سنتز نانوذرات اكسيدفلزي دوستدار محيط زيست و كاربرد آن‌ها براي حذف آلاينده‌هاي آلي

Synthesis of Ecofriendly Metal Oxide Nanoparticles an‎d Their Applications for Removal of Organic Pollutants

شيمي آلي و پليمر

This study employed efficient an‎d environmentally friendly approaches consistent with the principles of green chemistry for the synthesis of CoAl2O4-based nanocomposites. In the first part, the CoAl2O4@ZnO nanocomposite was synthesized via a green sol–gel method using almond gum as a biological agent. The crystal structure, surface characteristics, morphology, an‎d optical properties of the synthesized nanocomposite were investigated using XRD, BET, FESEM, TEM, EDX, an‎d UV–Vis DRS techniques. The XRD results confirmed the formation of cubic spinel CoAl2O4 an‎d hexagonal ZnO phases. The nanocomposite exhibited a specific surface area of 40 m² g-¹ an‎d a ban‎d-gap energy of 3.0 eV. Its photocatalytic performance was eva‎luated for the degradation of tetracycline under visible-light irradiation, an‎d 93% degradation was achieved within 45 min. Reactive species scavenging experiments demonstrated the predominant contribution of hydroxyl radicals (•OH) to the photocatalytic degradation process. Furthermore, LC–MS analysis confirmed the formation of intermediate compounds along the tetracycline degradation pathway. The nanocomposite maintained its photocatalytic performance over five consecutive cycles, with only a 3% decrease in activity, demonstrating its good stability an‎d reusability. In the second part, the CoAl2O4@CdO nanocomposite was synthesized via a green sol–gel method using almond gum as a natural stabilizing agent. The synthesized nanocomposite was characterized in terms of its structural, morphological, surface, an‎d optical properties. The results indicated that the nanocomposite consisted of spherical nanoparticles with an average size of approximately 30–35 nm, a specific surface area of 32 m² g-¹, an‎d a ban‎d-gap energy of 1.75 eV. Its photocatalytic activity was eva‎luated for the degradation of ciprofloxacin under visible-light irradiation, achieving 91% degradation within 45 min. Reactive species scavenging experiments confirmed the predominant role of hydroxyl radicals (•OH) in the degradation process. The nanocomposite also exhibited good photocatalytic stability over five consecutive cycles. The enhanced photocatalytic performance was attributed to the synergistic interaction between CoAl2O4 an‎d CdO, improved utilization of visible-light irradiation, an‎d suppressed charge-carrier recombination.

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سعيد تقوي فردود

171770