title: Reversibly Switching Silver Hierarchical Structures via Reaction Kinetics.
abstract: Here we report a study on controllable synthesis of hierarchical silver structures via regulating reaction kinetics. Silver particles with various morphologies are synthesized by a solution-based reduction approach at the addition of amino acids. The amino acid is used to coordinate with silver ions to slow down the reduction of silver ions. With the increase of glycine concentration, the morphologies of silver particles switch from dendrites, to flowers and to compacted spheres, which is attributed to the decrease of reaction rate as a result of the coordination. Three more amino acids are examined and confirms the role of reaction kinetic in shaping silver particles. Furthermore, by increasing the concentration of the reductant, the silver morphologies change from compact spheres to loose flowers as a result of the increase of reaction rate. Therefore the silver hierarchical structure can be reversibly switched by reaction kinetics. The silver particles synthesized are tested for surface enhanced Raman scattering (SERS) property and the dendritic particles present a remarkable SERS activity. This study shows that reaction kinetics is a powerful tool to tune hierarchical structures of silver particles, which is expected to be transferable to other material systems.
authors.affiliation: Institute of Materials Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Jianmei
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Chengxiang
authors.initials: C
authors.lastname: Li
authors.affiliation: Institute of Materials Science and Engineering, Ocean University of China, Qingdao, 266100, China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Dai
authors.affiliation: State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Han