Pulsed laser ablation based synthesis of colloidal metal nanoparticles for catalytic applications.

Nowadays, metal nanoparticles (NPs) have been considered as highly promising functional materials, impacting virtually all the fields of science and technologies. Numerous wet-chemical approaches have been developed to synthesize metal NPs with various components and structures. Although successful, impurities, such as additives and reaction residuals, usually remain in products. Recently, an alternative method, pulsed laser ablation in liquid (PLAL) phase has attracted increasing attention for colloidal NP preparation, since it can realize a chemical-free environment, leading to the formation of a "clean" NP dispersion. This unique feature makes the PLAL method and resulting metal NPs extremely attractive for catalytic applications, since catalytic reaction efficiency is strongly dependent on the surface feature of metal NPs. Usually, a surfactant-free, "bare" metal surface is highly desired for catalysis as it favors the access of the reactants to the surface active sites of metal NPs. Due to the absence of ligand or stabilizer molecules on the surface of PLAL-NPs, it is expected that these PLAL-NPs can exhibit higher catalytic activity in comparison to their chemically synthesized counterparts. In this review, we briefly introduce some recent advances on the synthesis of PLAL-metal NPs and some of their important catalytic applications.