Preparation and Optical Properties of CdS Nanocrystals Prepared by a Mechanical Alloying Process

Abstract

CdS nanocrystals have been successfully synthesized by a mechanical alloying process. The X-ray diffraction (XRD) pattern shows that the major phase of the product was wurtzite CdS compound after mechanical alloying of the elemental powders for 60 min. All the diffraction peaks from the elemental Cd and S powders disappeared completely in the XRD patterns of as-milled CdS nanocrystals ball milled for more than 10 h. High-resolution transmission electron microscopy (HRTEM) images confirmed the wurtzite structure of as-milled CdS nanocrystals. The as-milled CdS nanocrystals were subsequently capped with trioctylphosphine oxide/trioctylphosphine/nitric acid (TOPO/TOP/NA), which leads to the formation of yellow dispersion solution. The size of capped CdS nanocrystals ranges from 1.6 to 6.2 nm. The capped CdS nanocrystals show similar optical properties to those CdS nanocrystals prepared by the wet chemical process, the absorption peaks for the capped CdS nanocrystals locate within the range of 345 to 380 nm.

Electrospun nanofibers of TiO2/CdS heteroarchitectures with enhanced photocatalytic activity by visible light

“…Moreover, the absorption edges also show a slight redshift. This result could be attributed to increased particle size and broadened size distribution of CdS nanoparticles [27,28]. Above results indicate that the TiO 2 /CdS heteroarchitectures can absorb in UV as well as in visible region of the solar light.…”

Growth Mechanism and Optical Properties Determination of CdS Nanostructures

“…Apart from wet chemical synthesis, discussed above, for solid phase synthesis of CdS nanocrystals a mechanical alloying process has been adopted to avoid toxicity of metal organic precursors and high temperature, used in solution phase synthesis . However, after all, the wet chemical synthetic routes have their own merits because a number of physical and chemical parameters can be manipulated to tailor the nanostructured materials of desired shape, size, and distribution which are highly desired for optical and electronic applications, and therefore understanding the growth mechanism in solution phase synthesis is a great challenge before materials chemists.…”

Preparation of uncapped CdSe1−xSx semiconducting nanocrystals by mechanical alloying

“…Both the chemical composition and varied lattice spacing may contribute to the modulation of the nanocrystal's bandgap energies. The microstructures of as-milled CdSe and CdS nanocrystals have been discussed in detail in the literature, 39,40 therefore, their microstructure features will not be repeated in this paper. Figure 3 shows two HRTEM images of as-milled CdSe 0.5 S 0.5 nanocrystals dispersed in ethanol by sonication.…”

“…[36][37][38] This approach is simple and generally run in tens of grams scale and can be easily scalable. Indeed, mechanical alloying has been applied successfully to prepare semiconducting CdS, 39 CdSe, 40 CdTe, 41 and some other nanocrystals. 38,42,43 In this contribution, we show for the first time that simple mechanical alloying (MA) can be used to prepare uncapped ternary CdSe 1Àx S x nanocrystals through the entire composition range.…”