Photocatalytic degradation of rhodamine B using Cu₂O prepared via Terminalia catappa leaf-extract route
DOI:
https://doi.org/10.54939/1859-1043.j.mst.110.2026.92-99Keywords:
Green synthesis; Cu₂O photocatalyst; Terminalia catappa leaf extract; Rhodamine B; photodegradation.Abstract
A green and sustainable method for synthesizing a cuprous oxide (Cu₂O) photocatalyst was established using the extract from Terminalia catappa leaves as a natural reducing and stabilizing agent. The resulting Cu₂O displayed a well-defined cubic morphology, high crystallinity, and phase purity, as confirmed by SEM, XRD, FTIR, and EDX analyses. UV-Vis diffuse reflectance spectroscopy indicated strong visible-light absorption, with characteristic bands at 449 and 475 nm and a narrow band gap of 2.12 eV, supporting its suitability for visible-light-driven photocatalysis. Photocatalytic activity was assessed via degradation of Rhodamine B (RhB) under visible-light irradiation, achieving over 90% degradation within 120 minutes. Kinetic analysis showed that the photodegradation data were best fitted by a pseudo-second-order model, reflecting an apparent kinetic behavior in which surface reactions and adsorption-related processes involving photogenerated charge carriers play a dominant role. Reusability tests demonstrated satisfactory stability, with the catalyst maintaining more than 80% degradation efficiency after five cycles. These findings demonstrate the potential of Terminalia catappa leaf-extract-mediated Cu₂O as an eco-friendly, low-cost, and efficient photocatalyst for wastewater treatment.
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