Nile blue (NB) dye is a highly toxic substance that when
discharged
into sewage presents a significant risk to the environment and human
health. Carbon-based nanomaterials, such as graphene oxide (GO), reduced
graphene oxide (rGO), and their nanocomposites, offer considerable
potential for eliminating hazardous pollutants from aqueous systems.
In this study, we have successfully fabricated bare GO and rGO, and
then, the rGO was decorated with silver (Ag) nanoparticles to develop
the Ag-rGO composite. The as-prepared materials were characterized
by various techniques, such as UV–visible (UV–vis) and
Fourier transform infrared (FTIR) spectroscopies, X-ray diffraction
(XRD), energy-dispersive X-ray (EDX), and scanning electron microscopy
(SEM) to elucidate their structure, morphology, and chemical composition.
The pollutant removal performance of the as-prepared materials was
evaluated through a batch approach under the effect of various experimental
variables for removal of NB dye from wastewater. As obvious, the Ag-rGO
composite revealed exceptional performance for NB dye removal from
wastewater, with a maximum removal percentage of 94% within 60 min,
which is remarkably higher than those of the rGO (i.e., 59%) and GO
(i.e., 22%), under the same experimental conditions. The adsorption
data was analyzed with thermodynamics, isotherms, and kinetics models
to better understand the physicochemical mechanisms driving the effective
removal of the NB dye. The results reveal that Ag-rGO nanocomposite
exhibit excellent adsorption ability as well as favorable thermodynamic
and kinetic parameters for NB dye removal. It was also found that
the presence of light enhanced the adsorptive removal of NB while
using Ag-rGO as an adsorbent. The present study noted significant
reusability of the Ag-rGO nanocomposite, likely due to minimal Ag
leaching and/or the robust stability of the Ag-rGO. It is suggested
that Ag-rGO-based hybrid materials could serve as promising candidates
for efficiently adsorbing and catalytically removing various toxic
pollutants from wastewater.