Catalysis of diverse azo compounds using Eucommia ulmoides phytochemicals reduced and stabilized nanosilver

Abstract

Biological macromolecules, encompassing plant phytochemicals, biopolymers, and polysaccharides, are validated for simultaneous metal cation reduction and their stabilization for metal nanoparticles (NPs) through green synthesis. The application of these biosynthesized NPs in azo dye catalysis is established but limited to specific model compounds. The fundamental question emerges: Do these NPs uniformly catalyze across diverse azo dyes, disregarding structural complexity, azo bond count, side chain functional groups, molecular weight (Mw) variations, water solubility levels, ionic nature, and dye class (reactive or acid)? To comprehensively investigate, nine azo compounds meeting the aforementioned criteria were chosen for catalysis using synthesized silver NPs (AgNPs). This synthesis employs Eucommia ulmoides bark extract (EUBE) within green chemistry principles. The synthesized AgNPs, predominantly spherical and nano-sized (5–14 nm) with uniform distribution and a highly crystalline surface, are securely stabilized by a thin membrane of EUBE phytochemicals, exhibiting no agglomeration. It yields outstanding catalytic performance on a diverse group of azo dyes, achieving up to 100% degradation within 1–16 min. The reaction adheres to a pseudo-kinetic first-order mechanism. This systematic approach provides a comprehensive insight into the catalytic prowess of AgNPs, elucidating their potential across a diverse range of azo compounds, thereby advancing knowledge in the field.