The effect of silver oxidation on the photocatalytic activity of Ag/ZnO hybrid plasmonic/metal-oxide nanostructures under visible light and in the dark

Abstract

A new synergetic hybrid Ag/ZnO nanostructure was fabricated which is able to cause photocatalytic degradation (in high yields) of methylene blue under visible light as well as in the dark. In this nanostructure, ZnO was synthesized using the arc discharge method in water and was coupled with Ag via a chemical reduction method. X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy results confirmed the existence of defects in ZnO in the hybrid nanostructures; these defects act as electron traps and inhibit the recombination of electron-hole pairs. The absorption edge of the hybrid nanostructure shifts toward the visible region of the spectrum due to a combination of the Ag plasmonic effect and the defects in ZnO. Band-edge tuning causes effective visible light absorption and enhances the dye degradation efficiency of Ag/ZnO nanostructures. Silver oxidation in the hetero-structure changed the metal-semiconductor interface and suppressed the plasmonic enhancement. Nevertheless, the synthesized Ag/ZnO decomposed methylene blue in visible light, and the silver oxidation only affected the catalytic activity in the dark. This work provides insight into the design of a new and durable plasmonic-metal oxide nanocomposite with efficient dye degradation even without light illumination.

Silver decorated CeO2 nanoparticles for rapid photocatalytic degradation of textile rose bengal dye

“…Dawoud et al 24 observed that Ag doped ZrO 2 nanoparticles are effectively degraded the RB dye in visible light irradiation because of the surface area, band gap and porosity. Similar degradation effect has been observed by Ziashahbi et al 25 using Ag decorated ZnO hybrid nanostructures against methylene blue under visible light.…”

Recent Advances in Zinc Oxide Nanostructures with Antimicrobial Activities

“…Therefore, PtNPs induce a blue shift in the optical spectrum of Pt/ZnO nanocomposites [126]. In this respect, plasmonic AgNPs are commonly employed to enhance photocatalytic efficiency of ZnO under visible light [127,128]. As mentioned, a Schottky barrier is established at the metal/ZnO interface when noble metal comes in contact with ZnO.…”

MEMS-compatible, gold nanoisland anchored 1D aligned ZnO heterojunction nanofibers: unveiling the NO2 sensing mechanism with operando photoluminescence studies

“…Metal oxide semiconductor (MOS) based heterojunction nanostructures have been extensively used for a wide range of fascinating applications in the emerging fields of oxidation catalysis, 1 photocatalytic degradation, 2 CO oxidation, 3 photoelectrochemial water splitting, 4 toxic gas detection 5 etc. Among various heterojunction materials, MOSs with plasmon mediated interfacial catalytic properties due to surface anchored noble metal nanoclusters have shown excellent sensing properties, especially towards detection of oxidizing gases, like NO2.…”