Przeglądaj wg Autor "Leniec, Grzegorz"

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    PozycjaOpen Access
    Antimicrobial properties of pristine and Pt-modified titania P25 in rotating magnetic field conditions
    (Elsevier B.V., 2022-08-01) Paszkiewicz, Oliwia; Wang, Kunlei; Rakoczy, Rafał; Kordas, Marian; Leniec, Grzegorz; Kowalska, Ewa; Markowska-Szczupak, Agata; Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastow 42, Szczecin 71-065, Poland; Institute for Catalysis, Hokkaido University, N21, W10, Sapporo 001-0021, Japan; Institute of Physics, Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Szczecin, al. Piastow 48, Szczecin 70-311, Poland; Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastow 42, Szczecin 71-065, Poland; Institute of Physics, Department of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Szczecin, al. Piastow 48, Szczecin 70-311, Poland; Institute for Catalysis, Hokkaido University, N21, W10, Sapporo 001-0021, Japan; Department of Chemical and Process Engineering, West Pomeranian University of Technology in Szczecin, Piastow 42, Szczecin 71-065, Poland
    Effective and cheap water purification is one of the most important tasks facing humanity. Among various methods of water treatment, heterogeneous photocatalysis is probably most recommended. However, the application of artificial sources of irradiation results in high investment and operating costs. Accordingly, either vis-responsive photocatalysts or different ways of photocatalyst activation should be developed. In the present study, rotating magnetic field (RMF) has been tested to inactivate gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria in the presence of pristine and Pt-modified titania P25 photocatalyst. Liquid cultures of the bacteria have been exposed to the titania and RMF (RMF frequency of 1–50 Hz, RMF magnetic induction of ca. 19.92 mT, 180 min exposure time, temperature of incubation at 37 °C). It has been found that highly active titania photocatalyst might also work in the absence of photoirradiation but under RMF. Moreover, its modification with platinum besides highly improved photocatalytic activity (tested for two model reactions of oxidative decomposition of acetic acid and anaerobic dehydrogenation of methanol under UV/vis irradiation) results in significant enhancement of antimicrobial effect under RMF. Additionally, photocatalysts with larger content of oxidized forms of platinum show higher antimicrobial activity, and thus it is proposed that platinum oxides are more active than zero-valent platinum under RMF. This study provides evidence of antimicrobial effect of titania without photoirradiation, indicating that RMF might efficiently activate photocatalyst.
  • Miniatura
    PozycjaEmbargo
    Electrocatalytic Water Splitting by bifunctional Zircon-doped Borophene
    (Elsevier B.V. , 2025-03-01) Dymerska, Anna G.; Leniec, Grzegorz; Mijowska, Ewa; Department of Nanomaterials Physicochemistry, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Szczecin, Piastów Ave. 45, 71-065 Szczecin, Poland; Department of Nanomaterials Physicochemistry, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Szczecin, Piastów Ave. 45, 71-065 Szczecin, Poland; Department of Nanomaterials Physicochemistry, Faculty of Chemical Technology and Engineering, West Pomeranian University of Technology, Szczecin, Piastów Ave. 45, 71-065 Szczecin, Poland
    Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are crucial for renewable energy technologies such as water splitting. Borophene, a two-dimensional (2D) boron material, has attracted significant interest for its unique electron deficiency and potential applications in energy conversion. However, practical studies on borophene's electrocatalytic performance remain limited. Here, we demonstrate a strategy to enhance the bifunctional electrocatalytic activity in HER and OER of borophene by doping with zirconium compounds. The addition of Zr to boron enhances electrocatalytic properties by improving performance in both OER and HER, achieving overpotentials and Tafel slopes of 252 and 240 mV, 43 and 203 mV/dec, respectively. Additionally, conducting the measurements at 40°C led to achieving the overall water-splitting potential of 1.541 (V vs. RHE). Stability tests over 1000 hours at ±10 mA/cm² highlight the composite's robustness, outperforming Pt/C in HER and matching the stability of RuO₂ in OER. Ex-situ analyses: X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), and X-ray diffraction (XRD) reveal insights into the chemical structure evolution during the electrochemical process. This study not only advances the understanding of borophene's electrocatalytic mechanisms but also paves the way for its application in efficient and sustainable energy technologies.