Synthesis, Characterisation, and Investigation of Catalytic and Antimicrobial Activities of Zinc Oxide/Palladium-Silver Nanocomposites

This study aimed to create and characterise Zinc Oxide/Palladium-Silver (ZnO/Pd–Ag) nanocomposites (NCs) to enhance their antifungal, antibacterial, and catalytic properties. ZnO nanoparticles (NPs) were synthesised using a precipitation method, followed by the photo-deposition of silver and palladium onto the ZnO NPs. The nanocomposites’ structural, morphological, and chemical characteristics were analysed using XRD, SEM, EDX, FT-IR, and UV–Vis spectroscopy. Their antifungal and antibacterial properties were evaluated against specific pathogens, while blood compatibility was assessed through haemolytic activity. Additionally, the catalytic performance of the nanocomposites was tested by decolorising different dyes. The ZnO/Pd–Ag NCs demonstrated consistent antifungal activity against Aspergillus niger and Aspergillus flavus, with inhibition observed throughout 3 to 6 days. The nanocomposites also exhibited significant antibacterial effects against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. However, increased haemolytic activity was observed at higher concentrations, suggesting potential issues with blood compatibility. The nanocomposites showed significant changes at higher concentrations regarding catalytic activity, indicating their effectiveness in dye decolourisation. Overall, the study highlights the promising antimicrobial properties and catalytic potential of ZnO/Pd–Ag nanocomposites. Still, it also emphasises the need to address their biocompatibility, particularly concerning blood compatibility, for future applications as antimicrobial agents.