In this work, a superabsorbent polymer,
sodium polyacrylate, also
known as water ball (WB), loaded with Ni, Cu, and Ag zero-valent metal
nanoparticles (MNPs) was applied for environmental remediation. WBs
loaded with Ni, Cu, and Ag NPs were evaluated for their catalytic
performance against the reduction of 4-nitrophenol (4-NP) to 4-aminophenol
(4-AP) and decolorization of methyl orange (MO), Congo red (CR), and
methylene blue (MB) dyes. The apparent rate constants (K
app) for the reduction of 4-NP to 4-AP in the presence
of Ni, Cu, and Ag NPs were 2.1 × 10–1, 2.9
× 10–1, and 4.6 × 10–1 min–1, respectively, indicating the strongest
activity of WB loaded with Ag NPs as compared to the other two catalysts.
Similarly, WB loaded with Ag NPs showed the highest K
app values compared to the other two catalysts. Among
all of the bacteria studied, except Providencia stuartii and Streptococcus mutans, the zone
of inhibition of Ag was higher as compared to that of the Ni and Cu
NPs, however, slightly low from that of the reference standard tetracycline
TE30. Furthermore, the synthesized catalysts were extensively characterized
through X-ray diffraction (XRD), Fourier-transform infrared spectroscopy
(FTIR), thermogravimetric analysis (TGA), field emission scanning
electron microscopy (FESEM), and X-ray photoelectron spectroscopy
(XPS) analyses.