How Temperature and Photosynthetically Active Radiation Impact the Green Synthesis of Silver Nanoparticles Using Aqueous Extracts of Mentha Leaves?

Abstract

Green synthesis highlights sustainable methods to produce silver nanoparticles (AgNPs). Here, extracts from fresh and lyophilized Mentha leaves produced AgNPs when performing reactions in the dark at 25ºC or 75ºC; also under photosynthetically active radiation (PAR) at 25ºC aiming to compare hydrothermal and photochemical methods. AgNPs formation was spectrophotometrically monitored and characterized by dynamic light scattering (DLS) and Zeta potential (ZP). The most polydisperse AgNPs suspension was synthesized at 25ºC (dark), presenting polydispersity index (PdI) of 0.574±0.061, and exhibited the lowest hydrodynamic diameter (HD) of 44.34±1.60 nm. In contrast, the highest HD was 80.15±2.88 nm to AgNPs produced at 25ºC with PAR which exhibited ZP of -27.8±0.7 mV. The lowest polydisperse suspension was produced at 75ºC (dark), presenting PdI of 0.369±0.009 and ZP of -12.8±0.6 mV. Concluding, we compared reliable green synthesis’ methods to determine which would efficiently produce AgNPs using Mentha leaves.