Green synthesis and multifunctional properties of Cu/NiO nanocomposites using Commelina benghalensis leaf extract.

ABSTRACT

This study presents the green synthesis and multifunctional properties of Cu/NiO nanocomposites (NCs) fabricated with varying ratios (9010, 8020, and 7030) using Commelina benghalensis leaf extract. X-ray diffraction (XRD) analysis confirmed the polycrystalline nature of the NCs, revealing crystallite sizes of 13.62, 13.22, and 7.14 nm. Scanning electron microscopy (SEM) showed rod-shaped and agglomerated particles with sizes ranging from 17.64 to 22.97 nm. Energy-dispersive X-ray spectroscopy (EDX) verified the elemental composition of copper, nickel, oxygen, and carbon. UV-visible spectroscopy determined the energy band gaps to be in the range of 1.24-1.56 eV. Fourier-transform infrared spectroscopy (FT-IR) indicated the presence of bioactive compounds responsible for the reduction of precursor metal salts. The Cu/NiO NCs exhibited remarkable antimicrobial activity, with the 9010 ratio showing the highest zones of inhibition at 32.76 ± 0.23 mm, 18.66 ± 0.33 mm, and 14.36 ± 0.32 mm against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli, respectively. Additionally, the 7030 Cu/NiO NCs demonstrated superior antioxidant activity, with a radical scavenging efficiency of 83.22%, closely approaching that of ascorbic acid (96.98%). Photocatalytic evaluations revealed that the NCs were highly effective in degrading environmental pollutants, achieving 97.69% degradation of malachite green and 96.52% of congo red under UV light irradiation. The novelty of this work lies in the use of Commelina benghalensis leaf extract as a sustainable and eco-friendly reducing and stabilizing agent for synthesizing Cu/NiO NCs, offering a green alternative to conventional methods. The synergistic effects between Cu and NiO in the different compositions (9010, 8020, and 7030) enhanced the overall antimicrobial and photocatalytic activities, highlighting their potential for environmental remediation applications.