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Updated: Jun 2, 2026
07:14
Synthesis of Bimetallic Pt/Sn-based Nanoparticles in Ionic Liquids
Published on: August 23, 2018
Size-, shape- and composition-dependent alloying ability of bimetallic nanoparticles
Shiyun Xiong1, Weihong Qi, Baiyun Huang
1School of Materials Science and Engineering, Central South University, Changsha, 410083, China.
Summary
Bimetallic nanoparticle formation energy decreases with size and increasing temperature. Below a critical size, nanoparticles exhibit negative formation enthalpy, enabling alloying across all compositions, unlike bulk materials.
Area of Science:
- Materials Science
- Nanotechnology
- Physical Chemistry
Background:
- Understanding the thermodynamic stability of bimetallic nanoparticles is crucial for designing novel materials.
- Bulk immiscible systems present challenges in achieving alloyed nanoparticles, necessitating size and shape effect considerations.
Purpose of the Study:
- To develop a surface-area-difference model for calculating formation enthalpies and Gibbs free energies of bimetallic nanoparticles.
- To investigate the influence of size, shape, and temperature on the alloying behavior of bimetallic nanoparticles.
- To establish composition-critical size diagrams for bulk immiscible bimetallic nanoparticle systems.
Main Methods:
- Utilized a surface-area-difference model to calculate thermodynamic properties.
- Considered particle size and shape effects in the calculations.
- Generated composition-critical size diagrams for various bimetallic systems.
Main Results:
- Both formation enthalpy and Gibbs free energy decrease with decreasing particle size.
- Increased temperature mimics the effect of decreased particle size on Gibbs free energy.
- Negative formation enthalpy is observed for particles below a critical size, facilitating alloying.
- Alloying progresses from dilute to dense solute regions as particle size decreases.
- Composition-critical size diagrams reveal distinct non-alloying, alloying, and possible alloying regions.
Conclusions:
- The developed model accurately predicts the thermodynamic behavior and alloying of bimetallic nanoparticles.
- Size and temperature are critical factors controlling the formation energy and alloying in bimetallic nanoparticles.
- Model predictions align well with experimental and simulation data for systems like Cu-Ag, Au-Ni, Ag-Pt, and Au-Pt.
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