Explorin g Heliotropium indicum Leaf Extract Assisted Green Synthesis of CuO Nanoparticles for Tetracycline Degradation and Antimicrobial Activity

Abstract Green‐synthesized copper oxide nanoparticles (both CuO NPs and Cu 2 O NPs) have drawn increasing attention due to their distinctive properties and diverse applications. This study aims to synthesize CuO NPs and Cu 2 O NPs using leaf extracts from the traditional medicinal plant Heliotropium indicum (H.I) and assessing their photocatalytic and antibacterial performance. X‐ray diffraction (XRD) analysis confirmed monoclinic CuO and cubic Cu 2 O structures with crystallite sizes of 20 nm and 17 nm, respectively. SEM and TEM analysis showed that the synthesized HI@Cu 2 O NPs exhibited a near‐spherical morphology with an average size of ∼10 nm, while HI@CuO NPs displayed a self‐assembled spherical‐like structure with an average size of ∼230 nm. The FTIR analysis reveals distinct functional groups in the nanoparticles, compared to the plant extract. The degradation efficiency of tetracycline (TC) reaches 82% and 78% within 60 min for HI@Cu 2 O NPs and HI@CuO NPs, respectively. Turnover number (TON) and turnover frequency (TOF) were determined for the visible light‐driven photocatalytic degradation of TC. Results showed that HI@Cu 2 O NPs exhibited superior antibacterial performance against Staphylococcus aureus compared to HI@CuO NPs. Thus, a facile sustainable synthesis of CuO NPs using H. indicum leaf extract highlights their potential for application in photocatalytic wastewater treatment and biomedical fields.