title: Gold nanostars: Benzyldimethylammonium chloride-assisted synthesis, plasmon tuning, SERS and catalytic activity.
abstract: Fabrication of Au nanostars (AuNSs) can expand the application range of Au nanoparticles because of their high electron density and localized surface plasmon resonance (LSPR) on branches. Exploiting this potential requires further refinement of length of the branches and radius of their tips. To this end, we successfully synthesized AuNSs with uniform and sharply-pointed branches by combining benzyldimethylammonium chloride (BDAC) and cetyltrimethylammonium bromide (CTAB) at low BDAC/CTAB ratios. Once mixed with CTAB, BDAC lowers the critical micelle concentration (CMC) for quick formation of the micelles, which provides favorable growth templates for AuNSs formation. Besides, BDAC increases the concentration of Cl(-), which favors Ag(+) in adsorbing on Au facets. This feature is crucial for the yield boosting and synergic shape control of AuNSs regardless of types of Au seeds used. Use of less amounts of seeds as the center of nucleation benefited sharper and longer growth of the branches. AuNSs exhibited excellent enhancement of surface-enhanced Raman scattering (SERS) intensities as the result of high electron density localized at the tips; however, the enhancement degree varied in accordance with the size of branches. In addition, AuNSs showed high catalytic performance toward the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). Efficient catalysis over AuNSs originates from their corners, stepped surfaces and high electron density at the tips.
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), State Key Laboratory of Fine Chemicals, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Pancras
authors.initials: P
authors.lastname: Ndokoye
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), State Key Laboratory of Fine Chemicals, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China; Department of Chemical Engineering, Curtin University, Perth, WA 6845, Australia. Electronic address: xyli@dlut.edu.cn.
authors.forename: Xinyong
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), State Key Laboratory of Fine Chemicals, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Qidong
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), State Key Laboratory of Fine Chemicals, School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Chemical Engineering, Curtin University, Perth, WA 6845, Australia.
authors.forename: Moses O
authors.initials: MO
authors.lastname: Tade
authors.affiliation: Department of Chemical Engineering, Curtin University, Perth, WA 6845, Australia.
authors.forename: Shaomin
authors.initials: S
authors.lastname: Liu
mesh_terms: D000627:Aminophenols / Q000138:chemical synthesis* / Q000737:chemistry; D050339:Benzylammonium Compounds / Q000737:chemistry*; D002384:Catalysis; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008823:Micelles; D009596:Nitrophenols / Q000737:chemistry*; D010316:Particle Size; D013059:Spectrum Analysis, Raman; D013499:Surface Properties
chemical_list: D000627:Aminophenols; D050339:Benzylammonium Compounds; D002593:Cetrimonium Compounds; D008823:Micelles; D009596:Nitrophenols; D006046:Gold; C026729:4-aminophenol; C024836:4-nitrophenol; D000077286:Cetrimonium
keywords: Au nanostars; Benzyldimethylammonium chloride; Catalytic reduction; Plasmon tuning; Surface-enhanced Raman scattering