Green biochar-supported ZnFe2O4 composite photocatalyst derived from waste banana peel: a sustainable approach for highly efficient visible Light-driven degradation of organic pollutants in wastewater

• Published in: Ionics 2024-09, Vol.30 (9), p.5639-5650
• Main Authors: Meena, R., Abdullah, Mahmood M. S., Vasanthakumar, V., Ravichandran, D., Murugesan, S.
• Format: Article
• Language: English
• Subjects: Catalysts; Catalytic activity; Charge efficiency; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Crystal structure; Electrochemistry; Energy Storage; Light irradiation; Methylene blue; Optical and Electronic Materials; Optical properties; Performance degradation; Photocatalysis; Photocatalysts; Photodegradation; Pollutants; Renewable and Green Energy; Solid phases; Structural analysis; Wastewater treatment; Zinc ferrites; Zinc oxide
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-024-05665-4

Ferrite-based photocatalysts have raised as potent agents for breaking down organic pollutants in wastewater treatment. However, the challenge of developing an environmentally sustainable and economically viable photocatalyst with heightened efficacy persists. In this study, we prepared a green biochar-supported ZnFe 2 O 4 (BC-ZnFe 2 O 4 ) composite catalyst through a simple calcination method using waste banana peel (Macho plantain) . The physicochemical properties of the prepared catalysts were thoroughly characterized, encompassing phase structure, surface morphology, purity, size, optical features, and charge separation efficiency. The characterization results confirmed that the ZnFe 2 O 4 had a specific crystal structure in the composite. Microscopic analysis showed that the BC-ZnFe 2 O 4 composite had a consistent cubic-like shape, with grains sized between 60–80 nm. Importantly, these BC-ZnFe 2 O 4 composite had a direct band gap of about 2.29 eV, making them suitable for photocatalytic reactions. The photocatalytic methylene blue (MB) degradation experiments revealed that BC-ZnFe 2 O 4 (91.08%; k = 0.3938 min −1 ) exhibits a superior photocatalytic activity compared to its pure BC-ZnO (75.26; k = 0.2129 min −1 ) counterparts within 100 min visible light irradiation. The excellent photocatalytic performance of the BC-ZnFe 2 O 4 composite was due to the combined effect of the biochar and ZnFe 2 O 4 , which generated reactive oxygen species during the degradation process. In addition, the as-prepared BC-ZnFe 2 O 4 composite demonstrated remarkable catalytic stability throughout multiple reaction cycles, making it suitable for sustained degradation of dye pollutants. Considering the outstanding performance of BC-ZnFe 2 O 4 composite for the photocatalytic reaction, we believe that BC-ZnFe 2 O 4 holds significant potential for purifying pollutants in various applications.