Greener approach for the synthesis of Ag decorated ZnO–CeO2 nanostructure using Moringa oleifera LE and its investigation as photocatalyst for degradation of ciprofloxacin and methylene orange

Abstract

Green synthesis of silver decorated ZnO–CeO2 nanostructure (Ag@ZnO–CeO2 NS) mediated Moringa oleifera LE and its photocatalytic potential against ciprofloxacin antibiotic and Methylene orange dye under sunlight. The synthesized ZnO–CeO2 and Ag@ZnO–CeO2 NS were characterized using X-ray diffraction (XRD) analysis. The crystallite size and crystallinity were calculated to 74 nm and 89% respectively using XRD analysis. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of Ag, Zn, Ce and oxygen vacancies in green synthesized Ag@ZnO–CeO2 NS. Also, PL spectroscopy analysis showed the oxygen vacancies due to defects in nanostructure. The bandgap of prepared nanostructure was calculated to 2.0 eV by UV–visible spectroscopy analysis. Ag@ZnO–CeO2 NS average particles size was evaluated to 40 nm by scanning electron microscopy (SEM) analysis and energy-dispersive X-ray (EDX) analysis confirmed the presence of Ag, Zn and Ce in nanostructure. The Ag@ZnO–CeO2 NS showed an excellent Brunauer-Emmett-Teller (BET) surface area of 165 m2g-1 and 15 nm of pore diameter. Moreover, Fourier transform infrared (FTIR) spectroscopy was used to analyze chemical bonding and interaction and RAMAN spectroscopy confirmed the presence of oxygen vacancies. The thermal decomposition and heat flow was accessed by thermogravimetric analysis (TGA) and Differential scanning calorimetry (DSC) The Ag@ZnO–CeO2 NS demonstrated great potential for environmental remediation which offered effective approach for the removal of Ciprofloxacin antibiotic and Methylene orange dye from wastewater with 74% and 85% photocatalytic activity respectively. The stability of catalyst after 5 cycles of reusability was evaluated by XRD analysis which showed the crystalline structure. This research contributes to the development of advanced nanomaterials with improved photocatalytic properties and the removal of emerging contaminants.