Search results for: SURFACE PROPERTIES
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Rare earth ions doped K 2 Ta 2 O 6 photocatalysts with enhanced UV–vis light activity
PublicationNew rare earth-doped K2Ta2O6 photocatalysts were successfully synthesized by hydrothermal method. The effect of dopant type (Y,Yb,Ho,Pr,Er) and amount of rare earth precursor (2,4,8 and 10 mol%) on the physicochemical and photocatalytic properties of RE-K2Ta2O6 have been investigated. All as-prepared materials were characterized by UV–vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller specific surface area measurement,...
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Using water sources extent during inundation as a reliable predictor for vegetation zonation in a natural wetland floodplain
PublicationDistinctive zones of inundation water during floods were shown to originate from different sources in some major floodplains around the world. Recent research showed that the zonation of water in rivers and floodplains is related to vegetation patterns. In spite of this, water source zones were not used for vegetation modeling due to difficulties in their delineation. In this study, we used simulation results of a fully-coupled...
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Nickel phase deposition on V2CTx/V2AlC as catalyst precursors for a dry methane reforming: The effect of the deposition method on the morphology and catalytic activity
PublicationDry reforming of methane (DRM) is a promising alternative technology for the production of syngas with simultaneous utilization of two main greenhouse gases (CH4, CO2). However, DRM technology is still an industrially immature process due to the lack of stable and active catalyst. Therefore, the search for new catalytic materials is of great research interest. Recently, MAX and MXenes materials are increasingly being tested as...
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On the differential effect of temperature on the Nusselt-Rayleigh relationship in free convection
PublicationThe aim of and inspiration behind this paper was to explain the reasons, also observed by other researchers, of the discrepancy in the results of experimental free convection, which for small Rayleigh and Nusselt numbers in the initial phase of research can sometimes reach several hundred percent. These discrepancies decrease with increasing heating power and plate surface temperature, in proportion to the increase in Ra and Nu,...
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Ionic liquid as morphology-directing agent of two-dimensional Bi2WO6: New insight into photocatalytic and antibacterial activity
PublicationAn efficient and durable utilization of light to drive photocatalytic reactions still requires the overcoming of barriers. Herein, two-dimensional (2D) ultrathin IL_Bi2WO6 (IL_BWO) photocatalysts were prepared for the first time via ionic liquid-assisted hydrothermal route by adjusting the amount of tetrabutylammonium chloride [TBA][Cl], synthesis temperature and duration. IL played the role of morphology-directing agent given...
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Efficiency of exciton splitting in organic photovoltaic cells within EQE spectrum
PublicationThe paper presents a procedure of estimating the efficiency of exciton splitting at ED/EA interface. The procedure consists in evaluation of splitting of excitons into electron-hole pairs on the basis of the external quantum efficiency spectra of planar cells and spectra of absorbance of active organic layers. The fitting parameters are the exciton splitting probabilities at ED/EA interface. The presented procedure was applied...
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Reactive deposition of TiNx layers in a DC-magnetron discharge
PublicationTiNx layers have been deposited in 'balanced mode' and 'unbalanced mode' of a reactive DC-magnetron plasma (carrier gas argon, reactive gas nitrogen) under different conditions. Discharge power and reactive gas flow have been varied. The layers have been examined by X-ray photoelectron spectroscopy (XPS), X-ray reflectometry (XR), and spectroscopic ellipsometry (SE). The results of the layer analyses were combined with plasma investigations...
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Influence of hydrochloric acid concentration and type of nitrogen source on the electrochemical performance of TiO2/N-MoS2 for energy storage applications
PublicationIn this work, nitrogen-doped molybdenum sulfide was directly deposited on titanium dioxide nanotubes substrate (TiO2/N-MoS2) during hydrothermal synthesis. The study focuses on the influence of hydrochloric acid concentration used for the synthesis, with the results indicating its essential role in thioacetamide hydrolysis and thus in the effectiveness of the N-MoS2 deposition. The electrode material itself is characterized by...
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Tailoring a low-energy ball milled MnCo2O4 spinel catalyst to boost oxygen evolution reaction performance
PublicationThe development of cost-efficient oxygen evolution reaction (OER) catalysts is one of the most important tasks facing modern techniques for hydrogen production. In this work, for the first time, a low-energy ball milling process of MnCo2O4 (MCO) spinel powders, with a mechanical modification time exceeding 1 day was used. After 6 days of ball-milling, the obtained overpotential of the electrocatalyst reached the value of 375 mV...
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Semi-transparent ordered TiO2 nanostructures prepared by anodization of titanium thin films deposited onto the FTO substrate
PublicationIn a significant amount of cases, the highly ordered TiO2nanotube arrays grow through anodic oxidationof a titanium metal plate immersed in electrolyte containing fluoride ions. However, for some practicalapplications, e.g. solar cells or electrochromic windows, the semi-transparent TiO2formed directly onthe transparent, conductive substrate is very much desired. This work shows that high-quality Ti coatingcould be formed at room...
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Stannates, titanates and tantalates modified with carbon and graphene quantum dots for enhancement of visible-light photocatalytic activity
PublicationMost efforts in heterogeneous photocatalysis are focused on development of new and stable photoactive materials efficient in degradation of various pollutants under visible-light irradiation. In this regard, the wide-bandgap perovskite semiconductors, i.e., SrTiO3 (titanate), SrSnO3 (stannate) and AgTaO3 (tantalate), were prepared by a solvothermal method, and then modified with carbon quantum dots (CQDs) or graphene quantum dots...
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Paweł Możejko dr hab.
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