In situ and bio-green synthesis of silver nanoparticles immobilized on zeolite as a recyclable catalyst for the degradation of OPDs

Abstract

In this study, silver nanoparticles (Ag-NPs) were synthesized using a green and biologically inspired approach by utilizing reducing compounds from Thyme plant leaves. Zeolite was used to immobilize the synthesized Ag-NPs (Ag@Z). The modified Zeolite served as a catalyst for the reduction reaction of various organic pollutant dyes (OPDs) including 4-nitrophenol (4-NP), 4-nitroaniline (4-NA), methylene blue (MB), and methyl orange (MO) with sodium borohydride. The degradation of OPDs was monitored by measuring changes in their maximum absorption wavelength intensity. A thorough examination of multiple parameters (catalyst, silver and sodium borohydride dosage, yield degradation, and reaction time) was carried out to identify the optimized conditions for the degradation of OPDs. The results showed that the Ag@Z catalyst achieved an efficiency of over 93% in less than 10 min for the degradation of OPDs. The recoverability and reusability of the catalyst were examined, revealing a partial loss in efficiency after four recovery stages. Structural analysis using XRD, SEM, and TEM techniques confirmed the characteristics and morphology of the synthesized catalyst.

Sustainable conversion of polyethylene plastic bottles into terephthalic acid, synthesis of coated MIL-101 metal–organic framework and catalytic degradation of pollutant dyes

“…Comparison of Entries 6 and 7 reveals that while Ag 3 PO 4 has limited capability in degrading COPs, the addition of NaBH 4 greatly enhances reaction efficiency and degradation rate. Sodium borohydride is thought to induce the reduction of silver ions and formation of Ag nanoparticles, enabling them to effectively catalyze the degradation of the desired COP compounds 9 , 64 . Considering our primary objective of conducting environmentally friendly processes and degrading environmental pollutants, we have overlooked application of Ag-MIL-101 composite as catalyst for the COP degradation reaction in the presence of NaBH 4 .…”

“…Water treatment involves physicochemical and biological methods 8 , 9 . Advanced technologies like adsorption, advanced oxidation (by efficient materials such as peroxodisulfate (PDS), peroxomonosulfate (PMS) or hydrogen peroxide (H 2 O 2 )), flocculation, and filtration, along with innovative approaches like microbiological and electro-catalytic methods, have gained attention for water treatment 10 – 15 .…”

“…Silver nanoparticles (Ag NPs) stand out due to easy synthesis, reactivity, and affordability. However, their tendency to aggregate limits catalytic efficiency 9 . Also, silver MOFs offer high biocompatibility, biodegradability, and antibacterial potential, making them valuable for antibacterial treatments.…”

“…With lower cytotoxicity and superior stability compared to other metals, silver is utilized in drug delivery, medical imaging, diagnostics and water treatment. To date, researchers have documented numerous studies exploring the application of silver metal in both water treatment methods and the catalytic reduction of COPs 9 , 41 , 51 – 53 .…”

Optimization of methyl orange decolorization by bismuth(0)-doped hydroxyapatite/reduced graphene oxide composite using RSM-CCD

“…This is due to the reaction time between the synthesized catalyst and MO dye affecting the saturation state of the Bi/HAp-rGO surface. With the increase of reaction time, MO molecules will interact more with the reaction sites on the catalyst surface, resulting in increased decolorization efficiency of MO (Al-Ansari et al 2024 ; Zhou et al 2024 ). It was observed that the maximum decolorization efficiency of MO reached its maximum in about 3 min and did not show a significant increase at later levels.…”