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PING Junior 2021 is organized with the support of funds for specific university research project SVK1-2021-008 and ERDF "Research of additive technologies for future applications in the machinery industry - RTI plus" (No. CZ.02.1.01/0.0/0.0/18_069/0010040). Laser ablation in liquids (LAL) has been developed into a simple and versatile technique producing various colloidal nanoparticles with novel properties and applications (e.g. biodetection, bioactive materials and photocatalysis). One of the typical problems faced in the bio/photo catalytic applications nanoparticles is their instability towards aggregation and the formation of larger particles, which change the catalytic properties and can even lead to inactive materials. A strong effort is therefore devoted to achieving a higher colloidal stability by various stabilizers or by suitable liquid media. However, the stabilizers are usually not environmentally friendly and freely moveable nanocatalysts can enter biogeochemical cycles and become harmful to the environment living organisms. It is therefore a novel and attractive idea to make use of the adsorption of nanoparticles on rough surfaces to bind these nanoparticles before they agglomerate in the liquid phase. In this simple way, colloidal photo/bio catalytic nanoparticles could adhere on a porous carrier, functionalize its surface. This unexplored potential of LAL we have revealed for laser ablation of FeS in water and ethanol which produces FeS-derived colloidal nanoparticles that absorb onto immersed porous ceramic substrates and create solar-light photocatalytic surfaces. The laser induced process thus offers an easy and efficient way for the functionalization of porous surfaces by photocatalytic nanoparticles that avoids aggregation in the liquid phase. Moreover, LAL induced functionalization has been found as perspective technique also for enhancing of bioactivity of titanium porous/textured surfaces. The importance of the synergy between the two disciplines: (i) chemical reactions of bone growth stimulants under LAL conditions and (ii) the functionalization of laser-shaped micro/nanotopography of titanium surface with colloidal particles generated from targets of bone growth stimulants by laser ablation in selected liquids is examined. The LAL synthesis of bioconductive colloidal particles of CaTiO3, MgTiO3 and CaSi2 allowing productivity, zeta potential, size and dispersity control through selected irradiation parameters and different liquid medium. The structure and adhesion of the nanosols to titanium surface is assessed by IR, Raman and XP spectroscopy and SEM and TEM analyses. In vitro osseointegration activity of the functionalized surfaces are evaluated by examining the growth of Messenchymal Stem cells.

