Vapor-phase synthesis of metallic and intermetallic nanoparticles and nanowires:Magnetic and catalytic properties

摘要

In this paper,we present several examples of the vapor-phase synthesis of inter-metallic and alloy nanoparticles and nanowires,and investigate their magnetic and catalytic properties.In the first example,we report the vapor-phase synthesis of intermetallic alu-minide nanoparticles.Specifically,FeAl and NiAl nanoparticles were synthesized via laser vaporization controlled condensation (LVCC)from their bulk powders.The NiAl nanoparti-cles were found to be paramagnetic at room temperature,with a blocking temperature of ap-proximately 15 K.The FeAl nanoparticles displayed room-temperature ferromagnetism.In the second example,we report the vapor-phase synthesis of cobalt oxide nanoparticle cata-lysts for low-temperature CO oxidation.The incorporation of Au and Pd nanoparticles into the cobalt oxide support leads to significantly improved catalytic activity and stability of the binary catalyst systems.Finally,we report the synthesis of nanowires of Ge,Mg,Pd,and Pt using the vapor-liquid-solid (VLS)method where the vapor-phase growth of the wire is cat-alyzed using a proper metal catalyst present in the liquid phase.