Green-synthesized Ag-Ag2S Heterostructures for efficient catalytic remediation of 4-Nitrophenol

• Ag–Ag₂S alloy nanoparticles synthesized via a green route exhibit enhanced catalytic activity. • The specific role of silver in 4-nitrophenol reduction is explicitly investigated. • Enhanced performance is attributed to nanoscale size, morphology, and surface chemistry. • Eco-friendly synthesis offers a sustainable alternative for environmental remediation technologies. The contamination of water bodies by toxic dyes such as 4-nitrophenol (4-NP) presents a critical environmental challenge, driving the need for efficient and sustainable remediation strategies. This study investigates the synthesis and catalytic performance of Ag-Ag 2 S alloy nanoparticles (NPs) prepared via green and conventional chemical routes. Structural and morphological characterizations confirmed the successful formation of the alloy phase through both methods. The green-synthesized nanoparticles exhibited a smaller average size (∼5 nm) compared to chemically synthesized ones (∼23 nm), which contributed to their enhanced catalytic activity. In reduction experiments, the green-synthesized Ag-Ag 2 S NPs achieved a high reduction efficiency of 84% within 6 minutes, significantly outperforming the chemically synthesized NPs, which reached only 54.6% efficiency in 21 minutes. The findings highlight the superior catalytic potential of green-synthesized Ag-Ag 2 S nanoparticles and underscore their promise as eco-friendly nanocatalysts for wastewater treatment applications.