Ultrasonic-assisted photocatalytic degradation of various organic contaminants using ZnO supported on a natural polymer of sporopollenin

Parisa Yekan Motlagh; Behrouz Vahid; Sema Akay; Berkant Kayan; Yeojoon Yoon; Alireza Khataee

doi:10.1016/j.ultsonch.2023.106486

Ultrasonic-assisted photocatalytic degradation of various organic contaminants using ZnO supported on a natural polymer of sporopollenin

Ultrason Sonochem. 2023 Aug:98:106486. doi: 10.1016/j.ultsonch.2023.106486. Epub 2023 Jun 16.

Authors

Parisa Yekan Motlagh¹, Behrouz Vahid², Sema Akay³, Berkant Kayan³, Yeojoon Yoon⁴, Alireza Khataee⁵

Affiliations

¹ Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-1647, Tabriz, Iran.
² Department of Chemical Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran.
³ Department of Chemistry, Arts and Science Faculty, Aksaray University, Aksaray, Turkey.
⁴ Department of Environmental and Energy Engineering, Yonsei University, Wonju, Republic of Korea. Electronic address: yajoony@yonsei.ac.kr.
⁵ Research Laboratory of Advanced Water and Wastewater Treatment Processes, Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, 51666-1647, Tabriz, Iran; Department of Environmental Engineering, Gebze Technical University, 41400 Gebze, Turkey. Electronic address: a_khataee@tabrizu.ac.ir.

Abstract

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.

Keywords: Nanocatalyst; Organic pollutants; Sonophotocatalytic process; Sporopollenin; Zinc oxide.