Photocatalytic Removal of Dye Pollutants from Water Using Co₃O₄ Nanoparticles Synthesized from Diplocyclos Palmatus Leaf Extract

Cobalt oxide nanoparticles (Co₃O₄-NPs) were synthesised via a green route using Diplocyclos palmatus leaf extract and evaluated for photocatalytic dye degradation. Structural analysis by XRD confirmed the cubic phase of Co₃O₄ with an average crystallite size of ۲۳ nm. SEM and EDX revealed irregularly spherical nanoparticles composed of cobalt and oxygen. The photocatalytic activity of Co₃O₄-NPs was assessed against methylene blue (MB) dye under sunlight irradiation. Key operational factors such as dye concentration, pH, catalyst dosage, and reusability were systematically investigated. The nanoparticles demonstrated excellent photocatalytic activity, achieving ۸۹% degradation of MB within ۱۲۰ minutes. Prolonged irradiation enhanced the degradation efficiency, with ۹۱% removal observed at pH ۹ for the same duration, confirming that alkaline conditions favour the process. Conversely, higher dye concentrations resulted in reduced degradation efficiency. At an optimised dosage of ۰.۰۱۳ g of catalyst, ۹۰% degradation was achieved, highlighting the role of catalyst loading in the process. Upon recycling, the catalyst retained substantial activity, degrading ۸۵% of the dye in the first cycle. Overall, the Co₃O₄ nanoparticles displayed reliable and visible-light-driven photocatalytic activity, underscoring their potential as promising materials for the removal of organic pollutants in wastewater treatment applications.

کلیدواژه ها:

Photocatalytic degradation ، Cobalt oxide nanoparticles (Co₃O₄-NPs) ، Diplocyclos palmatus ، Visible-light photocatalyst ، Methylene blue degradation