Enhancement of Methylene Blue Photodegradation Rate Using Laser Synthesized Ag-Doped ZnO Nanoparticles

Abstract

In this work, Ag-doped ZnO nanoparticles are obtained via pulsed laser ablation of the Ag-coated ZnO target in water. The ratio of Ag dopant in ZnO nanoparticles strongly depends on the thickness of the Ag layer at the ZnO target. Synthesized nanoparticles were characterized by XRD, XPS, SEM, EDS, ICP-OES, and UV–VIS spectrophotometry to obtain their crystal structure, elemental composition, morphology and size distribution, mass concentration, and optical properties, respectively. The photocatalytic studies showed photodegradation of methylene blue (MB) under UV irradiation. Different ratios of Ag dopant in ZnO nanoparticles influence the photodegradation rate. The ZnO nanoparticles doped with 0.32% silver show the most efficient photodegradation rate, with the chemical reaction constant of 0.0233 min−1. It exhibits an almost twice as large photodegradation rate compared to pure ZnO nanoparticles, showing the doping effect on the photocatalytic activity.

Ag-Loaded ZnO Nanocomposite Films as Photocatalysts for the Degradation of Pigments under Visible Light

“…Fitting the Ag 3d fine spectrum shows two peaks centered at 367.5 and 373.5 eV corresponding to Ag 3d 5/2 and Ag 3d 3/2 , respectively. Compared to the pure Ag films (Ag 3d 5/2 , 368.2 eV and Ag 3d 3/2 , 374.2 eV), the shift in binding energy is associated with the electron transfer between Ag particles and ZnO films . The O 1s fine spectrum in Figure d is well reproduced by two Lorentzian–Gaussian peaks situated at 530.42 and 531.89 eV, which is correlated with oxygen in the ZnO crystal lattice and surface-chemical-absorbed O 2 , respectively …”

“…The Zn 2p 3/2 and 2p 1/2 peaks are situated at approximately 1021.5 and 1044.7 eV, respectively, and the standard energy difference of 23 eV indicates that the Zn element exists in the form of Zn 2+ , which also confirms the existence of ZnO. 22 Figure 4c shows the binding energy of the Ag 3d peak. Fitting the Ag 3d fine spectrum shows two peaks centered at 367.5 and 373.5 eV corresponding to Ag 3d 5/2 and Ag 3d 3/2 , respectively.…”

Photoluminescence and enhanced photocatalytic activity of mechanically activated graphite-zinc oxide composites

“…Generally, in UV-vis spectroscopy, this can result in a decrease in absorbance at the wavelength of interest. However, in some cases [22][23][24][25], photobleaching can also cause an increase in absorbance, because of the formation of a new product from the photobleaching of MB or a shift in the absorbance spectrum, resulting in a higher absorbance at 664 nm. It would be interesting to investigate this further in a subsequent investigation.…”

Photocatalytic activity of hybrid Ag/Er:ZnO nanoparticles synthesized by pulsed laser ablation in distilled water

“…Moreover, many reported studies have shown that ZnO modified with appropriate dopants (such as rare-Earth (RE) elements and noble metals) can exhibit improved properties compared to the pristine ZnO in different applications [8][9][10][11][12][13][14][15]. For example, the photocatalytic properties of ZnO nanoparticles have been enhanced upon doping with europium ions (Eu 3+ ) [16][17][18], erbium ions (Er 3+ ) [19][20][21][22][23][24][25], and by hybridization with selected noble metal such as silver (Ag) [26][27][28][29][30][31][32][33][34][35][36][37][38][39]. The observed effective separation of the photo-generated charges in ZnO has been attributed to the electron-scavenger effect of the noble metal [26] and the point defects introduced by RE-doping [23].…”

“…Also, ZnO NPs with antibacterial activity [53], and Zn@ZnO core-shell nanostructures for sensing hydroquinone [54] have been synthesized by PLAL. In addition, Ag/ZnO nanoparticles with enhanced photocatalytic activity [36,55] and anticancer nature [56], have been produced by PLAL using Zn and Ag metallic targets [55,56] and Ag-coated ZnO target [36] in water. Furthermore, Ag/Au-ZnO plasmonic hybrid nanomaterials have been synthesized by pulsed laser ablation of Ag/Au bimetallic in water followed by mixing with ZnO nano-powder and by laser irradiation of the mixture [57].…”