Catalytic Degradation of 4-Nitrophenol in Polluted Water by Three-Dimensional Gold Nanoparticles/Reduced Graphene Oxide Microspheres

Ning Li 1, 2

Fuhua Zhang 1, 2 

 Hua Wang 2, Email

Shifeng Hou 1, 2 

1 School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China

2 National Engineering and Technology Research Center for Colloidal Materials, Shandong University, Jinan, Shandong 250100, China

Abstract

Microspheres as catalysts catalyst supports have attracted a great deal of attention over the last two decades. Here, gold nanoparticles (Au-NPs) encapsulated within the reduced graphene oxide microspheres (rGO microspheres) were prepared by using a spray-drying method. The Au-NPs were distributed evenly through the rGO microsphere composite. The mass content of Au-NPs in the rGO microspheres composite reached 30.3%, and the average size of the Au-NPs was 10.5±2.5 nm. The morphologies and structural characteristics of the materials were determined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) patterns. The as-prepared composite was used to catalyze the reduction of 4-nitrophenol to 4-aminophenol in the presence of excess sodium borohydride and exhibited high catalytic activity. The catalysis process was monitored by UV spectroscopy, and the first order rate constant of the catalytic reaction K was 1.96× 10−3 s-1, and the activation energy Ea was found to be 3.5´ 104 J/mol. The catalytic experiment results indicated the Au/rGO microspheres prepared have a great application for friendly environment aspects.

Catalytic Degradation of 4-Nitrophenol in Polluted Water by Three-Dimensional Gold Nanoparticles/Reduced Graphene Oxide Microspheres