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 plasmonicAg nanostructures (NSs) on ZnO fabricated by RF magnetron sputtering technique. The Ag NSswas grown on ZnO coated surface by functionalizing the thin film with mussel-inspiredpolydopamine. The structural analysis was performed by Grazing Incident X-ray diffraction(GIXRD) and Fouirer Transform Infrared Spectrometer (FTIR) technique in order to observe theeffect of the Ag NSs deposition times. The effect of growth conditions on the structure and sizeof Ag NSs was investigated by Field Emission Scanning Electron Microscope (FESEM) imagingtechnique. The chemical compositions of as-deposited and Ag decorated ZnO films confirmsusing Energy-dispersive X-ray spectroscopy (EDX) analysis. The catalytic performance of themulti-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 isfound that maximum catalytic performance was observed within first 15 min for the ZnO thinfilms that were decorated with Ag NSs for 24h. The rate constant for the degradation reactionwas 33.8x10-3 min-1 and 43.2x10-3 min-1 for MO and RhB, respectively. These results show thepromise of integrating metal oxide films with plasmonic structures for efficient degradation oforganic dyes.