Anna Gołąbiewska

The Antibacterial and Antifungal Textile Properties Functionalized by Bimetallic Nanoparticles of Ag/Cu with Different Structures

We reported a preparation and characterization of five kinds of impregnation solutions, containing Ag/Cu in the form of bimetallic nanoparticles (alloy and core-shell) as well as ionic species. The cotton-polyester textiles were successfully impregnated during the washing and ironing process by as-prepared solutions to have antibacterial and antifungal properties against to Escherichia coli, Staphylococcus aureus, and Candida albicans. Moreover, we have reported the effect of type of the fabric used and number of washing/impregnation cycles (in a laboratory scale) on the bactericidal and fungicidal activity of obtained textiles. The results indicated that all tested samples after 5, 10, 15, and 20 washing/impregnated cycles exhibited an antimicrobial activity. The antifungal tests showed that only textile impregnated with solutions containing Ag

Synthesis and characterization of monometallic (Ag, Cu) and bimetallic Ag-Cu particles for antibacterial and antifungal applications

In this paper, the experimental studies are concerned with the effect of the synthesis parameters on the formation of monometallic Ag and Cu nanoparticles (NPs). We consider the synthesis strategies verification for the bimetallic core-shell and alloy particles preparation. It was successfully obtained by chemical reduction method. The obtained colloidal solution is characterized by the transmission electron microscopy (TEM) with energy-dispersive X-ray spectroscopy (EDX) data, UV-Vis spectra, particle size distribution, and zeta potential. This work presents a comprehensive overview of experimental studies of the most stable colloidal solutions to impregnate fabrics that will exhibit a bactericidal and fungicidal activity against Candida albicans, Escherichia coli, and Staphylococcus aureus.

Fabrication and photoactivity of ionic liquid–TiO2 structures for efficient visible-light-induced photocatalytic decomposition of organic pollutants in aqueous phase

To investigate the effect of the ionic liquid (IL) chain length on the surface properties and photoactivity of TiO2, a series of TiO2 microspheres have been synthesized via a solvothermal method assisted by 1-methyl-3-octadecylimidazolium chloride ([ODMIM][Cl]) and 1-methyl-3-tetradecylimidazolium chloride ([TDMIM][Cl]). All as-prepared samples were characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), scanning transmission microscopy (STEM) and the Brunauer–Emmett–Teller (BET) surface area method, whereas the photocatalytic activity was evaluated by the degradation of phenol in aqueous solution under visible light irradiation (λ > 420 nm). The highest photoefficiency (four times higher than pristine TiO2) was observed for the TiO2 sample obtained in the presence of [TDMIM][Cl] for a IL to TiO2 precursor molar ratio of 1:3. It was revealed that interactions between the ions of the ionic liquid and the surface of the growing titanium dioxide spheres results in a red-shift of absorption edge for the IL–TiO2 semiconductors. In this regard, the direct increase of the photoactivity of IL–TiO2 in comparison to pristine TiO2 was observed. The active species trapping experiments indicated that O2 •− is the main active species, created at the surface of the IL–TiO2 material under visible-light illumination, and is responsible for the effective phenol degradation.

Characterization of TiO 2 Modified with Bimetallic Ag/Au Nanoparticles Obtained in Microemulsion System

Abstract Titanium dioxide modified with silver-gold bimetallic nanoparticles were prepared by simultaneously formation of Ag/Au and TiO2 nanoparticles in water-in-oil microemulsion system (water/AOT/cyclohexane). Silver nitrate (AgNO3) and tetrachloroauric(III) acid (HAuCl4) were taken as the precursors and sodium borohydride (NaBH4) was used as a reducing agent. The photocatalysts samples were characterized by X-ray powder diffraction (XRD), BET surface area measurements, scanning electron microscopy (SEM) and energy dispersive spectroscopy analysis (EDS). The photocatalytic activity of bimetallic nanoparticles deposited at the TIP-TiO2 surface under visible light irradiation was estimated by measuring the decomposition rate of phenol in aqueous solution. The highest photocatalytic activity was obtained for the photocatalyst containing 1.5 mol % of silver and 0.5 mol % of gold.

Fundamentals of metal oxide-based photocatalysis

Photocatalysis is the change in the rate of reaction caused by light in the presence of a photocatalyst that absorbs light and is involved in the chemical transformation of the reactants. Heterogeneous photocatalysis is based mainly on semiconductor materials such as chalcogenides and metal oxides. Transition metal oxides and mixed oxides are the largest and most important groups of photocatalytic materials. This chapter discusses the photocatalytic reaction mechanisms of metal oxide semiconductors, the semiconductor bandgap structure, and the kinetics of photocatalysis.