Abstract:
Highly dispersed Cobalt doped ZnS nanostructures were successfully fabricated on the surfaces of
graphene sheets via a simple hydrothermal method. X-ray diffraction (XRD), X-ray photocurrent
spectroscopy (XPS), Raman spectroscopy (RS), Fourier transform infrared spectroscopy (FTIR) and
Scanning electron microscopy (SEM) were utilized to analyze the structural characteristics of the
cobalt doped ZnS decorated with graphene CoxZn1−xS rGO nanostructures (NSs). UV-visible optical
absorption (UV-vis) studies were conducted to investigate their optical properties. In laboratory studies
utilizing water and visible light, the photocatalytic activity of CoxZn1−x SrGO NSs at (x = 0, 1, 2, 4 and
6 atm.%) were evaluated. Graphite Oxide (GO) was successfully transformed into sheets of graphene
and CoxZn1−xS rGO NSs possessed a crystalline structure according to the findings of XRD, RS and
FTIR analysis. SEM investigation showed graphene sheets enhanced with ZnS NSs possessed cuboidal,
spheroidal form of structure and displayed a paper like appearance. UV-vis confirmed a noticeable rapid
increase in transmittance along the UV wavelength area and confirmed a highly transparent NSs in the
wavelength range of (180-800 nm). Calculations using density functional theory (DFT) revealed that
the Co NSs have more negative conduction bands than ZnS, allowing for effective electron transfer
from cobalt to ZnS and exhibiting a band gap decrease as Co content increased. The Co0.04Zn0.96S rGO
NSs sample had the highest photocatalytic activity, measured at 7648.9 μmol h−1. A combination of
improved dispersion properties, greater surface area, increased absorption and enhanced transfer of
photogenerated electrons, CoxZn1−x S rGO NSs increased the photocatalytic hydrogen generation
activity.
