Abstract
Controlling the size and distribution of palladium nanoparticles (Pd NPs) during green synthesis by varying one process parameter at a time is both time-consuming and resource-intensive; particularly when using plants that serve as food sources, have high economic and industrial value, or are region-specific with limited availability. This study addresses these limitations by utilizing Sida Acuta (SA) leaf extract, a sustainable and widely available alternative, as a reducing and stabilizing agent for Pd NP synthesis. Taguchi-Grey Relational Analysis (GRA) was employed to optimize key synthesis parameters: reaction temperature, extract concentration, and reaction time. An L9 Taguchi orthogonal array was designed for experimental runs, and grey relational grade was used for the process optimization. Analysis of variance (ANOVA) was used to evaluate each factor's contribution at a 95% confidence level. The synthesis was visually confirmed by the color change of the reaction mixture and the disappearance of the UV-visible spectrum band of Pd²⁺ ions. FTIR analysis identified hydroxyl (O-H) and aromatic (C=C) functional groups involved in stabilizing the Pd NPs. SEM and XRD analyses revealed agglomerated, nearly spherical nanoparticles with a face-centered cubic structure and an average crystallite size of ~10 nm. Taguchi-GRA optimization achieved a hydrodynamic diameter of 62.5 nm and a PDI of 0.232 with parameters of 10 mg/mL extract concentration, 30 minutes reaction time, and 60°C temperature. ANOVA results showed extract concentration had the highest impact. This optimized, eco-friendly approach offers an efficient method for producing Pd NPs with controlled properties, enhancing their potential for diverse industrial applications.

Key words: Palladium nanoparticles, synthesis, Grey Rational Analysis, Taguchi method, Sida Acuta leaf extract