Silver nanoparticles assisted structuring of low-dimensional Ag–ZnO nano composites for enhancing photo catalytic properties under solar light

Abstract

Metal oxides functionalized with plasmonic nanoparticles have attracted significant attention for their enhanced photocatalytic activity and extensive applications in wastewater treatment. In this study, silver nanoparticle (Ag NP)-decorated zinc oxide (ZnO) nanocomposites (Ag–ZnO NCs) were synthesized through a simple and cost-effective chemical route where there was in situ formation of Ag nanoparticles (∼5 nm) and attachment during the growth of low-dimensional ZnO nanorods (length ∼25 nm, diameter ∼5 nm). The structural and optical properties of the Ag–ZnO NCs were thoroughly characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Visible absorption, photoluminescence (PL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). It was observed that the defect states of ZnO were significantly neutralized (∼90%) by carriers generated in Ag nanoparticles through the surface plasmon resonance (SPR) effect. The quenching of these defect states led to an increase in the photocatalytic activity of the Ag–ZnO composites. The photocatalytic performance of bare ZnO nanorods and Ag–ZnO NCs was evaluated by degrading methylene blue (MB), a model pollutant, under normal solar light (Power: 850 W/cm 2 ). Ag–ZnO NCs with higher concentrations of Ag NPs demonstrated exceptional degradation efficiency (∼98.5%) compared to conventional photocatalytic materials. • This study investigated solar-driven photocatalysis of Ag–ZnO NCs. • Low-dimensional Ag–ZnO NCs (∼10–25 nm in length) were fabricated. • Energy band gaps of Ag–ZnO NCs increased (3.32–3.37 eV) with more Ag attachment. • Nearly 90 % defect states in ZnO have been neutralized with Ag nanoparticle attachment. • Ag–ZnO NCs degraded ∼99 % of MB dye under sunlight in 90 min.

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