title: Facile, template-free synthesis of silver nanodendrites with high catalytic activity for the reduction of p-nitrophenol.
abstract: Here we report a facile, surfactant-free and template-free synthesis process of highly uniform dendritic silver nanostructures with high catalytic activity for the reduction of p-nitrophenol. By controlling the concentration of AgNO(3) aqueous solution and the reaction time, various shapes of silver nanodendrites (SNDs) could be obtained easily. The effects of different parameters such as concentrations of the reagents and reaction time on the morphology and structure of as-prepared tree-like nanostructures have also been investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Also, the X-ray photoelectron spectroscopy (XPS) has been used to identify the oxidation state of SNDs. In addition, the catalytic activity of the as-prepared SNDs samples at 200 mM AgNO(3) aqueous solution was evaluated by a redox reaction of p-nitrophenol in the presence of an excess amount of NaBH(4). It was found that the highly symmetrical SNDs with roughly 60-120 nm in stem and branch diameter and 3-12 μm in length obtained after 120 s reaction time do have higher catalytic activity than other SNDs prepared at different reaction time, several times stronger catalytic activity in the sodium borohydride reduction of p-nitrophenol to p-aminophenol, compared to some other silver nanoparticles reported in literature. The crystallinity provided by X-ray diffraction (XRD) analysis indicates that the improvement of the crystallinity is also very crucial for SNDs' catalytic activities. The SNDs are very promising catalytic candidates for the reduction of p-nitrophenol because of easily simple preparation route and high catalytic activity.
authors.affiliation: State Key Laboratory of Plastic Forming Simulation and Die and Mold Technology, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Fatang
authors.initials: F
authors.lastname: Tan
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Qiu
authors.forename: Xueliang
authors.initials: X
authors.lastname: Qiao
authors.forename: Jianguo
authors.initials: J
authors.lastname: Chen
mesh_terms: D002384:Catalysis; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry*; D009596:Nitrophenols / Q000737:chemistry*; D010084:Oxidation-Reduction; D056951:Photoelectron Spectroscopy; D012834:Silver / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D009596:Nitrophenols; D012834:Silver; C024836:4-nitrophenol