Synthesis and Magnetic and Optical Properties of Novel Fe@ZSM-5 CompositesстатьяИсследовательская статья
Статья опубликована в журнале из списка Web of Science и/или Scopus
Авторы:
Zvereva Irina A.,
Pankratov Denis A.,
Zemstova Elena G.,
Kudymov Vladimir K.,
Samadov Azamat,
Kurnosenko Sergey A.,
Kirichenko Sergey O.,
Shelyapina Marina G.,
Petranovskii Vitalii
Аннотация:Alkaline treatment in 0.2 and 0.4 M NaOH solutions successfully generated controlled mesoporosity into ZSM-5 (Zeolite Socony Mobil-5) zeolite, resulting in average mesopore diameters of approximately 15 and 25 nm, respectively, while preserving the crystalline structure of the zeolite framework. Parent ZSM-5 and its mesoporous derivatives obtained by desilication were used to prepare (Fe species)@(zeolite matrix) composites. The synthesis was carried out by co-precipitating Fe2+/Fe3+ ions onto both parent and desilicated ZSM-5 matrices under oxygen-free conditions. Comprehensive characterization by X-ray diffraction, scanning electron microscopy, N2 adsorption, vibrating-sample magnetometry, 57Fe Mössbauer spectroscopy, and diffuse reflectance UV–Vis spectroscopy revealed that the degree of introduced mesoporosity dramatically influences the size, dispersion, phase composition, and oxidation state of the iron-containing nanospecies. On purely microporous ZSM-5, relatively large (~15 nm) partially oxidized magnetite nanoparticles are formed predominantly on the external surface, exhibiting superparamagnetism at room temperature (Mₛ = 11 emu/g) and a band gap of 2.12 eV. Increasing mesoporosity leads to progressively smaller and more highly dispersed iron(III) oxo/hydroxo clusters with significantly lower blocking temperatures and reduced magnetization (down to 0.7 emu/g for Fe@ZSM-5_0.4). All composites display strong visible-light absorption confirming their potential as magnetically separable visible-light-driven photocatalysts for environmental remediation.
