Synthesis and characterization of Sr-doped ZnO nanoparticles for photocatalytic applications

The use of semiconductors that respond to the visible light as a photocatalyst is an effective way to remove pollution resulting from the chemical industries. In this project, with the aim of increasing its photocatalytic activity, zinc oxide (ZnO) was doped with 1, 3, 5 and 7 M% strontium (Sr) by mechanical milling method. Characterization of the synthesized powders was done by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). The optical behavior was evaluated using UV-Vis diffuse reflectance spectra (UV-Visible DRS) and photoluminescence. The XRD results showed successful doping of Sr in ZnO. The results of microscopic characterization revealed that the size of Sr-doped particles was in the range of 20-60 nm. Just about all results showed that the 3% Sr-doped ZnO sample (ZnO-Sr3) revealed the best performance. Its band gap decreased from 3.34 to 3.17 eV. Investigated by radiation of the HMI lamp for degradation of methylene blue (MB) dye, the photocatalytic efficiency of ZnO-Sr3 sample increased from 56 to 97%. Also, the results of chronoamperometry test showed a 3-fold increase in the photocurrent of ZnO-Sr3. Antibacterial studies of the samples on Escherichia coli (E. coli) bacterium also revealed that the ZnO-Sr3 sample had the highest antibacterial property. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Doping zinc oxide with strontium improved its photocatalytic activity, with the best performance observed at 3% strontium doping. The band gap of the photocatalyst decreased from 3.34 to 3.17 eV, leading to a significant increase in the degradation of methylene blue dye.