Green synthesis of CuO and Mn-doped CuO nanoparticles using Ipomoea staphylina leaf extract for photocatalytic degradation, antioxidant, and antibacterial activities

The present investigation was aimed to synthesize the copper oxide (CuO NPs) and manganese-doped CuO (Mn-doped CuO NPs) nanoparticles through green synthesis using Ipomoea staphylina leaf extract, and their antioxidant, antibacterial, and photocatalytic properties were evaluated. The optical band gap energy was calculated using the Kubelka–Munk function, which is 3.97 eV for CuO and 3.77 eV for Mn-doped CuO NPs. Powder X-ray diffraction revealed an average crystallite size of 27.12 nm for undoped CuO and 18.37 nm for Mn-doped CuO, FE-SEM images revealed the formation of CuO (irregular spherical) and Mn-CuO (aggregative sheet and rod-like), and XPS validated the synthesized materials’ purity and crystalline nature. FT-IR spectroscopy indicated the existence of phytochemical coatings on the surface of the synthesized materials. The highest antibacterial activity was observed against the Staphylococcus aureus, with the zone of inhibition (ZOI) measuring 20 mm and 23 mm for green-synthesized CuO and Mn-doped CuO NPs. The synthesized nanoparticles effectively scavenged DPPH radicals with antioxidant activity of 58 and 69% for CuO and Mn-CuO NPs. Furthermore, photocatalytic activity is 94% for the photocatalytic degradation of Congo red (CR) dye. Our findings revealed that the green synthesized nanoparticles encompass outstanding biological potential with photocatalytic activity, making them suitable for various biomedical and environmental applications.