Speaker
Description
Metallic hollow nanoparticles exhibit interesting optical properties that can be controlled by geometrical parameters [1]. Moreover, irradiation with laser pulses has emerged recently as a valuable tool for reshaping and size modification of plasmonic metal nanoparticles, thereby enabling the synthesis of nanostructures with unique morphologies. In this work, we demonstrate how we can use the irradiation with laser pulses to fabricate hollow nanoparticles. First, we use classical molecular dynamics simulations to investigate the solid-to-hollow conversion of gold nanoparticles upon femtosecond laser irradiation. Based on these results, we suggest an efficient method to produce hollow nanoparticles under certain specific conditions [2]. Moreover, we also demonstrate that the irradiation of spherical nanoparticles with nanosecond laser pulses induces shape transformations yielding nanocrystals with an inner cavity [3]. The concentration of the stabilizing surfactant, the use of moderate pulse fluences, and the size of the irradiated particles determine the efficiency of the process and the nature of the void. Hollow nanocrystals are obtained when molecules from the surrounding medium (e.g., water and organic matter derived from the surfactant) are trapped during laser pulse irradiation. These experimental observations suggest the existence of a subtle balance between the heating and cooling processes experienced by the nanocrystals, which induce their expansion and subsequent recrystallization keeping exogenous matter inside. Therefore, we advance the experimental conditions to efficiently produce hollow nanoparticles, opening a broad range of possibilities for applications in key areas, such as gas and liquid storage and catalysis.
References
(1) Peña-Rodríguez, O.; Pal, U. Exploiting the Tunable Optical Response of Metallic Nanoshells. In UV-VIS and Photoluminescence Spectroscopy for Nanomaterials Characterization; Kumar, C. S. S. R., Ed.; Springer-Verlag: Berlin Heidelberg, 2013; pp 99–149.
(2) Castro-Palacio, J. C.; Ladutenko, K.; Prada, A.; González-Rubio, G.; Díaz-Núñez, P.; Guerrero-Martínez, A.; Fernández de Córdoba, P.; Kohanoff, J.; Perlado, J. M.; Peña-Rodríguez, O.; Rivera, A. Hollow Gold Nanoparticles Produced by Femtosecond Laser Irradiation. J. Phys. Chem. Lett. 2020, 11 (13), 5108–5114. https://doi.org/10.1021/acs.jpclett.0c01233.
(3) González-Rubio, G.; Milagres de Oliveira, T.; Albrecht, W.; Díaz-Núñez, P.; Castro-Palacio, J. C.; Prada, A.; Gonzalez, R. I.; Scarabelli, L.; Bañares, L.; Rivera, A.; Liz-Marzán, L. M.; Peña-Rodríguez, O.; Bals, S.; Guerrero-Martínez, A. Formation of Hollow Gold Nanocrystals by Nanosecond Laser Irradiation. J. Phys. Chem. Lett. 2020, 11 (3), 670–677. https://doi.org/10.1021/acs.jpclett.9b03574.
Acknowledgements
This work has been partly funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) (grants RTI2018-095844-B-I00, PGC2018-096444-B-I00 and MAT2017-86659-R), the Madrid Regional Government (grants P2018/NMT-4389 and P2018/EMT-4437) and EUROFUSION Enable Research project -Advancing shock ignition for direct-drive inertial Fusion- CfP-FSD-AWP21-ENR-01-CEA-02. The authors gratefully acknowledge the computer resources and technical assistance provided by the Centro de Supercomputación y Visualización de Madrid (CeSViMa), as well as the facilities provided by the Center for Ultrafast Lasers at Complutense University of Madrid.
