Affiliation:
1. UNESCO‐UNISA Africa Chair in Nanosciences/Nanotechnology Laboratories, School of Interdisciplinary Research and Graduate Studies, College of Graduate Studies University of South Africa (UNISA) Roodepoort Johannesburg South Africa
Abstract
AbstractAs a result of their unique and novel properties, nanocomposites have found applications in a wide variety of fields. The purpose of this study is to demonstrate the ability to synthesize nanoparticles consisting of zinc oxide (ZnO) and graphene oxide (GO) via sol–gel techniques. An x‐ray diffractometer (XRD) as well as a UV–visible spectrometer were used to determine the crystalline and optical characteristics of the prepared samples. A hexagonal wurtzite crystal structure was observed in both pure ZnO nanoparticles and those that contain GO based on XRD results. It was estimated that the average crystallite size is based on the broadening of x‐ray lines. In comparison with pure ZnO, the antimicrobial properties were enhanced when GO was incorporated with ZnO. In addition, experiments on the absorption edge indicated the presence of a red shift as a result of the incorporation of GO. When GO is incorporated in quantitative amounts, the bandgap value of pure ZnO decreased. FTIR spectra exhibit a band of absorption at 486 cm−1, which confirms Zn‐O stretching in both samples. SEM images reveal a random pattern of structural features on the surface of the prepared samples. According to the EDX spectrum, pure GO nanoparticles and those doped with ZnO contain 61%–64% zinc and 32%–34% oxygen, respectively. When annealed at a higher temperature, ZnO NPs produced more H2 with a narrower bandgap than before annealing. In addition, methyl blue (MB) was used as an example of an organic compound in order to investigate the potential photocatalytic properties of nanoparticles with ZnO doped GO. In addition to DPPH assays, ZnO nanoparticles and ZnO doped GO nanoparticles were tested for their ability to scavenge free radicals. Comparing ZnO doped GO NPs with pure ZnO, these nanoparticles showed increased antioxidant activity. Based on the increased zone of inhibition observed for pure ZnO and ZnO doped GO (5, 10, 50, and 100 mg/mL), the antibacterial activity of pure ZnO and ZnO doped GO is concentration dependent. A detailed discussion of the results of the study demonstrated that ZnO doped GO and pure ZnO are toxic in different ways depending on how long they survive in degreased Zebrafish embryos and how fast they decompose.Research Highlights
The scope of the manuscript was under the results of the study confirmed that both nanoparticles exhibited concentration dependent antioxidative activity.
Determined that 89% of methyl orange dye can be degraded photocatalytically.
ZnO nanoparticles were found to be 74.86% antioxidant at a concentration of 50 g/mL in the present study.
At a concentration of 50 g/mL, ZnO doped GO NPs showed 79.1% antioxidant activity.
Photocatalytic degradation mechanism scheme is implicit in the photoexcited charge carrier transportation path is observed for all the samples.
Survival rate of zebrafish embryos was shown to decrease with increasing concentrations of ZnO and zinc oxide plus GO nanoparticles.
Funder
University of South Africa