Enhanced Photocatalytic Degradation of Malachite Green Dye Using Silver–Manganese Oxide Nanoparticles

Abstract

Efficient and excellent nanoparticles are required for the degradation of organic dyes in photocatalysis. In this study, silver–manganese oxide nanoparticles (Ag-Mn-NPs) were synthesized through a wet chemical precipitation method and characterized as an advanced catalyst that has enhanced photocatalytic activity under sunlight irradiation. The nanoparticles were characterized using scanning electron microscopy (SEM), XRD, UV–vis light spectra, and energy-dispersive X-ray (EDX) spectroscopy, revealing their spherical and agglomerated form. The EDX spectra confirmed the composition of the nanoparticles, indicating their presence in oxide form. These bimetallic oxide nanoparticles were employed as photocatalysts for the degradation of malachite green (MG) dye under sunlight irradiation in an aqueous medium. The study investigated the effects of various parameters, such as irradiation time, catalyst dosage, recovered catalyst dosage, dye concentration, and pH, on the dye’s photodegradation. The results showed that Ag-Mn oxide nanoparticles exhibited high photocatalytic activity, degrading 92% of the dye in 100 min. A longer irradiation time led to increased dye degradation. Moreover, a higher catalyst dosage resulted in a higher dye degradation percentage, with 91% degradation achieved using 0.0017 g of the photocatalyst in 60 min. Increasing the pH of the medium also enhanced the dye degradation, with 99% degradation achieved at pH 10 in 60 min. However, the photodegradation rate decreased with increasing dye concentration. The Ag-Mn oxide nanoparticles demonstrate excellent potential as a reliable visible-light-responsive photocatalyst for the efficient degradation of organic pollutants in wastewater treatment.

Nanolayered Structures and Nanohybrids Based on a Ternary System Co/Ti/Zn for Production of Photo-Active Nanocomposites and Purification of Water Using Light

“…These oxidizing agents could convert the hydrocarbons to carbon dioxide and water, as seen in Scheme 1. The theoretical basis [1,3,[20][21][22][23][24][25][26][27][28][29][30] for the mechnism of photocatalysts depends on the separation processes between electrons and holes when exposed to UV light, as seen in Scheme 1. Due to the photons of the UV light, the electrons are excited in the valence band and jump to the conduction band, leaving holes in the valence band, as shown in Equation ( 1).…”

“…In 2023, many researchers [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 ] employed nanocomposites and nanohybrids to be used as effective photocatalysts and harnessing light radiation for breaking down different kinds of dyes in contaminated wastewater such as Malachite Green, Rhodamine B, Methyl Orange, and Congo red in addition to food and juices dyes. In these processes, the highly reactive hydroxyl ( • OH) radicals are generated to convert water pollutants to benign end products, such as carbon dioxide and water.…”