Shape Control of Semiconductor and Metal Oxide Nanocrystals through Nonhydrolytic Colloidal Routes

Abstract

Inorganic nanocrystals with tailored geometries exhibit unique shape-dependent phenomena and subsequent utilization of them as building blocks for the fabrication of nanodevices is of significant interest. Herein, we review the recent developments in the shape control of colloidal nanocrystals with a focus on the scientifically and technologically important semiconductor and metal oxide nanocrystals obtained by nonhydrolytic synthetic methods. Many structurally unprecedented motifs have been discovered including polyhedrons, rods and wires, plates and prisms, and other advanced shapes such as branched rods, stars, inorganic dendrites, and dumbbells. The currently proposed shape-guiding mechanisms are presented and the important pioneering studies on the assembly of shape-controlled nanocrystals into ordered superlattices and the fabrication of prototype advanced nanodevices are discussed.

Flower-like tungsten oxide particles: Synthesis, characterization and dimethyl methylphosphonate sensing properties

“…Morphology and microstructure of as-prepared WO 3 Fig. 1a shows the overall morphology of as-prepared WO 3 . Clearly, it has a flower-like morphology which consists of a large number of nanoflakes.…”

“…Syntheses of inorganic materials with controlled morphologies, sizes, and architectures have attracted intensive interests since these parameters play a key role in determining their electrical, optical and sensing properties [1][2][3]. An ideal sensor requires high sensitivity, short response and recovery time as well as high selectivity.…”

Nonaqueous Sol–Gel Routes to Metal Oxide Nanoparticles

“…7,8 Nonaqueous processes can be divided into two general methodologies, namely, surfactant-and solvent-controlled preparation routes. This Account provides a short over-view of these two strategies, highlighting advantages and limitations as well as elaborating some general reaction principles based on selected examples from the literature.…”

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

“…[40] Reagent concentration, reaction temperature and residence time are of the most critical factors in controlling the size, crystallinity, and shape of the resultant nanoparticles (Figure 3b). [41] Following the primary nucleation of nanoparticles, critical growth parameters such as surface energy and growth rate along with the factors mentioned determine the final shape of the resultant nanoparticles during the crystal growth. [42] Presence of a homogenous reaction environment followed by ultrafast mixing along with controlling the mixing time of reagents can lead to the fabrication of nanoparticles desired properties.…”

“…[206] The critical factors effecting the preparation of nanomaterials are reagent concentration, reaction temperature, and residence time for the size of nanoparticles, and crystalline surfaces for their shape. [41] Since MF systems provide a potential controlling ability over reaction time, reaction temperature, and concentration of reagents, particles with better narrow size distribution can be achieved by quenching the reaction whenever the desired size of the NPs is reached. [207] …”