Electroless deposition of Au around electrochemically evolved hydrogen bubbles

In this report, we use stripe-patterned substrates and TEM grids as working electrodes to demonstrate that electrochemically evolved hydrogen bubbles can serve as templates and reducing agents for electroless deposition of Au from a Na3Au(SO3)2 electrolyte to form hollow particles. This new hollow nanoparticle formation mechanism, which is termed as bubble template synthesis, has the potential to become a general route to the fabrication of various metallic hollow nanoparticles. We have also found that the addition of Ni2+ ions in the electrolyte has an effect on the particle formation process. Electrodeposited metallic Ni enhances the hydrogen evolution and therefore the hollow particle formation. It also leads to an improved size distribution of the hollow particles.