Optimization of Green Synthesis Parameters of Silver Nanoparticles with Factorial Design for Dye Removal

Abstract

In this study production of silver nanoparticles (AgNPs) from collard greens were optimized by the design of experiments (DOE). A 24 full factorial design was employed to evaluate the effects on two responses. The optimized values for AgNP production were 1:7 leaf to water, 1:4 extract to AgNO3, 5 molar AgNO3, and a leaf size of <1 mm. For dye removal efficiency, the optimized values were changed to 1:15 of leaf to water and 1:10 of extract to AgNO3, while the other two parameters remained the same. SEM (scanning electron microscopy) showed that optimizing the process for dye removal led to smaller AgNP production with increased surface area, resulting in higher absorbency. ANOVA (analysis of variance) tables were used to interpret each parameter's main and effects on interaction. Additionally, reaction rate kinetics were estimated, and dye removal showed a slightly higher R-square of pseudo second-order than NP production, which fits the pseudo first-order reaction model.