Green synthesis of ZnO-doped cerium oxide nanocomposite using clove extract: enhanced photocatalytic methylene blue degradation and antibacterial properties

In this study, we present a green synthesis method for producing ZnO-doped CeO₂ nanocomposites (ZnO–CeO₂ NC) and CeO₂ nanoparticles (NPs) using clove (Syzygium aromaticum) extract. Our main objective is to assess their properties, focusing on their photocatalytic and antibacterial activities. Through comprehensive characterization techniques such as powder XRD, UV–vis DRS, and FTIR analyses, we thoroughly evaluated the synthesized materials. Notably, both the green-synthesized CeO₂ (CLV30) NPs and ZnO–CeO₂ (CZn) NCs demonstrated exceptional efficiency, degrading methylene blue dye by 89% and 94%, respectively, under visible light irradiation. The CZn nanocomposites exhibited remarkable reusability and stability over four cycles. Additionally, significant antibacterial activity was observed, with CLV30 exhibiting moderate effectiveness against Gram-negative Escherichia coli (E. coli) (8 mm) and Gram-positive Staphylococcus aureus (S. aureus) (11 mm) compared to CZn, which displayed notable inhibitory zones of 24 mm and 35 mm against E. coli and S. aureus, respectively. These findings highlight the versatile applications of these nanomaterials across various fields.