Green Synthesized ZnO/rGO/P. guajava Nanocomposite for Photocatalytic Dye Degradation and Antifungal Studies
J. Environ. Nanotechnol., Volume 15, No 2 (June 2026) pp. 767-779
Abstract
Industrial discharge of dye-containing wastewater and microbial contamination pose environmental and health concerns, necessitating the development of stable and eco-friendly multifunctional materials. ZnO shows photocatalytic and antimicrobial activity, but its application is limited by rapid electron–hole recombination and reduced stability. To address these limitations, a ZnO/rGO/Psidium guajava nanocomposite was prepared using P.guajava leaf extract through a sol–gel method. Psidium guajava leaf extract was employed as a green reducing and stabilizing agent for ZnO/rGO nanocomposite synthesis, yielding a multifunctional material with photocatalytic and antifungal properties. Phytochemicals served as reducing and stabilizing agents during synthesis. The nanocomposite was characterized using XRD, FTIR, SEM, and UV–DRS, and photocatalytic activity was assessed for MG degradation under UV-A irradiation by varying pH, catalyst dosage, dye concentration, and reusability. The nanocomposite achieved ~100% MG degradation within 90 min at pH 7, 75 mg catalyst, and 2×10 M under UV-A irradiation. The nanocomposite showed a band gap of 2.9 eV, optimum catalyst dosage of 75 mg, and retained 85% degradation efficiency after five cycles. Scavenger studies indicated superoxide radicals as the primary reactive species. The nanocomposite exhibited limited antifungal activity consistent with reported ZnO/rGO composites, suggesting potential applicability for laboratory-scale wastewater treatment and antimicrobial studies.
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Reference
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