Facile Morphology Control of Ag Core/Pd Shell Metal Nanoparticles with Sodium Citrate for Hydrogen Production from Formic Acid

Abstract

Heterogeneous core/shell nanoparticles are currently of great interest for use as an effective way of hydrogen production from storage materials such as methanol, ethanol, and formic acid. Of various fabrication methods, overgrowth of the secondary metal component on a seed material is one of the most commonly used synthetic methods. However, controlling the mode of overgrowth for a deposited metal is nontrivial and remains challenging. We describe here that utilizing a surface ligand for the growth of the secondary metal component on Ag core can dramatically affect the growth mode of the second metal materials. TEM results showed that the presence of a surface ligand enabled the growth mode of the secondary growing component (Au, Pt, or Pd) on Ag nanoparticles to change from island growth to layered growth, making it possible to synthesize precisely well-controlled core/shell nanoparticle structure.