Facile Synthesis of Silver Nanoparticles Stabilized by Cationic Polynorbornenes and Their Catalytic Activity in 4-Nitrophenol Reduction

Abstract

Baruah B, Gabriel GJ, Akbashev MJ, Booher ME. 2013. Facile synthesis of silver nanoparticles stabilized by cationic polynorbornenes and their catalytic activity in 4-nitrophenol reduction. Langmuir 29(13):4225-34. ABSTRACT: We report the facile one-pot single-phase syntheses of silver nanoparticles stabilized by norbornene type cationic polymers. Silver nanoparticles (AgNPs) stabilized by polyguanidino oxanorbornenes (PG) at 5 and 25 kDa and polyamino oxanorbornenes (PA) at 3 and 15 kDa have been synthesized by the reduction of silver ions with NaBH 4 in aqueous solutions at ambient temperature. The four different silver nanoparticles have been characterized by UV−vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and transmission electron microscopy (TEM) for their particle size distributions. Interestingly, PG stabilizes the silver nanoparticles better than PA as evident from our spectroscopic data. Furthermore, the AgNP-PG-5K (5K = 5 kDa) was found to serve as an effective catalyst for the reduction of 4-nitrophenol to 4-aminophenol in the presence of NaBH 4 . The reduction has a pseudo-first-order rate constant of 5.50 × 10 −3 s −1 and an activity parameter of 1375 s −1 g −1 , which is significantly higher than other systems reported in the literature.

Synthesis and anti-fungal effect of silver nanoparticles–chitosan composite particles

“…Stabilizers such as surfactants, micelles, ligands, and polymers have been widely utilized in the literature. [17][18][19][20] Recently, incorporating metal nanoparticles into polymers has been proposed. Immobilizing metal nanoparticles on matrix polymers called nanometal polymer hybrids efficiently prevents nanoparticles' aggregation.…”

Single Metal of Silver Nanoparticles in the Microemulsion for Recyclable Catalysis of 4-Nitrophenol Reduction

“…As expected, a linear relationship between ln(A t /A 0 ) and reaction time was obtained. Thus, the rate constant was estimated from the slop of the best-fit line as ca.0.59 min -1 , which was much higher than that of other catalysts reported elsewhere (Table 1) [1,30,[37][38][39][40][41][42]. Due to the fact that our catalyst was of low cost, easy to synthesize, and highly efficient, it was beneficial over those from other reports.…”

“…The size and morphology of Ag NPs were highly controlled by microemulsion, which were obtained a granulum structure with a diameter of 540-640 nm. The Ag NPs exhibited high catalytic activity in the reduction of 4-NP in the presence of NaBH 4 , as a result of the high surface area and electronic properties of Ag NPs supports. Excellent reproducibility and stability were further confirmed.…”

“…The UV-vis absorption spectra were then recorded at RT in a scanning range of 250-500 nm. For studying the effect of catalyst dose, the amount of Ag NPs catalyst was varied 0.01 g-0.03 g; however, volume and concentration of 4-NP and NaBH 4 were kept constant (20 mL of 2 mM and 20 mL of 0.25 M, respectively). In a similar way, the temperature was varied 0-95°C.…”

“…Herein, BH 4 -was adsorbed onto the surface of Ag NPs to react and transfer electrons to Ag NPs [30]. And then the bare Ag NPs serve as catalyst to transfer electrons from BH 4 -to nitrophenols, leading to the production of amino derivatives, 2-amion-4-nitrophenol and p-aminophenol [49]. …”