title: One-pot green synthesis of silver/iron oxide composite nanoparticles for 4-nitrophenol reduction.
abstract: Silver/iron oxide composite nanoparticles have been synthesized successfully via a facile one-pot green route by the use of l-arginine, which created an aqueous solution of about pH 10 and acted as a reducing agent for the successive formation of iron oxide and Ag nanoparticles. The product was characterized to be silver-coated iron oxide and iron oxide hydroxide composite nanoparticles with a mean diameter of about 13.8 ± 3.0 nm and 8.53% of Ag in weight. It exhibited good catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol with sodium borohydride. The reduction reaction followed the pseudo-first-order kinetics. The corresponding rate constants increased with the increases of temperature and catalyst amount but decreased with the increase of initial 4-NP concentration, revealing an activation energy of 28.2 kJ/mol and a diffusion controlled mechanism. In addition, this product had quite good stability. No significant activity loss was observed after reuse for 5 cycles.
authors: Department of Chemical Engineering, National Cheng Kung University, Tainan, 701, Taiwan.
authors: Jau-Rung
authors: JR
authors: Chiou
authors: Bo-Hung
authors: BH
authors: Lai
authors: Kai-Chih
authors: KC
authors: Hsu
authors: Dong-Hwang
authors: DH
authors: Chen
mesh_terms: D001120:Arginine / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D055772:Green Chemistry Technology; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D009596:Nitrophenols / Q000737:chemistry*; D010084:Oxidation-Reduction; D012834:Silver / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D005290:Ferric Compounds; D009596:Nitrophenols; D014874:Water Pollutants, Chemical; C000499:ferric oxide; D012834:Silver; D001120:Arginine; C024836:4-nitrophenol