Polydopamine Mediated Growth of Ag Nanostructures on ZnO Thin Films for Catalytic Degradation of Organic Dyes

Abstract

In this study, multi-functional films were produced by the solution-phase growth of plasmonic Ag nanostructures (NSs) on ZnO fabricated by RF magnetron sputtering technique. The Ag NSs was grown on ZnO coated surface by functionalizing the thin film with mussel-inspired polydopamine. The structural analysis was performed by Grazing Incident X-ray diffraction (GIXRD) and Fouirer Transform Infrared Spectrometer (FTIR) technique in order to observe the effect of the Ag NSs deposition times. The effect of growth conditions on the structure and size of Ag NSs was investigated by Field Emission Scanning Electron Microscope (FESEM) imaging technique. The chemical compositions of as-deposited and Ag decorated ZnO films confirms using Energy-dispersive X-ray spectroscopy (EDX) analysis. The catalytic performance of the multi-functional films was investigated by the degradation of organic dyes (methyl orange (MO) and rhodamine B (RhB)).The catalytic activity of Ag on the is examined in details where it is found that maximum catalytic performance was observed within first 15 min for the ZnO thin films that were decorated with Ag NSs for 24h. The rate constant for the degradation reaction was 33.8x10-3 min-1 and 43.2x10-3 min-1 for MO and RhB, respectively. These results show the promise of integrating metal oxide films with plasmonic structures for efficient degradation of organic dyes.