Green synthesis of CuO nanoparticles using Ixora chinesis leaf extract for photocatalytic decolourisation of Rhodamine B and antibacterial performance

In this study, copper oxide nanoparticles (CuO NPs) were synthesized through a green route using Ixora chinensis leaf extract as a natural reducing and stabilizing agent. The successful formation of Ixora -CuO NPs was indicated by a color change from blue to green upon addition of 1% (w/v) CuSO 4 solution, and further confirmed by a distinct UV-Vis absorption peak at 304 nm. SEM and TEM analyses revealed predominantly spherical, monodispersed NPs with sizes ranging from 15 to 25 nm, and XRD patterns confirmed a monoclinic CuO phase with an average crystallite size of 16.3 nm. Elemental analysis through EDX and XPS validated the purity and oxidation state (Cu 2+ ) of the nanoparticles. Thermal gravimetric analysis (TGA) indicated strong thermal stability, and BET surface area analysis demonstrated mesoporous characteristics with a surface area of 26.48 m 2 /g. The plant-mediate synthesized CuO NPs exhibited excellent photocatalytic activity, achieving up to 100% degradation of Rhodamine B dye under optimized conditions with pH-10, 0.1 g catalyst loading and 5 ppm dye initial concentration, with only 20% reduction in efficiency after seven reuse cycles. Moreover, antibacterial studies confirmed potent, dose dependent inhibition against both S.aureus and E.coli , surpassing the efficacy of conventional antibiotics at higher NPs concentrations. • CuO NPs were synthesized using Ixora chinensis leaf extract. • Monoclinic CuO phase with size of 16.3 nm, BET surface area is 26.48 m²/g. • 100% degradation of Rhodamine B dye with optimized conditions pH-10, 0.1 g catalyst loading and 5 ppm dye initial concentration. • Dose dependent inhibition against both S.aureus and E.coli .