Microwave-Assisted Synthesis of Metallic Nanomaterials in Liquid Phase

Metallic nanoparticles are one of the fundamental materials in nanoscience and nanotechnology because they gave novel optical, electronic, magnetic, and catalytic properties, different from those of bulk metals. Since these unique properties depend on shape, size, and composition of nanoparticles, their controlled syntheses are required. Among many synthesis methods of metallic nanoparticles in liquid phase, microwave (MW)-assisted syntheses recently received a great attention because shape- and size-selective syntheses of nanoparticles are possible in a shorter overall processing time than those in the conventional oil-bath heating. This minireview is not meant to give an exhaustive overview of all metallic nanoparticles synthesized by MW heating, but to represent principles and advantage of MW-assisted processes from recent representative researches. I especially focus on preparation and application of core-shell type hybrid particles, which have unique chemical, physical, and optical properties, different from monometallic nanoparticles. Specific roles of MW irradiation in the formation of metallic nanoparticles are discussed.