Green-Synthesized Silver Nanoparticles for Photocatalytic Degradation of Organic Dyes: A Comprehensive Review

Abstract

Silver nanoparticles (AgNPs) have received a lot of interest for their several applications, including their remarkable potential as photocatalysts for organic dye degradation. This review explores the photocatalytic capabilities of silver nanoparticles (AgNPs)—specifically those synthesized via green, eco-friendly methods—in treating synthetic dye-contaminated wastewater. The paper emphasizes the synthesis of AgNPs from various biological substrates, highlighting their economic feasibility, high conductivity, and biocompatibility. The growing concern over the improper disposal of persistent, non-biodegradable synthetic dyes is addressed by showcasing the role of AgNPs as effective agents for breaking down harmful industrial dyes. Key target dyes investigated include methyl orange, congo red, nitrophenol, methylene blue, and malachite green, with performance data reflecting the success of AgNPs from different biological sources. The review outlines the mechanisms of photocatalytic degradation facilitated by these nanoparticles, illustrating how they convert toxic dyes into less hazardous compounds. It also examines the toxicity of AgNPs themselves and strategies for their environmental remediation. Lastly, a comparative analysis of multiple biological substrates is presented to guide the selection of optimal sources for enhanced photocatalytic efficiency and sustainable wastewater treatment solutions.

Keywords: photocatalytic degradation, Silver nanoparticles (AgNPs), Green synthesis, Biogenic nanoparticles, Nanoparticle toxicity