In situ immobilization of ultra-fine Ag NPs onto magnetic Ag@RF@Fe3O4 core-satellite nanocomposites for the rapid catalytic reduction of nitrophenols. (15th July 2020)

• Record Type: Journal Article
• Authors: Cao, Hai-Lei; Liu, Cheng; Cai, Feng-Ying; Qiao, Xing-Xing; Dichiara, Anthony B.; Tian, Chungui; Lü, Jian
• Is Part Of: Water research. Volume 179(2020)
• Publication Date: 2020-07-15
• Subjects: Nitrophenol reduction -- Silver nanoparticles -- Magnetic nanocomposite -- Core-satellite structure -- Kinetic and thermodynamic study; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2020.115882
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Novel magnetic Ag@RF@Fe3 O4 core-satellite (MCS) nanocomposites were prepared through in situ photoreduction upon bridging Fe(III) and Ag + via hydroxyl groups in resorcinol formaldehyde (RF) resin by virtue of the coordination effect. The catalytic activity of MCS nanocomposites was evaluated based on catalytic 4-nitrophenol (4-NP) reduction with NaBH4 as the reducing agent. It was noteworthy that the MCS-3 was beneficial to obtain a superior reaction rate constant of 2.27 min −1 and a TOF up to 72.7 h −1 . Moreover, the MCS could be easily recovered by applying an external magnetic field and was reused for five times without significantly decrease in catalytic activity. Kinetic and thermodynamic study revealed that catalytic 4-NP reduction using MCS nanocatalysts obeyed the Langmuir-Hinshelwood mechanism and was controlled by the diffusion rate of substrates. Overall, the immobilization of ultra-fine Ag nanoparticles and the extremely negative potentials around MCS nanocomposites, which were effective for the diffusion of reactants, synergistically accelerated the catalytic reduction reactions. Graphical abstract: Image 1 Highlights: Ag NPs immobilized onto magnetic core-satellite nanocomposites were prepared. The nanocatalyst showed a superior rate constant of 2.27 min −1 in 4-NP reduction. The nanocatalyst exhibited considerable activity towards nitrophenol derivatives.