Green synthesis of binary nanostructured TiO2-ZrO2 composites using moringa oleifera gum: Photocatalytic and antimicrobial applications

In this study, we harnessed the eco-friendly properties of gum Moringa oleifera (GMO) to synthesize innovative TiO2 (ST1), ZrO2 (SZ1), and hybrid ZrO2-TiO2 (TZS1) nanoparticles through a green sol-gel method. Characterization techniques such as UV, FTIR, XRD, FE-SEM, EDS, HR-TEM, BET, and fluorescence spectroscopy unveiled unique features, including a reduced crystalline size and a low bandgap of 1.98 eV, with TZS1 achieving an impressive surface area of 39.099 m2/g. Our antimicrobial assessments demonstrated significant antibacterial activity against pathogens like Staphylococcus aureus and Escherichia coli, with TZS1 emerging as the most potent. Additionally, nanoparticles showcased remarkable photocatalytic degradation efficiencies of 96.34 % for methylene blue and 94.52 % for rhodamine B under solar light. Despite the well-documented photocatalytic and antibacterial capabilities of ST1 under UV light and the complementary characteristics of SZ1, critical research gaps remain. Additionally, although SZ1 has a higher band gap than ST1, its ability to modify ST1's band gap and extend its photocatalytic activity to a broader light spectrum, including visible light, remains inadequately explored. Addressing these gaps could unlock new avenues for optimizing these sustainable materials for diverse applications, paving the way for innovative antibacterial and photocatalytic solutions.