Contact person: Jiří Henych
Nanostructured metal oxides (such as TiO2, CeO2, MnO, or Fe oxides) possess exceptional ability to adsorb and chemically transform highly toxic compounds (such as the nerve agents Sarin, Soman or diverse pesticides) to harmless products thanks to their large surface area combined with possible high surface reactivity. The class of nanomaterials that can be activated by light, photocatalytic nanomaterials, may further be tailored for accelerated degradation. We employ the undemanding synthesis methods to produce nanosized single and mixed oxides or their composites and study in depth their physico-chemical properties related to the decontamination activity. Further we focus on elucidating of the degradation mechanism of toxic compounds on metal oxides surfaces.
Figure 1. preparation of the TiO2-Nanodiamond composites and its use for the light-induced degradation of organic pollutants
Figure 2. Graphene oxide-based nanocomposites with two different types of TiO2 nanoparticles
Figure 3. Graphene sheet prepared by ultrasonication
To uncover new research areas and applications we combine the metal oxide nanoparticles with new intriguing 2D nanomaterials (such as graphene) or other low-dimensional materials (quantum dots, nanodiamonds) that are prepared by our own developed ultrasonic technology. We are fully equipped for hydrothermal, solution-based, microwave, sonochemical and solid-state syntheses in a lab scale, but we also use the high-volume reactors (15, 50, 100 L) for synthesis up-scaling. Two high-power ultrasonic systems (1kW and 2kW) with steel water-cooled reactors with temperature and pressure control are dedicated to top-down preparation of low-dimensional nanomaterials or sonochemical syntheses.
Figure 4. SEM micrographs of the prepared nanostructured materials
Figure 5. 1kW ultrasonic probe with the stainless steel water-cooled reactor with temperature and pressure control
We study the nanomaterials using the high-end electron microscopes (both SEM and TEM) with elemental mapping, atomic force microscope, or various spectroscopies. For elucidating the reaction mechanism of the (photo)degradation we combine HPLC/DAD, GC-MS methods and in situ DRIFT spectroscopy.
We cooperate on our research topics with Institute of Physics of the CAS (nanodiamond research), J.E. Purkyně University in Ústí nad Labem (degradation of environmental pollutants and new applications of cerium oxide), Military Research Institute in Brno and the National Institute of Nuclear, Chemical and Biological Protection (degradation of chemical warfare agents), Uppsala University (study of photo-induced surface chemical reactions in situ), Bulgarian Academy of Sciences (nanostructured oxides), VŠB- Technical University of Ostrava (photocatalytic materials), etc.
References
J. Henych, M. Šťastný, Z. Němečková, K. Mazanec, J. Tolasz, M. Kormunda, J. Ederer, P. Janoš. Bifunctional TiO2/CeO2 reactive adsorbent/photocatalyst for degradation of bis-p-nitrophenyl phosphate and CWAs. Chem. Eng. J. 2021, 414, 128822.
M. Šťastný, G. Issa, D. Popelková, J. Ederer, M. Kormunda, S. Kříženecká, J. Henych. Nanostructured manganese oxides as highly active catalysts for enhanced hydrolysis of bis(4-nitrophenyl)phosphate and catalytic decomposition of methanol. Catal. Sci. Technol. 2021, 11, 1766-1779.
J. Henych, Š. Stehlík, K. Mazanec, J. Tolasz, J. Čermák, B. Rezek, A. Mattsson, L. Österlund. Reactive adsorption and photodegradation of soman and dimethyl methylphosphonate on TiO2/nanodiamond composites. Appl. Catal. B-Environ. 2019, 259, 118097.
J. Henych, A. Mattsson, J. Tolasz, V. Štengl, L. Österlund. Solar light decomposition of warfare agent simulant DMMP on TiO2/graphene oxide nanocomposites. Catal. Sci. Technol. 2019, 9 (8), 1816-1824.
J. Henych, V. Štengl, A. Mattsson, J. Tolasz, L. Österlund. Chemical warfare agent simulant DMMP reactive adsorption on TiO2/graphene oxide composites prepared via titanium peroxo-complex or urea precipitation. J. Haz. Mat. 2018, 359, 482-490.