Green Synthesis of Silver Nanoparticles Using Acacia ehrenbergiana Plant Cortex Extract for Efficient Removal of Rhodamine B Cationic Dye from Wastewater and the Evaluation of Antimicrobial Activity

Silver nanoparticles(Ag-NPs) exhibit vast potential in numerousapplications, such as wastewater treatment and catalysis. In thisstudy, we report the green synthesis of Ag-NPs using Acacia ehrenbergiana plant cortex extract to reducecationic Rhodamine B (RhB) dye and for antibacterial and antifungalapplications. The green synthesis of Ag-NPs involves three main phases:activation, growth, and termination. The shape and morphologies ofthe prepared Ag-NPs were studied through different analytical techniques.The results confirmed the successful preparation of Ag-NPs with aparticle size distribution ranging from 1 to 40 nm. The Ag-NPs wereused as a heterogeneous catalyst to reduce RhB dye from aqueous solutionsin the presence of sodium borohydride (NaBH4). The resultsshowed that 96% of catalytic reduction can be accomplished within32 min using 20 mu L of 0.05% Ag-NPs aqueous suspension in 100 mu L of 1 mM RhB solution, 2 mL of deionized water, and 1 mL of10 mM NaBH4 solution. The results followed a zero-orderchemical kinetic (R (2) = 0.98) with reactionrate constant k as 0.059 mol L-1 s(-1). Furthermore, the Ag-NPs were used as antibacterialand antifungal agents against 16 Gram-positive and Gram-negative bacteriaas well as 1 fungus. The green synthesis of Ag-NPs is environmentallyfriendly and inexpensive, as well as yields highly stabilized nanoparticlesby phytochemicals. The substantial results of catalytic reductionsand antimicrobial activity reflect the novelty of the prepared Ag-NPs.These nanoparticles entrench the dye and effectively remove the microorganismsfrom polluted water.