Smíšené oxidy křemičito-titanové a jejich kompozity byly rozsáhle studovány, zatímco jejich protějškům oxidu titaničitého (TiO) a oxidu křemičitého (SiO) byla věnována velmi malá pozornost. Laserová ablace SiO a TiO v kapalinách je podle literatury zcela neprobádána. Tento článek popisuje Nd: YAG pulzní laserovou ablaci SiO a TiO v ethanolu, která umožňuje tvorbu nanočástic na bázi SiO a TiO a jejich aglomerátů. Smíšený koloid SiO-TiO byl připraven jednoduchým smísením jednotlivých ablativně připravených koloidů v objemovém poměru 1: 1. Měření velikosti částic pomocí dynamického rozptylu světla (DLS) určuje velikosti 24,85 nm a 262,3 nm pro koloid SiO, 494,8 nm pro koloid TiO a 35,2 nm a 397,5 nm pro směsný koloid. Hodnoty Zeta potenciálu naznačují počáteční nestabilitu pro všechny měřené systémy. Morfologie částic zachycených na substrátu Ta odpařením ethanolu byla studována pomocí skenovací elektronové mikroskopie (SEM). Byly pozorovány kulaté, oválné a listové částice a jejich aglomeráty. Ramanova spektroskopie smíšeného koloidu SiO-TiO odhalila vícefázovou strukturu sestávající se z anatasu a rutilu, krystalického a amorfního křemíku a oxidu křemičitého a krystalického a amorfního silicidu titanu TiSi2. Tvorba TiSi2 demonstruje neočekávanou nízkoteplotní disproporci druhů na bázi SiO a TiO a vzájemné redukční interakce. Katalytická aktivita jednotlivých koloidů SiO a TiO a jejich směsí byla testována pomocí degradace methylenové modři (MB) za denního světla. Směs TiO-SiO vykazuje vyšší katalytickou aktivitu vůči slunečnímu světlu ve srovnání s jednotlivými koloidy, což lze vysvětlit přítomností vysoce fotokatalytického TiSi2. Tyto výsledky představují potenciál interakcí redukujících SiO a TiO, které jsou příznivé pro generování fotokatalytických materiálů a sanaci vody. Silica–titania mixed oxides and composites have been extensively studied, whereas to the titanium monoxide (TiO) –silicon monoxide (SiO) counterparts has been devoted very little attention. Laser ablation of SiO and TiO in liquids is in according with literature completely unexplored. Here we report on Nd:YAG pulse laser ablation of SiO and TiO in ethanol which allows generation of SiO- and TiO-based nanoparticles and their agglomerates. Mixed SiO-TiO colloid has been prepared by simple mixing of ablatively prepared individual colloids in 1:1 volume ratio. Measurement of size distribution by Dynamic Light Scattering (DLS) determines sizes of 24.85 nm and 262.3 nm for SiO colloid, 494.8 nm for TiO colloid and 35.2 nm and 397.5 nm for mixed colloid. Zeta potential values suggest incipient instability for all measured systems. Morphology of the particles captured on Ta substrate by evaporation of ethanol was studied using Scanning Electron Microscopy (SEM). Round-shaped, oval, and sheet-like particles and their agglomerates have been observed. Raman spectroscopy of the mixed SiO-TiO colloid revealed multiphase structure consisting of anatase and/or rutile, crystalline and amorphous silicon and silica and crystalline and amorphous titanium silicide TiSi2. Formation of TiSi2 demonstrates unexpected low temperature disproportionation of SiO and TiO-based species and mutual reducing interactions. Catalytic activity of individual SiO and TiO colloids and of their mixture has been tested in terms of methylene blue (MB) degradation under the daylight. TiO-SiO mixture exhibits higher solar-light catalytic activity compared to individual colloids which could by explain by the presence of highly photocatalytic TiSi2. These results represent potential of SiO and TiO reducing interactions which are favorable for generation of photocatalytic materials for water remediation.

Zájem o možnosti přípravy různých oxidů zirkonia z vědeckého i aplikačního hlediska roste. Laserová ablace pevného terče sestávajícího ze slinutých zrn kovového hexagonálního Zr3O a monoklinického ZrO2 vede k odpařování Zr, O částic (iontů, atomů) a následné depozice Zr-O filmu. Jako substráty byly použity Ta a Cu. Filmy byly analyzovány pomocí SEMEDX, Ramanovy a FTIR spektroskopie a rentgenové difrakce. SEM analýza odhalila kontinuálním povlak a kruhovité objekty o velikosti μm / sub-μm. Pomocí Ramanovy spektroskopie byly detekovány široké píky, které mohou naznačovat částečnou laserem indukovanou amorfizaci Zr-O depozitu. FTIR spektroskopie ukazuje pásy, které lze přiřadit vibracím Zr-O nanostrukturovaného oxidu zirkoničitého. Rentgenová difrakční analýza poskytuje jasnější přiřazení deponovaných fází, kde depozice na Ta vykazuje přítomnost monoklinické Zr02, rhombohedrické Zr03 s nedostatkem kyslíku a zajímavě ukazuje přítomnost vysokotlaké ortorombické fáze Zr02. Povlak na Cu sestává z monoklinické Zr02, rhombohedrické Zr30 a metastabilní tetragonální Zr02 fáze. There is a growing interest about the possibilities for preparation of various zirconium oxides from scientific as well asapplication point of view. Laser ablation of solid target consisting of sintered grains of metallic hexagonal Zr3O and monoclinic ZrO2 results in evaporation of Zr, O species (ions, atoms) and subsequent deposition of Zr-O film. Ta and Cu have been used as substrates. The films were analyzed by SEM-EDX, Raman and FTIR spectroscopy and X-ray diffraction. SEM analysis revealed μm/sub-μm sized roundshape and ring-like objects on continuous coat. Using Raman spectroscopy broad peaks which can suggest partial laser induced amorphization of Zr-O deposits were detected. FTIR spectroscopy shows bands which are assignable to Zr-O vibration of nanostructured zirconia. X-ray diffraction analysis provides more explicit assignment of deposited phases where the deposit on Ta exhibits presence of monoclinic ZrO2, oxygen deficient rhombohedric Zr3O and interestingly indicates presence of high-pressure orthorhombic ZrO2 phase. The coat on Cu consists of monoclinic ZrO2, rhombohedric Zr3O, and metastable tetragonal ZrO2 phase.

