Green synthesis of antibacterial bimetallic Ag–Cu nanoparticles for catalytic reduction of persistent organic pollutants

In this report, we used facile, active, cheap, re-usable and high surface area catalyst for the synthesis of green substrate turmeric (Curcuma longa) powder support mixed silver copper (Ag–Cu/TP), copper nickel (Cu–Ni/TP) and nickel silver (Ni–Ag/TP) nanoparticles. For nanoparticles synthesis the turmeric powder were kept in 0.5 M aqueous metal salt solution and then treated with aqueous solution of NaBH₄ for in situ conversion of metal ions into their nanoparticles. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray spectroscopy (EDX) confirm the formation of nanomaterials. Silver mix nanoparticles show excellent activities against Escherichia coli (E. coli). The prepared nanoparticles were employed for the reduction of fluoroquinolone antibiotics ciprofloxacin (CIP) and levofloxacin (LVO) as well as for Methyl orange (MO), Congo red (CR), Methylene blue (MB) and Rhodamine B (RhB) dyes. Ag–Cu/TP catalyst showed excellent catalytic activity for the reductive transformation of antibiotics as well as for the remediation of MO, CR, MB and RhB dyes. The rate constants of pseudo first order reaction for CIP and LVO were 1.27 × 10⁻³ s⁻¹ and 1.52 × 10⁻³ s⁻¹ respectively. Ag–Cu/TP also showed excellent recyclability till the 5th cycle for MO reduction. The abundant nature, low cost, excellent reusability and effective catalytic degradation make Ag–Cu/TP suitable candidates for the reduction of organic molecules.