Large scale fabrication of nanomaterials for energy research
Stephan Barcikowski, Universität Duisburg-Essen, Essen, Germany
Pure inorganic nanoparticles without ligands or stabilizers fabricated by laser ablation in liquid are promising materials for energy converting materials like heterogeneous catalysts or hydrogen storage materials . Especially in case of heterogeneous catalysts, common preparation techniques like impregnation or colloidal deposition are usually accompanied by extensive use of chemical precursors, stabilizers and ligands that may result in catalysts poising.
In our recent work, we showed how to synthesize colloidally stable and size-controlled nanoparticles made of catalytic active materials (e.g. Pt, Au, Pd, Ni). For this purpose, an intensive pulsed laser beam is focused onto an immersed target of chosen nanoparticle material. Properties of pure, colloidal nanoparticles like particle size can be controlled by use of saline solutions . These colloidal particles can be supported by attractive electrostatic interactions to carrier structures like metal oxides and carbon allotropes for synthesis of heterogeneous catalysts . First catalytic testing of laser-generated nanomaterials has proved their potential as active and stable catalysts.
In this work, we present a strategy to further scale up the process by enhancing the productivity of the synthesis. The approach utilizes a high-repetition rate laser system consisting of a 500W ps-laser source and a laser scanner that reaches a scanning speed of up to 500m/s. This unique system spatially bypasses shielding entities and thereby applies most of the laser energy to the target leading to productivities of up to 4 gram colloidal nanoparticles per hour demonstrated in a continuous process .
 S. Barcikowski, G. Compagnini, Phys. Chem. Chem. Phys. 5, 3022 (2013).
 V. Merk, C. Rehbock, F. Becker, U. Hagemann, H. Nienhaus, S. Barcikowski, Langmuir 5, 4213 (2013).
 G. Marzun, C. Streich, S. Jendrzej, S. Barcikowski, P. Wagener, Langmuir 30, 11928 (2014).
 R. Streubel, S. Barcikowski, B. Gökce, Opt. Lett. (2016), accepted