Substitutional Platinum-Phosphorus Solid Solution by Phosphidation of Worm-Like Pt Nanoparticles Using...

Area of Science:

• Materials Science
• Nanotechnology
• Solid-State Chemistry

Background:

• Platinum nanoparticles are crucial in catalysis and electronics.
• Controlling nanoparticle composition at the atomic level is challenging.
• Phosphidation often leads to surface encapsulation or distinct phases.

Purpose of the Study:

• To investigate the phosphidation of platinum nanoparticles using tri-n-octylphosphine (TOP).
• To explore the formation of substitutional platinum-phosphorus (Pt-P) solid solutions.
• To determine the stability and maximum phosphorus content in the Pt-P solid solution.

Main Methods:

• Synthesis of platinum nanoparticles.
• Phosphidation using tri-n-octylphosphine (TOP) at elevated temperatures in an organic solvent.
• Characterization using various techniques (e.g., X-ray diffraction, electron microscopy, spectroscopy).
• Density functional theory (DFT) calculations to validate experimental findings.

Main Results:

• Discovery of a unique phenomenon: phosphorus atoms replacing platinum atoms in the lattice.
• Formation of a substitutional Pt-P solid solution.
• Experimental and computational evidence confirming the substitutional doping.
• Determination that the maximum stable P content is approximately 10% while maintaining the face-centered cubic structure.

Conclusions:

• Substitutional Pt-P solid solutions can be formed by doping platinum nanoparticles with phosphorus.
• The face-centered cubic crystal structure remains stable up to ~10% P content.
• This finding offers new possibilities for tuning platinum nanoparticle properties.