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  • Characterization of porous photocatalyst based on ZnO nanoparticles
    Maučec, Darja ...
    Industrial wastewater presents a global environmental problem. Organic dyes are one of the main industrial pollutants as they are used in many industries such as textile, cosmetics, paper and paint ... industry. They are frequently found in industrial wastewater and present environmental hazard due to their toxic, mutagenic and carcinogenic nature. Advanced oxidation processes (AOPs) are alternative methods for the complete degradation of dyes. AOPs are based on the activity of very reactive species, such as hydroxyl radicals, which quickly and nonselectively oxidize a broad range of organic pollutants. Photocatalytic systems, such as a combination of semiconductors and light are one of the AOPs methods. ZnO is a well known semiconductor for the degradation of various organic dyes in the wastewater treatment. With decrease of ZnO particle size to the nanoscale, the surface area and efficiency of catalyst increase. The challenge remaining is a recycling of used photocatalyst. One of possible solution is the immobilization of ZnO nanoparticles on mesoporous silicate supports. ZnO nanoparticles were immobilized in the disordered mesoporous silicate support KIL-2 (denoted xZnO/KIL-2, x = various Zn/Si moral ratios from 0,2 to 0,7) and ordered mesoporous silicate support SBA-15 (denoted xZnO/SBA- 15, x = various Zn/Si moral ratio from 0,2 to 0,7) by using the Schlenk-line. Prepared composites were characterized using X-ray powder diffraction (XRD), nitrogen physisorption, scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), elemental analysis (EDX). Comparing of the SEM images of xZnO/KIL-2 and xZnO/SBA-15 suggests that the morphology of composites does not change compared to pure KIL-2 and SBA-15. The lowangle lowangle XRD patterns of KIL-2 and SBA-15 indicate that the KIL-2 has a disordered mesoporous structure while the SBA-15 has an ordered hexagonal porearrangement (not shown). The XRD patterns of composites recorded at the wide-angle range (5°<O>60°) confirm that ZnO nanoparticles are present in both composites. The adsorption/desorption nitrogen isotherms were used to study the changes in the pore structure of the composites with different ZnO loadings. The presence of the ZnO nanoparticles in KIL-2 and SBA-15 changes the shape of the hysteresis loops. The hysteresis loops of all composites are closing down at lower relative pressure values in comparison topure KIL-2 and SBA-15, which indicates that the pores are partially narrowed with ZnO nanoparticles (not shown).
    Vir: Book of abstracts (Str. 94)
    Vrsta gradiva - prispevek na konferenci
    Leto - 2012
    Jezik - angleški
    COBISS.SI-ID - 5117978

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