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  • Küçük Resim
    Öğe
    Palladium nanoparticles supported on biochar/graphitic carbon nitride as a heterogeneous catalyst for pharmaceutical degradation
    (Elsevier Ltd, 2024) Yekan Motlagh, Parisa; Vahid, Behrouz; Karimpour, Deniz; Babazadeh, Negar; Kayan, Berkant; Baran, Talat
    Sonocatalysis is a promising method for degrading organic pollutants in aqueous media. However, practical applications require the development of low-cost, green, and efficient sonocatalysts. This study investigated the removal of pharmaceutical compounds, such as tetracycline (TC), from water and wastewater via ultrasound (US)-based decomposition by Pd nanoparticles protected on biochar/graphitic carbon nitride (Pd@BC/g-C3N4). The constituents and characteristics of the catalysts were evaluated, and BC/g-C3N4 and Pd@BC/g-C3N4 were found to have bandgaps of 2.61, and 2.21 eV, respectively. Furthermore, the Pd@BC/g-C3N4 nanocomposite was confirmed to consist of Pd nanoparticles uniformly distributed on BC/g-C3N4. Pd@BC/g-C3N4 attained a degradation performance of 94.23 % after 120 min under the optimum conditions ([TC]0 = 10 mg/L, [Pd@BC/g-C3N4] = 0.03 g/L, and pH 6), whereas the degradation efficiency was only 78.33 % with BC/g-C3N4. The sonocatalytic activity did not decrease significantly during reusability experiments, demonstrating the high stability of the Pd@BC/g-C3N4 structure. The hydroxyl radicals (•OH) production during the sonocatalytic degradation of TC via the US/Pd@BC/g-C3N4 process was confirmed using photoluminescence measurements and scavenging experiments with o-phenylenediamine. Gas chromatography-mass spectrometry analysis of the TC degradation intermediates revealed short-chain compounds, suggesting considerable progress toward mineralization during the sonocatalytic process. Thus, Pd@BC/g-C3N4 has the potential as an efficient heterogenous sonocatalyst for wastewater remediation.
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    Ultrasonic-assisted photocatalytic degradation of various organic contaminants using ZnO supported on a natural polymer of sporopollenin
    (Elsevier B.V., 2023) Yekan Motlagh, Parisa; Vahid, Behrouz; Akay, Sema; Kayan, Berkant; Yoon, Yeojoon; Khataee, Alireza
    Water resource pollution by organic contaminants is an environmental issue of increasing concern. Here, sporopollenin/zinc oxide (SP/ZnO) was used as an environmentally friendly and durable catalyst for sonophotocatalytic treatment of three organic compounds: direct blue 25 (DB 25), levofloxacin (LEV), and dimethylphtalate (DMPh). The resulting catalyst had a 2.65 eV bandgap value and 9.81 m2/g surface area. The crystalline structure and functional groups of SP/ZnO were confirmed by X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR) analyses. After 120 min of the sonophotocatalysis, the degradation efficiencies of DB 25, LEV, and DMPh by SP/ZnO were 86.41, 75.88, and 62.54%, respectively, which were higher than that of the other investigated processes. The role of reactive oxygen species were investigated using various scavengers, enhancers, photoluminescence, and o-phenylenediamine. Owing to its stability, the catalyst exhibited good reusability after four consecutive cycles. In addition, the high integrity of the catalyst was confirmed by scanning electron microscopy (SEM), XRD, and FTIR analyses. After four consecutive examinations, the leaching of zinc in the aqueous phase was < 3 mg/L. Moreover, gas chromatography-mass spectrometry (GC–MS) analyses indicated that the contaminants were initially converted into cyclic compounds and then into aliphatic compounds, including carboxylic acids and animated products. Thus, this study synthesized an environmentally friendly and reusable SP/ZnO composite for the degradation of various organic pollutants using a sonophotocatalytic process.