Alternative Local Melting‐Solidification of Suspended Nanoparticles for Heterostructure Formation Enabled by Pulsed Laser Irradiation

Abstract

Phase formation by pulsed laser irradiation of suspended nanoparticles has recently been introduced as a promising synthesis technique for heterostructures. The main challenge still lingers regarding the exact mechanism of particle formation due to the non‐equilibrium kinetic by‐products resulting from the localized alternative, fast, high‐temperature nature of the process. Here, the authors analyze the bond breaking/formation of copper or copper (II) interfaces with ethanol during the absorption of pulses for Cu‐CuO‐Cu2O formation applicable as an electrocatalyst in ethanol oxidation fuel cells. This study includes but is not limited to, a comprehensive discussion of the interaction between nano‐laser pulses and suspension for practical control of the synthesis process. The observed exponential and logarithmic changes in the content of heterostructures for the CuO‐ethanol and Cu‐ethanol samples irradiated with different fluences are interpreted as the dominant role of physical and chemical reactions, respectively, during the pulsed laser irradiation of suspensions synthesis. It is also shown that the local interface between dissociated ethanol and the molten sphere is responsible for the oxidative/reductive interactions resulting in the formation of catalytic‐augmented Cu3+ by‐product, thanks to the reactive bond force field molecular dynamics studies confirmed by ab‐initio calculations and experimental observations.

Controlling the Magnetic Properties of Fe-Based Composite Nanoparticles

“…A big role is played here by the interaction between the solvent and the solid phase, started by the absorption of ethyl acetate on the solid surface [22]. Figure 5a, b shows the top and three-dimensional side views of the simulation model.…”

“…The irradiated material melts and subsequently merges to form submicrometer-sized spherical particles. The latter technique, referred to as pulsed laser irradiation in liquids (PLIL), proved to be a comprehensive and promising method for the synthesis of colloidal submicrometer spheres with outstanding properties [20][21][22][23][24][25][26][27][28][29][30][31]. So far, it has been shown to be an effective approach for the synthesis and control of a variety of composite particles with various morphology (core-shell, alloy) and compositions, which are not only metals or oxides, but also non-equilibrium bimetallic alloys (AuFe, AuCo, and AuNi).…”

Laser synthesis of nanoparticles in organic solvents – products, reactions, and perspectives

“…In catalysis, the protection of the active sites against oxidation or nanoparticle surface segregation requires organic liquids as well. Here, liquids such as propylene carbonate [ 186 ], ethanol [ 125 – 126 ], or acetone [ 86 , 97 – 98 ] are required. An emerging field in electrocatalysis is the synthesis of high-entropy alloy (HEA) nanoparticles or compositionally complex alloy nanoparticles (for nomenclature, refer to [ 187 ]).…”