title: Morphology and composition controlled synthesis of flower-like silver nanostructures.
abstract: Flower-like silver nanostructures with controlled morphology and composition were prepared through wet-chemical synthesis. The reaction rate is simply manipulated by the amount of catalyzing agent ammonia added which is the key point to determine the ratio of hexagonal close-packed (HCP) to face-centered cubic (FCC) phase in silver nanostructures. The existence of formic acid that is the oxidation product of aldehyde group is demonstrated to play a crucial role in achieving the metastable HCP crystal structures by replacing ionic surfactants with polyvinylpyrrolidone (PVP). Utilizing flower-like silver nanostructures as surface-enhanced Raman scattering (SERS) substrates, Raman signal of Rhodamine 6G, or 4-aminothiophenol with concentration as low as 10(-7) M was detected. Moreover, it is demonstrated that phase composition has no direct relation to the SERS enhancing factor which is mainly determined by the amount of hot spots.
authors.affiliation: State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China ; Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China ; Cyrus Tang Center for Sensor Materials and Applications, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Li
authors.affiliation: State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China.
authors.forename: Deren
authors.initials: D
authors.lastname: Yang
keywords: Flower-like; Hexagonal close-packed; Overgrowth; SERS; Silver nanostructure