Rational strategy for shaped nanomaterial synthesis in reverse micelle reactors.
The shape-controlled synthesis of nanoparticles was established in single-phase solutions by controlling growth directions of crystalline facets on seed nanocrystals kinetically; however, it was difficult to rationally predict and design nanoparticle shapes. Here we introduce a methodology to fabricate nanoparticles in smaller sizes by evolving shapes thermodynamically. This strategy enables a more rational approach to fabricate shaped nanoparticles by etching specific positions of atoms on facets of seed nanocrystals in reverse micelle reactors where the surface energy gradient induces desorption of atoms on specific locations on the seed surfaces. From seeds of 12-nm palladium nanocubes, the shape is evolved to concave nanocubes and finally hollow nanocages in the size ~10 nm by etching the centre of {200} facets. The high surface area-to-volume ratio and the exposure of a large number of palladium atoms on ledge and kink sites of hollow nanocages are advantageous to enhance catalytic activity and recyclability.
Department of Chemistry and Biochemistry, City University of New York, Hunter College, 695 Park Avenue, New York, New York 10065, USA.
Zengyan
Z
Wei
Department of Chemistry and Biochemistry, City University of New York, Hunter College, 695 Park Avenue, New York, New York 10065, USA.
Hiroshi
H
Matsui
D053768:Metal Nanoparticles; D008823:Micelles; D049329:Nanostructures; D010165:Palladium; D013499:Surface Properties; D013816:Thermodynamics
D008823:Micelles; D010165:Palladium