Směsné oxidy a kompozity oxidu TiO2/SiO2 byly intenzivně studovány, zatímco kekich protějšky oxidu titanatého (TiO) a oxidu křemnatého (SiO) stále zůstávají neprozkoumány. Tato studie odhaluje strukturální změny ve zahřátých směsích SiO-TiO. Změny složení ve smísených mikro-částicích TiO a SiO zahřívaných při 1000 ° C byly zkoumány pomocí FTIR, UV-Vis a Ramanovy spektroskopie, rentgenové difrakce a elektronové mikroskopie (SEM a TEM). Ukazuje se, že dochází k úbytku krystalického TiO a tvorbě suboxidů titanu (Ti2.5O3, Ti2O3), rutilu, elementárního křemíku, silicidu titanu Ti5Si3 a amorfních binárních SiOx, TiOx a ternárních nanostruktur SixTiyOz. Tvorba tohoto Si/Ti/O kompozitu je vysvětlena disproprciací SiO, redukcí TiO křemíkem, přenosem kyslíku (redoxní reakce) mezi TiOx a SiOx a kombinací Ti a Si k získání silicidu titanu. Vytvořený Si/Ti/O kompozit absorbuje viditelné světlo a jeho fotokatalytická aktivita ve slunečním záření byla testována na odbarvování methylenové modři (bBlue) a porovnávána s práškem nezahřátého SiO, TiO a Ti5Si3. Silica–titania mixed oxides and composites have been extensively studied, whereas the titanium monoxide (TiO)–silicon monoxide (SiO) counterparts still remain to be explored. Here, we report on structural changes in heated SiO–TiO mixtures. The changes in composition in intimately mixed μm-sized particles of TiO and SiO heated at 1000 °C were examined by FTIR, UV–Vis and Raman spectroscopy, X-ray diffraction and electron (SEM and TEM) microscopy. They are shown to involve depletion of crystalline TiO and formation of titanium suboxides (Ti2.5O3, Ti2O3), rutile, elemental silicon, titanium silicide Ti5Si3 and amorphous binary SiOx, TiOx and ternary SixTiyOz nano-structures. These constituents of the developed Si/Ti/O composite are explained by SiO disproportionation, reduction of TiO by silicon, oxygen transfer (redox) reactions between TiOx and SiOx species and the combination of Ti and Si to obtain titanium silicide. The produced Si/Ti/O composite absorbs visible light and its solar-light photocatalytic activity in decolorization of methylene bBlue is compared to that of the unheated SiO, TiO and Ti5Si3 powders.

The cleaning of particles from library materials (paper, textile, and collagen materials) using a high-speed CO2 snow jet was investigated. The measurements included\ndetermination of the cleaning efficiency, and evaluation of possible adverse effects. The method was compared with nitrogen jet cleaning. The results showed that the CO2 snow\njet is able to effectively remove particles from the surfaces. Any adverse effects were not observed at paper and textile. However, application on collagen materials caused\ndegradation of the surface.

The catalysts investigated in this work were prepared by co-precipitation of nitrates with aqueous K2CO3/KOH solution, followed by washing the precipitates to varying degrees of potassium content and calcining the precursors at 500 °C for 4 h. Mn-Al potassium salt followed by calcination at 500 °C. Before the catalytic reaction, they were calcined at 700 °C. The catalysts and their precursors were characterized by the following measurement techniques: ICP, DTG, XRD, N2 physisorption, FTIR, H2-TPR, CO2-TPD, XPS, and thermal alkali metal desorption (SR-TAD).\n\n

The nucleation of nanoparticles was applied during gold deposition onto TiO2 layers. For nucleation, up to 10 Pa of inert gas (argon) was used. Argon molecules efficiently helped to cool temperature of evolving plume and initiated the nucleation which resulted in deposition of gold nanoislands. Gold nanoparticles incorporated in TiO2 layers provided plasmonic properties. Au/TiO2 layers were used for water splitting as proved by photoelectrochemical measurements.