Shape-Controlled Synthesis of Single-Crystalline Palladium Nanocrystals

Abstract

A versatile method for selectively synthesizing single-crystalline rhombic dodecahedral, cubic, and octahedral palladium nanocrystals, as well as their derivatives with varying degrees of edge- and corner-truncation, was reported for the first time. This is also the first report regarding the synthesis of rhombic dodecahedral palladium nanocrystals. All the nanocrystals were readily synthesized by a seed-mediated method with cetyltrimethylammonium bromide as surfactant, KI as additive, and ascorbic acid as reductant. At the same ascorbic acid concentration, a series of palladium nanocrystals with varying shapes were obtained through manipulation of the concentration of KI and the reaction temperature. The formation of different palladium facets were correlated with their growth conditions. In the absence of KI, the 100 palladium facets are favored. In the presence of KI, the concentration of KI and the reaction temperature play an important role on the formation of different palladium facets. The 110 palladium facets are favored at relatively high temperatures and medium KI concentrations. The 111 palladium facets are favored at relatively low temperatures and medium KI concentrations. The 100 palladium facets are favored at either very low or relatively high KI concentrations. These correlations were explained in terms of surface-energy and growth kinetics. These results provide a basis for gaining mechanistic insights into the growth of well-faceted metal nanostructures.

CeO2-encapsulated noble metal nanocatalysts: enhanced activity and stability for catalytic application

“…[1][2][3][4][5][6][7][8][9][10] With the help of noble metal catalysts, environmental friendly catalysis resulting in the decreased production of pollutants, waste minimization and new synthetic routes that circumvent modern synthetic techniques such as Sonogashira-, Heck-and Miyaura-Suzuki-type reactions can be easily realized. [11][12][13][14][15] However, for most technologically important chemical processes, noble metal catalysts spontaneously aggregate and grow to reduce the surface energy, which limits the catalysts' lifetime and efficiency.…”

Understanding of the major reactions in solution synthesis of functional nanomaterials

“…Without going through a zero-valent state, the precursor compounds can be directly convered into dimers and trimers. Reduction Single-crystals Perfect/truncated cube Pd [208,240], Ag [43,64,241], Au [242,243], Pt [244,245], Cu [246], Rh [247], Fe [248] Concave cube Pd [219] Perfect/truncated octahedron Pd [193,194], Ag [43,64], Au [242,243], Pt [244,245] Perfect/truncated tetrahedron Ag [241],Au [243,249], Pt [45,244] Rectangular bar Pd [186] Multipods Au [250], Pt [244,245,251], Rh [247] Singly twinned Right bipyramid Pd [252], Ag [253] Multiply twinned Decahedron Pd [193], Ag [254], Au [243,249] Icosahedrons Pd [193], Au [249] Five-fold twinned pentagonal rod/wire Pd [255], Ag [256], Au [257], Cu [255] Triangular/hexagonal plate Pd …”

Organic–Inorganic Mesoporous Silica Nanotube Hybrid Anodic Alumina Membranes for Ultrafine Filtration of Noble Metal Nanoparticles

“…They controlled the particle size of Pd NPs within 3.5-7 nm by varying the concentration of the stabilizing surfactant. Niu et al introduced the shape-controlled synthesis of Pd nanocrystals via the seed-mediated method with CTAB, potassium iodide, and ascorbic acid as the surfactant additive and reductant, respectively (Niu et al, 2010). Several types of Pd nanocrystals, such as rhombic dodecahedral, cubic and octahedral have been prepared by manipulating potassium iodide concentration and the reaction temperature.…”