Submonolayer-Pt-Coated Ultrathin Au Nanowires and Their Self-Organized Nanoporous Film: SERS and Catalysis Active Substrates for Operando SERS Monitoring of Catalytic Reactions

Abstract

For their unique properties, core-shell bimetal nanostructures are currently of immense interest. However, their synthesis is not a trivial work, and most works have been conducted on nanoparticles. We report herein a new synthetic tactic for submonolyer-Pt coated ultrathin Au nanowires (NWs). Besides providing a strong electromagnetic field for Raman signal enhancing, the underlined Au NWs markedly enhanced the catalytic activity of Pt atoms through increasing their dispersity and altering their electronic state. The integration of excellent SERS and high catalytic activity within Au@Pt NWs enable it work as platform for catalyzed reaction study. As a proof of principle, the self-organized Au@Pt NWs thin film is employed in operando SERS monitoring of the p-nitrothiophenol reduction process. In addition to providing kinetic data for structure-activity relationship study, the azo-intermidate independent path is also directly witnessed. This synthetic tactic can be extended to other metals, thus offering a general approach to modulate the physical/chemical properties of both core and shell metals.

Mechanistic study on reduction reaction of nitro compounds catalyzed by gold nanoparticles using in situ SERS monitoring

“…To achieve in situ SERS monitoring, catalytically responsive and SERS active functionalities must be combined into a single platform, which has been realized by assembling SERS active substrates and small metal catalysts [5][6][7][8][9], or coating the SERS active inner core with a catalytic shell [10][11][12][13][14]. Among them, gold-based SERS/catalyst bifunctional systems have been of tremendous interest because gold nanostructures exhibit high SERS activities and superior catalytic properties under mild conditions, which closely depend on their sizes and shapes [15].…”

Self-assembly of plasmonic nanostructures into superlattices for surface-enhanced Raman scattering applications

“…We further extended this method to fabrication of Ag NPF that had an even better SERS performance and allowed detection of high toxicity aflatoxins down to 10 À8 M. Moreover, the bottom-up approach used in (Au/ Ag) NPF fabrication allowed the doping and even distribution of other functional materials into the nanopores, thus conferring them with SERS activity (Fig. 4A) [27,79,80]. The combination of the SERS activity and the functions of the doped materials endows these hybrid SERS substrates with specific functions, which we termed task-specific SERS substrates.…”

“…The combination of the SERS activity and the functions of the doped materials endows these hybrid SERS substrates with specific functions, which we termed task-specific SERS substrates. As a proof-of-concept, we coprecipitated nanosorbent (g-Fe 2 O 3 nanosheets, a good sorbent for inorganic Arsenic ions) and nanocatalyst (Pd overlayer/branches) into Ag NPFs, and successfully performed ultra-sensitive SERS detection of arsenic ions in the presence of a high concentration of coexisting ions and monitored the catalyzed reactions with SERS with a millisecond time resolution [27,33].…”

“…Based on this unexpected discovery, we proposed an in situ SERS method to track the fate of SPR-generated HEs. With this method, Ag pinholes were identified as a key factor for leakage of HEs into the surrounding ions/molecules [27,79,80], including O species like lattice O and surface adsorbed molecular O 2 , which sheds light onto why Ag is seldom employed as a plasmonic co-catalyst and provides a new viewpoint by which to design highly efficient light-utilizing plasmonic nanocatalysts.…”

Pt-Based Nanostructures for Observing Genuine SERS Spectra of p-Aminothiophenol (PATP) Molecules

“…During the past decades, many efforts have been made to break the limitation of substrate specificity and to expand SERS applications to other metals, especially the transition metals Pd and Pt, which are widely used in catalysis [15,21,22]. Recently, it was reported that bimetallic/multiple metallic nanomaterials display novel properties distinct from the pure Pd or Pt element nanostructures [23][24][25][26][27][28].…”