The high demand for nanomaterials in the field of industry and science has forced researchers to develop new synthesis methods that are more efficient, economical, and environmentally friendly. At present, the application of green synthesis has taken a great advantage over conventional synthesis methods because it helps with the control of the characteristics and properties of the resulting nanomaterials. In this research, ZnO nanoparticles (NPs) were synthesized by biosynthesis using dried boldo (Peumus boldus) leaves. The resulting biosynthesized NPs had a high purity, quasi-spherical shape with average sizes ranging from 15 to 30 nm and a band gap of ~2.8–3.1 eV. These NPs were used in the photocatalytic activity of three organic dyes. The results showed degradation of 100% methylene blue (MB) in 180 min, 92% methyl orange (MO) in 180 min, and 100% Rhodamine B (RhB) in 30 min of exposure. These results show that the Peumus boldus leaf extract is effective in the biosynthesis of ZnO NPs with good photocatalytic properties.

Aguama (Bromelia pinguin L.), a plant belonging to the Bromeliaceae family, possesses a rich content of organic compounds historically employed in traditional medicine. This research focuses on the sustainable synthesis of ZnO nanoparticles via an eco-friendly route using 1, 2, and 4% of Aguama peel extract. This method contributes to environmental sustainability by reducing the use of hazardous chemicals in nanoparticle production. The optical properties, including the band gap, were determined using the TAUC model through Ultraviolet–Visible Spectroscopy (UV–Vis). The photocatalytic activity was evaluated using three widely studied organic dyes (methylene blue, methyl orange, and rhodamine B) under both solar and UV radiation. The results demonstrated that the ZnO nanoparticles, characterized by a wurtzite-type crystalline structure and particle sizes ranging from 68 to 76 nm, exhibited high thermal stability and band gap values between 2.60 and 2.91 eV. These nanoparticles successfully degraded the dyes completely, with methylene blue degrading in 40 min, methyl orange in 70 min, and rhodamine B in 90 min. This study underscores the potential of Bromelia pinguin L. extract in advancing sustainable nanoparticle synthesis and its application in environmental remediation through efficient photocatalysis.