Characterization of the coating structure and stability of core–shell Al nanoparticles generated by using pulsed laser ablation in acetone

Al nanoparticles are of significant interest due to their enhanced energetic properties and applicability in optics, biology, and the energy industry. We demonstrate the synthesis of core–shell Al nanoparticles via pulsed-laser-ablation-in-liquid, which reduces oxide formation and increases their resistance to reactive environments. When a bulk Al target was ablated in an organic solvent (acetone), high purity nanoparticles with a high Al content in the core part were generated. The size of the nanoparticles (6–7 nm) was not significantly changed according to the experimental conditions. However, low laser energy intensity is preferable due to less aggregation of nanoparticles and low impurity content. Amorphous and graphite carbon species were found in the coating of the core–shell Al nanoparticles. In addition, we show evidence of enolates or carboxylates in the coating material, as evidenced via energy dispersive spectroscopy and Fourier-transform infrared spectroscopy. Aging experiments in deionized water revealed that the passivated Al nanoparticles could maintain high purity in the core part and high stability in reactive environments such as water.