ENHANCED PLASMONIC ACTIVITY IN AG-MODIFIED MnO₂/SiO₂ SPHERES FOR RAPID MITIGATION OF ANTIBIOTIC RESISTANCE

Ternary SiO 2 /MnO 2 –Ag composites were synthesized and evaluated as photocatalysts for the degradation of antibiotic Tetracycline (TC) in aqueous solution. Morphological and optical analyses demonstrated that MnO 2 nanoparticles were efficiently tailored on the adsorbed sites of SiO 2 spheres, while plasmonic metallic silver nanoparticles (Ag NPs) were coated on the surface of the SiO 2 /MnO 2 composite. The SiO 2 /MnO 2 –Ag ternary composition, as obtained, exhibited remarkable photocatalytic activity in the degradation of TC (91.3%) antibiotic, surpassing the performance of individual SiO 2 , MnO 2 , and SiO 2 /MnO 2 catalysts. This higher photocatalytic efficiency is primarily attributed to two key factors: enhanced photo-absorption capabilities facilitated by the presence of Ag nanoparticles, and the substantial mitigation of photoinduced electron and hole recombination through efficient charge transfer at the Schottky junction. SiO 2 plays a pivotal role by acting as a template that accelerates the separation of electron–hole pairs, while Ag metal serves as an electron sink, thereby bolstering interfacial charge transfer.