Synthesis and structural properties of Mn-doped ZnO/Graphene nanocomposite

Zinc oxide (ZnO) is a promising metal oxide semiconductor with various applications, especially in the photocatalytic destruction of environmental pollutants. However, this nanoparticle has some limitations, such as poor dispersion, aggregation, and a wide energy gap. As such, the doping of metal oxide semiconductor has been strongly recommended. Addition of manganese (Mn) has proven effective in resolving these issues. On the other hand, addition of carbon-based materials (e.g., graphene) could improve the stability and photocatalytic efficiency of ZnO. Graphene oxide acts as an electron- transport and electron-acceptor agent, controlling the charge transfer in the ZnO/graphene nanocomposite interface. The present study aimed to synthesize manganese-doped graphene/ZnO nanocomposites and determine its structural properties. Some techniques were employed to characterize the prepared composites, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), dynamic light scattering (DLS), and zeta potential analysis. According to the FTIR analysis, the peak in the range of 3467 cm-1 was due to the presence of zinc groups in the graphene structure, and the peak observed at 439 cm-1 also indicated the presence of Mn in the compound. Furthermore, the results of AFM analysis showed that graphene to be a layered sheet with the mean thickness of 1.48 nanometers. The results of the DLS analysis showed the mean diameter of GO-ZnO-Mn to be 37 nanometers, which reduced after graphene modification. According to the findings, addition of Mn and ZnO to graphene could effectively result in doping.