Eco-friendly fabrication of CuO nanorods using Allium bourgeaui subsp. bourgeaui extract and their performance in methylene blue degradation, dopamine detection, and optoelectronics

Green synthesis provides a sustainable route for functional nanomaterials, yet linking their electronic structure to multifunctional performance remains challenging. In this work, CuO nanorods were synthesized using Allium bourgeaui subsp. bourgeaui extract as a reducing and stabilizing agent. XRD, FT-IR, UV–Vis, SEM, and EDS analyses confirmed monoclinic CuO nanorods (194.93 nm) with a band gap of 1.84 eV. The nanorods achieved 51.33% methylene blue (MB) degradation under UV light, demonstrating photocatalytic activity. A CuO/TCNQ composite enabled dopamine detection with a 0.214 µM detection limit. As an interlayer in an Al/CuO/n-Si photodiode, the device operated in self-powered mode, exhibiting 7.13 mA/W responsivity, 3.06 photosensitivity, and 1.49 × 109 Jones detectivity under solar illumination. These results highlight green-synthesized CuO as a versatile material for photocatalytic, sensing, and optoelectronic applications.