Eur. Phys. J. Plus (2022) 137: 60
https://doi.org/10.1140/epjp/s13360-021-02252-8

Regular Article

Effect of precursor material, pH, and aging on ZnO nanoparticles synthesized by one-step sol–gel method for photodynamic and photocatalytic applications

Faculty of Physics, Semnan University, PO Box, 35195-363, Semnan, Iran

^b m_aliannezhadi@semnan.ac.ir

Received: 6 May 2021
Accepted: 2 December 2021
Published online: 25 December 2021

Abstract

Zinc oxide nanostructures have extensive industrial and biomedical applications. In this paper, ZnO nanoparticles are synthesized by facile and low-cost sol–gel method. The effect of synthesis parameters including precursor material (zinc nitrate and zinc acetate), solution pH, and aging time is investigated on the structural, morphological, and optical properties of ZnO nanoparticles. The results reveal that using zinc acetate leads to an extensively uniform distribution of nanoparticles. Also, the dimensions of ZnO rod-like nanoparticles are significantly affected by precursor material and pH of the solution, in such a way that the aspect ratio of nanorods increased/decreased with increasing pH for the samples synthesized from zinc acetate/zinc nitrate. The structural characterization shows that all the samples are formed in the hexagonal phase. So, the precursor material, solution pH, and even aging time do not significantly influence the crystalline phase of ZnO nanoparticles. However, they significantly affect the crystallite size. The characteristic vibration modes of hexagonal ZnO are observed in the Raman and FTIR spectra of all the samples. A broad absorption band in the range of 220–420 nm is detected in the diffuse reflectance (DRS) spectra of all the samples. The bandgap of the samples is not significantly affected by the synthesis parameters. Moreover, the best synthesis condition for obtaining a sample with high absorption and low backscattering in the absorption band is determined by comparing UV–Vis–NIR and DRS results. The aging of samples synthesized using zinc acetate at pH of 13 declares that aging time can control the morphology without crystalline phase transition.