title: Investigation of halide-induced aggregation of Au nanoparticles into spongelike gold.
abstract: We present a facile method for fabricating spongelike Au structures by halide-induced aggregation and fusion of gold nanoparticles (AuNPs). Halide ions (F(-), Cl(-), Br(-), and I(-)) showed distinctly different effects on the synthesized AuNPs, which were characterized by localized surface plasmon resonance (LSPR) and dynamic light scattering measurements. A noticeable red-shift in the LSPR peak was found after Br(-) and I(-) ion treatment, which indicates the adsorption of halide atoms or ions on the AuNPs. The surface potential of AuNPs varied by treatment with different types of halides; this finding indicates that different halide ions have different effects on the AuNPs. Br(-) and I(-) ions showed strong affinity toward the AuNPs. The different affinities of halide ions toward the AuNPs play an important role in controlling the formation process of spongelike gold. Citrate ions adsorbed on AuNPs were displaced by halide ions to different extents. Such displacement determined the aggregation and fusion behaviors of the AuNPs and eventually the formation of different spongelike structures.
authors.affiliation: Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences , Suzhou 215163, PR China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhang
authors.forename: Haiwen
authors.initials: H
authors.lastname: Li
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Yihui
authors.initials: Y
authors.lastname: Wu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Guo
authors.forename: Lianqun
authors.initials: L
authors.lastname: Zhou
authors.forename: Jiadong
authors.initials: J
authors.lastname: Li
mesh_terms: D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D006046:Gold