Room-temperature synthesis and enhanced catalytic performance of silver-reduced graphene oxide nanohybrids
The synthesis of supported, ultrasmall metallic nanoparticles (NPs) is of great importance for catalytic applications. In this study, silver-reduced graphene oxide nanohybrids (Ag–rGO NHs) were prepared by reducing Ag ions and graphene oxide (GO) at room temperature using sodium borohydride (NaBH4) and trisodium citrate. The resulting products were characterized using UV–Vis spectroscopy, X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy. The rich chemistry of GO surface provided many sites for the nucleation of Ag ions and efficiently limited their growth. Ag NPs were uniformly grown on basal planes of rGO with a high density (~1,700 NPs μm−2) and well-defined size (3.6 ± 0.6 nm) as evidenced in SEM and HRTEM studies. The resulting Ag–rGO NHs were readily dispersed in water and exhibited enhanced catalytic activity toward the reduction of 4-nitrophenol by NaBH4 in comparison to unsupported Ag NPs. The role of rGO as an excellent support for Ag catalyst is discussed.
KeywordsGraphene oxide Silver nanoparticles Nanohybrids Catalysis
This study was supported by a start-up Grant from the Electronics-Inspired Interdisciplinary Research Institute (EIIRIS) at Toyohashi University of Technology, Japan. The authors would like to thank Prof. Atsunori Matsuda, Dr. Ryugo Tero, Dr. Naoko Yoshida, Dr. Yuu Hirose and Mr. Hirokazu Muramoto of Toyohashi University of Technology for their support in experimental facilities and characterizations of materials. Ito Kokuen Co. Ltd. is thanked for providing graphite flakes.
Conflict of interest
The authors declare no competing financial interest.
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