Chemically clean synthesis and characterization of graphene oxide‐poly(acrylic acid–sodium styrene sulfonate) composite thermostable elastic gel encapsulating copper nanoparticles for efficient catalytic reduction of 4‐nitrophenol

Abstract

The thermostable chemically blended elastic poly‐(acrylic acid–sodium‐styrene‐sulfonate–graphene oxide) super‐absorbent hydrogel was synthesized by additive‐free gamma‐radiation induced polymerization followed by crosslinking method. It showed the best swelling ratio in water due to its porous nature. The composite material adsorbed 98 mg/g Cu(II) at room temperature from the aqueous solution of Cu(II) at pH 5 by the chemi‐adsorption of Cu(II) ions at several energetically heterogeneous functional groups. The copper nanoparticles (CuNPs) of size 12 ± 8 nm had been synthesized in situ by chemical reduction of the pre‐adsorbed Cu(II) ions. The functional groups of composite hydrogel served as complexing agent and nano‐reaction sites. Avoiding any pre‐reduction induction time, the inexpensive CuNPs catalytically completely decolorized the aqueous solution of 4‐nitrophenol (4‐NP) within 60 s in the presence of NaBH4 at a promising calculated rate constant (9.0 × 10−2/s) ever reported in the literatures. It is in contrast to the commonly noticeable phenomenon for other CuNPs‐based catalysis of 4‐NP. The composite hydrogel matrix helped to retain the catalytic activity of CuNPs and simultaneously it helped in the osmotic inclusion of 4‐NP into the reaction cites. This composite hydrogel synthesized through a chemically clean method could be utilized for efficient conversion of hazardous chemical 4‐NP to industrially important chemical 4‐aminophenol. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46200.

Cu Nanoparticles Supported on Oxygen-Rich Boron Nitride for the Reduction of 4-Nitrophenol

“…The compositional and morphological features of BNO would benefit the dispersion of metal nanoparticles and could provide sufficient active sites in catalytic reactions. Copper nanoparticles, a typical nonprecious metal with high catalytic activity for hydrogenation − and reduction of NO x , − were loaded to the BNO support via a simple adsorption–reduction procedure. − Our results show that Cu nanoparticles are well dispersed on the BNO surface with an average particle size of 5 nm. The catalytic performance of as-synthesized Cu/BNO catalyst was investigated by the reduction of p -nitrophenol (4-NP) in the presence of NaBH 4 .…”

Classification, synthesis, characterization, and applications of metal nanoparticle-containing hybrid microgels: a comprehensive review

“…More content will be absorbed if opposite charges are present on both the adsorbate and adsorbent. 66,76,77,138,[218][219][220][221][222][223] In this way selectivity can also be created in the hybrid microgel systems for the adsorption of specic pollutants, because the hybrid microgels will repel pollutants if the same charge is present on both. Mostly, the adsorption of pollutants by hybrid microgels is monitored by UV-Visible spectrophotometry (for all types of pollutants) or atomic adsorption spectrophotometry (only for metal ions).…”

“…More content will be absorbed if opposite charges are present on both the adsorbate and adsorbent. 66,76,77,138,218–223…”

Recent developments in hydrogels containing copper and palladium for the catalytic reduction/degradation of organic pollutants

“…1 ). 83 The composite material adsorbed 98 mg g −1 copper( ii ) from an aqueous solution of copper( ii ) at room temperature at pH 5 with the chemi-adsorption of copper( ii ) ions by its various functional groups with high energy. Through the chemical reduction of the pre-adsorbed copper( ii ) ions, Cu NPs with a size of 12 ± 8 nm were prepared in situ .…”