Environmental remediation using silver nanoparticles biosynthesized from agro waste banana and pineapple peels

Synthetic dyes in industrial wastewater pose significant environmental and health risks due to their persistence, toxicity, and resistance to conventional treatment methods. Green synthesis of silver nanoparticles (AgNPs) using agro-waste extracts provides an eco-friendly and sustainable approach for producing efficient nanocatalysts for dye degradation. Although banana peel extract (BPE) and pineapple peel extract (PPE) have been individually explored for AgNPs biosynthesis, systematic direct comparisons under identical conditions are still limited. This study addresses this gap by evaluating BPE and PPE as reducing and stabilizing agents for AgNPs production and assessing their catalytic performance in methylene blue (MB) and methyl orange (MO) degradation. Phytochemical analysis showed markedly higher total phenolic content in BPE (8.65 ± 0.51 mg GAE/g dry peel) compared to PPE (0.253 ± 0.01 mg GAE/g). Despite this, PPE-derived AgNPs exhibited smaller crystallite sizes (~ 12.3 nm by XRD) and particle sizes (21.6 ± 7.01 nm by FESEM) than BPE-AgNPs (~ 18.7 nm and 30.99 ± 9.47 nm, respectively). Surface plasmon resonance peaks were observed at 430 nm (BPE-AgNPs) and 450 nm (PPE-AgNPs). Comprehensive characterization using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray (EDX) analysis confirmed crystalline face-centered cubic structures, spherical morphology, and the role of hydroxyl, carboxyl, and amine groups from peel phytochemicals in reduction and capping. In the presence of NaBH₄, PPE-AgNPs achieved superior catalytic performance, degrading ~ 95% of MB within 60 min and ~ 88% of MO within 75 min, outperforming BPE-AgNPs (~ 82% and ~ 73%, respectively). Kinetic modeling revealed dye- and precursor-dependent mechanisms, with smaller particle size and enhanced surface accessibility of PPE-AgNPs as the dominant factors over phenolic content. These results demonstrate the potential of pineapple peel waste to produce highly efficient, eco-friendly AgNP nanocatalysts. This work highlights the importance of phytochemical diversity in agro-waste valorization for sustainable wastewater remediation, supporting circular economy principles and UN Sustainable Development Goals (SDGs 6, 9, 12, and 13).Clinical trial Not applicable.