Tecoma stans intermediated green synthesis of copper oxide nanoparticles, their characterization, paracetamol degradation and biological activities

[Display omitted] •The synthesis of copper oxide nanoparticles have been accomplished using Tecoma stans leaves extract.•The green synthesized copper oxide nanoparticles participated in an effective photocatalytic degradation of paracetamol with an efficiency of about 95.15 %.•Copper oxide nanoparticles contributed its involvement in biological activities and showed a better performance towards antibacterial and acticancer activities. The main objective of the present research work is to green synthesize copper oxide nanoparticles (CuO NPs) and to study their potential against various enmities to safeguard our environment and health. Based on this approach, preparation of CuO NPs was accomplished using four different volumes (10, 25, 40, and 50 mL) of Tecoma stans leaves extract. Moreover, all the synthesized CuO NPs were characterized using XRD, UV–visible, FTIR, and SEM with EDS analysis. From the XRD pattern, the structures of all the synthesized CuO NPs were found to be monoclinic in phase. According to the UV–visible studies, the calculated band gap energy values for all the prepared CuO NPs were higher compared to bulk CuO, which was 1.2 eV. Further, the FTIR results showed thez presence of CuO bonds, and SEM with EDS analysis revealed the surface morphology of CuO NPs and the presence of elements, showing the purity of synthesized CuO NPs, respectively. The optimized condition for the preparation of CuO NPs was 50 mL of leaves extract mixed with 50 mL of double-distilled water (CuO4 NPs), which showed a spheroidal morphology as evident from the HRTEM images. XPS analysis was used to find the oxidation state of detected elements, especially for copper and oxygen. The predicted BET and Langmuir surface areas of CuO4 NPs were calculated to be 40.305 m2/g and 5074.12 m2/g, respectively. Photocatalytic degradation of paracetamol (PCM) using CuO4 NPs was investigated, and the effect of parameters such as pH, initial concentration of PCM solution, and catalyst dosage were studied under UV light irradiation. The highest removal of 95.15 % had been achieved at 120 min under optimized reaction conditions. Additionally, CuO4 NPs also exhibited exemplary antibacterial activity against bacillus subtilis bacteria with a zone of inhibition of 26 mm. Further, in vitro cytotoxic behaviour of CuO4 NPs was estimated using A549 cancer cells by MTT assay. Thus, the green synthesized CuO NPs using Tecoma stans leaves extract has the capacity to participate in photocataly