for water splitting, where in the form of films are integrated in electrophotocatalytical cells. We have studied immobilization of co-ferrite and structural characteristics of such films. During these studies we discovered auxetic properties. In functional oxide materials the so called molecular auxetic behavior is extremely rare. The CoFe2O4 epitaxial thin film under compressive axial strain reduces its cell dimensions also in the transverse direction with a Poisson’s ratio of -0.85. We identified the hinge-like honeycomb network in the spinel structure that is responsible for the negative Poisson’s ratio. The observed phenomenon importantly affects functional properties of CoFe2O4 and enables a construction of a new class of nanostructures and nano-devices. This discovery has triggered interest of broad scientific community because the influence of the auxetic properties on application of the films is not yet understood. The research is now directed into studies of the influence of external stress on optoelectronic properties and, consequently, the photocatalytic activity. Because of the importance of the discovery we managed to publish this paper in one of the best journals in the field of Material Science, i.e. Advanced Functional Materials.
COBISS.SI-ID: 1382651