نوع مقاله : مقاله پژوهشی
نویسندگان
گروه مهندسی شیمی، دانشکده مهندسی، دانشگاه کردستان، سنندج، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
In the present study, the effect of structural decoration of titania nanofibers with different amounts of ceria-alumina composite nanoparticles on photocatalytic properties and efficiency in the treatment process of water contaminated with methyl orange dye pollutant was studied and investigated. For this purpose, composite nanoparticles comprising 30 wt.% of ceria were initially synthesized using the impregnation method, and then varying amounts of these nanoparticles (0, 1, 2.5, and 5 wt.%) were dispersed into the titania precursor solution, and then they were electrospun to prepare titania nanofibers decorated with nanoparticles. Ceria-alumina nanoparticles and optimized composite nanofibers were characterized by XRD, FESEM/EDX and PL analyses. The formation of ceria and alumina crystalline phases and the identification of oxygen, aluminum and cerium elements in XRD and EDX analyses confirmed the authenticity of the claimed synthesis of ceria-alumina composite nanoparticles. The characterization results indicate that although the structural decoration of titania nanofibers with an appropriate amount of ceria-alumina nanoparticles does not cause a noticeable change in the crystalline structure of titania, but it reduces the recombination rate of charge carriers. The non-uniformity in the cross section of nanofibers as well as the identification of aluminum and cerium elements confirmed the presence of ceria-alumina nanoparticles in the structure of titania-based nanofibers. According to the performance results, it was found that structural decoration with nanoparticles increases the adsorption capacity of titania nanofibers. Furthermore, 1 wt.% was selected as the optimal amount of ceria-alumina nanoparticles for structural decoration of nanofibers. This photocatalyst eliminated approximately 74% of the dye pollutant within 2 h irradiation of UV light. With the increase in the loading content of nanoparticles, the removal efficiency of nanofibers gradually diminishes, which can be attributed to the decrease in the number of accessible active sites and the obstruction of titania sites with nanoparticles, as well as possibly the increase in the recombination rate of electron-hole pairs. Examining different kinetic models for optimally decorated nanofibers revealed that the results of photodecomposition of methyl orange are most consistent with the first-order kinetic model (R2>0.99).
کلیدواژهها [English]
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