Pt-based composite nanoparticles for magnetic, catalytic, and biomedical applications

This feature article highlights the recent advances in the synthesis of Pt-based binary alloy and core-shell nanoparticles (NPs) for magnetic, catalytic and biomedical applications. These composite NPs are made by thermal decomposition and reduction of metal precursors in a high boiling point organic solvent with their size, shape, composition and shell thickness controlled by metal precursor concentrations, surfactant concentrations and reaction temperatures. The as-synthesized alloy NPs adopt typically the face centered cubic (fcc) structure and can be further converted into the face centered tetragonal (fct) structure upon high temperature annealing. The NP size, shape, composition and structure dependent magnetism and catalysis are further illustrated. The studies show that the fct structured NPs are ferromagnetic and are promising components for magnetic data storage media, and that the core-shell NPs are better catalysts for fuel cell reactions with much enhanced activity and durability, and that the fcc structured FePt NPs have great potential for multimodality imaging and for therapeutic applications.