title: Two-dimensional structure Au nanosheets are super active for the catalytic reduction of 4-nitrophenol.
abstract: Two-dimensional structure Au nanosheets with a polygon morphology and controlled thicknesses of ∼15 nm, ∼35 nm, and ∼50 nm were successfully synthesized by a one-step solution reduction method. Scanning and transmission electron microscopy (SEM and TEM), selected area electron diffraction (SEAD) analyses, and X-ray diffraction (XRD) were used to thoroughly study the structure and the formation mechanism of the nanosheets. The catalytic activity of the Au nanosheets was investigated for the reduction of 4-nitrophenol (4-NP) by UV-visible absorption spectroscopy. Against all expectation, the Au nanosheets with such a big lateral (more than 1 μm) size exhibited superior catalytic activity on the selective reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of NaBH4. On the other hand, the catalytic activity does closely depend on the thickness of the nanosheets; that is, it decreases with increasing thickness. The reaction can be completed in less than 1 min when catalyzed by Au nanosheets about 15 nm thick. The 100% conversion efficiency was further demonstrated after two catalytic cycles with the thinnest Au nanosheets.
authors.affiliation: School of Chemistry and Environment, Beihang University, Beijing 100191, P. R. China. lilidong@buaa.edu.cn guolin@buaa.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Cui
authors.forename: Lidong
authors.initials: L
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
authors.forename: Shihe
authors.initials: S
authors.lastname: Yang