Zeolite omega-confined silver nanoparticles AgNPs for antibacterial activities and catalytic reduction of organic contaminants

Dyes have a significant impact on the environment, particularly in industrial sectors such as textile and food. One of the fastest reactions to reduce the toxicity of these pollutants is the reduction of dyes. This research employed a straightforward and efficient approach to confine omega zeolites with various concentrations of silver nanoparticles AgNPs (1, 2, 3, and 4 %). The resulting solids were used as catalysts to reduce methylene blue (MB), orange G (OG), methyl orange (MO) and 4-nitrophenol (4-NP) in a simple and binary system. It was found that AgNPs can be obtained at ultrafine sizes between 2 and 6 nm, with a high level of dispersibility on the zeolite surface. Both systems showed that the catalyst with a high AgNPs content was the most effective and selective with MB dye. The rate constant K_app values (for a simple system) varied in the following sequence: 0.590 s⁻¹, 0.0086 s⁻¹, 0.0046 s⁻¹, and 0.003 s⁻¹ for the pollutants (MB), (MO), (OG), (4-NP), respectively. In binary systems containing 4-NP/MB, MO/MB, and OG/MB, the zeolite confined with 4 % AgNPs. Reusing the catalyst ZO(4 %) in several cycles showed good results in terms of conversion and stability. AgNPs-confined zeolite omega showed the most marked antibacterial effects, with inhibition zones of 36 mm and 31 mm achieved for Escherichia coli E.c and Pseudomonas aeruginosa P.a, respectively. These values were higher than those found with the antibiotic gentamicin.