The functional kaolin-supported bimetallic Fe/Ni nanoparticles (K-Fe/Ni) were synthesized and applied in
remediation of Direct Black G (DBG), where batch study showed that 99.97% of DBG was removed from
aqueous solution using K-Fe/Ni, whereas only 95.89% and 13.34% were removed using Fe/Ni and kaolin,
respectively. Kaolin-supported Fe/Ni led to decrease in aggregation of Fe/Ni nanoparticles, increase in
adsorption of DBG onto the kaolin and enhanced reduction of DBG by Fe/Ni on K-Fe/Ni to form iron oxide,
the functional K-Fe/Ni nanoparticles based on adsorption and reduction was confirmed by characterization
using scanning electron microscopy (SEM) and X-ray diffraction (XRD). UV–Vis spectra showed that
the DBG was degraded by the break in azo linkages, and Fourier infrared spectra (FTIR) shows that new
bands appeared which corresponded to AN@NA after K-Fe/Ni reacted with DBG. Furthermore, kinetics
studies showed that the degradation of DBG fitted well with the pseudo first-order model and the degradation
pathways of DBG using K-Fe/Ni was proposed. Finally, K-Fe/Ni used for the degradation of DBG
in wastewater was demonstrated as a potential technique for the remediation.