Application of Green Synthesized Silver Nanoparticles for Dye Wastewater Treatment

Abstract

A facile one-pot synthesis of silver nanoparticles (AgNPs) was achieved using the ethanolic extract of Cavendish banana florets as source of reducing agents for the conversion of Ag+ to Ag. The appearance of surface plasmon resonance peak between 410–435 nm in the UV Vis spectra confirmed the formation of AgNPs. The effects of different reaction conditions on the size and concentration of AgNPs were evaluated. The optimum conditions identified were pH 7 at 80 °C. Transmission electron microscopy (TEM) revealed spherical AgNPs with a mean particle size of 13.55 nm. On the other hand, energy-dispersive X-ray (EDX) analysis confirmed the presence of silver (Ag) as the bulk element (87.25%). Other elements such as carbon (C) and oxygen (O) are attributed to the capping agents of AgNPs which agrees with the results in the Fourier-transform infrared spectroscopy (FTIR) analysis. The optimized AgNPs were used for dye degradation using methyl orange (MO) as the model dye under acidified conditions. The maximum MO dye degradation of 96.07% and 77.32% at pH 1.5 and 2 were achieved after 10 min and 1320 min, respectively. This highlights the potential use of green-synthesized AgNPs for dye wastewater treatment.