Kinetics of Spontaneous Bimetallization between Silver and Noble Metal Nanoparticles

Abstract

A physical mixture of polymer-protected Ag nanoparticles and Rh, Pd, or Pt nanoparticles spontaneously forms Ag-core bimetallic nanoparticles. The formed nanoparticles were smaller than the parent Ag nanoparticles. In the initial process of this reaction, the surface plasmon absorption of Ag nanoparticles diminished and then almost ceased within one hour. Within several minutes, the decrease in Ag surface plasmon absorption could be analyzed by second-order reaction. This reaction was accelerated with an increase of temperature and the energy gap in the Fermi level between Ag and the other metals. The activation energy (E ) of this reaction could be determined. An electron transfer reaction from Ag to other metal nanoparticles was proposed as the initial interaction between these metal nanoparticles because the Fermi level of Ag is relatively high, and the electron transfer is possible in terms of energy. The Marcus plot between the rate constant and the driving force, roughly estimated from the work function of metals, and the observed E values reasonably explained the proposed electron transfer mechanism.

Au–Ag Nanoflower Catalysts with Clean Surfaces for Alcohol Oxidation

“…Noble‐metal nanocrystals (NCs) are very important for applications in fields such as electrochemistry, electronics, magnetic storage, catalyst, and biotechnology . The properties of a metal NC are dependent on its morphology, including size and shape .…”

“…Noble-metal nanocrystals (NCs) are very important for applications in fields such as electrochemistry,e lectronics, magnetic storage, catalyst, andb iotechnology. [1][2][3][4][5][6][7][8][9][10][11][12][13] The properties of a metal NC are dependento ni ts morphology, including size and shape. [1][2][3][4][5][6] Therefore, many methods for the preparation of NCs with various shapes, such as nanoflowers, [14][15][16][17] nanocubes, [18][19][20][21] nanorods, [22][23][24] and nanowires, [25][26][27][28][29][30][31] with the desired properties have been reported.…”

Surface Plasmon Resonance‐Enhanced Visible‐NIR‐Driven Photocatalytic and Photothermal Catalytic Performance by Ag/Mesoporous Black TiO2 Nanotube Heterojunctions

“…[1][2][3] Al arge number of poisonous and harmful compounds are released into the environment because of lack of effective methods fort reatingt hese pollutants. [4][5][6] Photocatalysis is ap otentialt echnology for solving environmental and energy problemsi ncluding degradation of pollutants, H 2 productionvia water splitting and dye-sensitized solar cell, and selective oxidation reactions. [7][8][9][10][11][12] However,t his strategy remains inefficient due to the challenge: difficultiesi ne nergy band configuration limit sunlight utilization to mainly within the ultraviolet and visible light region, resulting in near-infrared light (NIR, 54 %o fs olar radiation at the Earth's surface) unable to be harvested.…”

Subnano‐Sized Pt–Au Alloyed Clusters as Enhanced Cocatalyst for Photocatalytic Hydrogen Evolution

“…Therefore, it is necessary to introduce a second metal into Pt‐based catalysts by forming an alloyed structures to improve their catalytic activity. Recently, it has been reported that Pt–Ag, Pt–Cu, Pt–Pd and Pt–Au bimetallic catalysts exhibit better catalytic performance than pure Pt catalysts in many research fields . Among them, Pt–Au bimetallic catalysts have aroused intensive research.…”

“…Recently,i th as been reported that Pt-Ag, Pt-Cu, Pt-Pd and Pt-Au bimetallic catalysts exhibit better catalytic performance than pure Pt catalysts in many research fields. [14][15][16][17] Among them, Pt-Au bimetallic catalysts have aroused intensiver esearch. For example, Yang et al have fabricated heterostructures of Pt on Au nanoparticles,w hich showedh igh activity in catalyzing the formic acid oxidation.…”