Green synthesis of nano Cu2O for one-pot photocatalytic production of vitamin B3

One of the main goals of nanotechnology is the development of visible-light-active, sustainable, and non-toxic nanostructured photocatalysts; this emphasizes the necessity of eco-friendly synthesis techniques. This study presents a simple and low-temperature biosynthesis route for producing Cu₂O nanoparticles (NPs) from leaf extract and mangrove species (Avicennia marina). The biosynthesized Cu₂O nanocatalyst, optimized at an extract content of 0.5 g·100 mL⁻¹, displayed a band gap energy of 2.1 eV and an average particle size of approximately 40 nm. In this process, 3-pyridinemethanol was photocatalytically oxidized using the Cu₂O nanocatalyst to produce vitamin B₃ (nicotinic acid), achieving an impressive 99% yield. Under visible light irradiation, Cu₂O generates electron–hole pairs that drive redox reactions. The presence of alcohol-based hole scavengers minimizes charge carrier recombination, thereby enhancing photocatalytic efficiency. This approach offers a green, energy-efficient alternative for vitamin synthesis, aligning with the principles of sustainable chemistry. The results demonstrate the potential of biologically derived nanomaterials for eco-friendly organic synthesis and open avenues for future research into sustainable production of value-added compounds.