Stabilization of Various Zero-Valent Metal Nanoparticles on a Superabsorbent Polymer for the Removal of Dyes, Nitrophenol, and Pathogenic Bacteria

Abstract

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.

Melia Azedarach impregnated Co and Ni zero-valent metal nanoparticles for organic pollutants degradation: validation of experiments through statistical analysis

“…After this, 5 mg of Co/MA or Ni/MA was added to the reaction mixture and decrease in the peak intensity at 400 nm was recorded with reaction proceedings. It is worth to mention here that neither dyes nor PNP degraded alone with NaBH 4 as we mentioned in our previous reports that these reactions are thermodynamically favorable but not kinetically [2,10,45,46]. The Co/MA and Ni/MA converted the PNP in 12 min (Fig.…”

“…The resulting suspension was observed for UV-visible measurement in the range of 190-1000 nm. During the course of chemical reaction, a change in the color was observed in PNP or dye solutions [44]. The Co/MA catalytic activity was found highest against the degradation of PNP and MO as compared to Ni/MA; therefore, this catalyst was further used against the discoloration of CR, MB, and RB dyes.…”

“…It may be also possible that hydrogen atoms also get adsorbed on catalysts surface to ensure the reduction reaction. After the addition of NaBH 4 , the reactant converted into its derivatives but the discoloration is occurred by the addition of catalysts [2,29,48,52].…”

“…Environmental pollution is one of the leading problem worldwide affecting human beings and other organisms [1][2][3], and is mainly caused by the natural calamities and anthropogenic activities [4,5]. Rapid urbanization and growth in industrial commercialization is one of the most emerging problems globally [6,7].…”

Cellulose acetate composite films fabricated with zero‐valent iron nanoparticles and its use in the degradation of persistent organic pollutants

“…Initially, the 4NP or dyes was treated with NaBH 4 , but no prominent changes were observed in their absorbance spectrum which suggested that the reaction is kinetically unfavorable. [ 26,32–34 ] Therefore, a catalyst is required to expedite the rate of reaction.…”