Nucleation and Growth of BaFxCl2−xNanorods

Rapid microwave-enhanced hydrothermal synthesis and shape evolution of uniform NaGdF4:Yb, Er (Tm/Ho) nanocrystals with upconversion and paramagnetic properties

An efficient microwave-enhanced hydrothermal synthesis strategy was developed for the rapid synthesis of β-NaGdF4:Ln(3+) (Ln = Yb, Er/Tm/Ho) nanocrystals (NCs) with multicolour upconversion luminescence and paramagnetic properties. It has been found that the uniform β-NaGdF4:Ln(3+) NCs could be rapidly formed within a few minutes at 160 °C and the shape of the NCs can be manipulated from uniform rod-like to spherical just by tuning the initial reactants' concentration. In comparison to conventional hydrothermal routes, a burst homogeneous nucleation and higher growth rate as well as enhanced dimensional homogeneity of the NaGdF4:Ln(3+) was achieved in microwave synthesis. A microwave-heating-based classical crystallization mode and surfactant-assisted anisotropic growth mechanism were proposed for the formation of β-NaGdF4:Ln(3+) NCs.

Controlled synthesis of semiconductor nanostructures in the liquid phase

The microstructure (composition, size and shape etc.) of semiconductor nanocrystals determine the electronic density of states of semiconductor nanomaterials and ultimately determine their optical and electrical properties. Semiconductor nanocrystal advanced structures, such as hybrid nanostructures and nanocrystal superlattices, not only integrate the function of individual nanocrystals, but also brings the materials collective and synchronic properties. How to control the monodispersity, composition and structure of as-prepared semiconductor nanocrystals during their syntheses, as well as their furthermore assembly, has been a hot research area in this decade. This critical review focuses on the development of synthetic and assembly methods (techniques) of semiconductor nanocrystals processed in the liquid phase. Emphasis is on the synthesis methodology, microstructure related properties of semiconductor nanocrystals, and their applications (243 references).

ZnS nano-architectures: photocatalysis, deactivation and regeneration

An "infinite recycling" method for enhancing the durable applications of a ZnS nano-photocatalyst is shown. Based on the finding of thermodynamic stable nanophase of ZnS, we designed a strategy in which the deactivated ZnS nano-photocatalyst could be recovered into its original state. This ZnS photocatalyst can be used repeatedly without being released into environment as nano-waste. The strategy uses material highly efficiently and is environmentally friendly.

Nucleation and growth of CeF(3) and NaCeF(4) nanocrystals

Studying growth: The diffusion-controlled kinetic (DCK) model and the surface chemical thermodynamics (SCT) model have been successfully applied to interpret the nucleation and growth mechanism of CeF(3) (see TEM images) and NaCeF(4) nanocrystals, and may generally give light to the size-control and morphology prediction of rare-earth fluorides at the nanoscale level.Monodisperse CeF(3) and NaCeF(4) nanocrystals have been synthesized by using the liquid-solid-solution (LSS) approach. The nucleation and growth of nanocrystalline CeF(3) and NaCeF(4) were controlled by both kinetics and thermodynamics, which can be investigated by the diffusion-controlled kinetic (DCK) model and surface chemical thermodynamics (SCT) theory. The DCK and SCT models were introduced to explain how the ripening time, reaction temperature, and initial concentrations affected the size transition of CeF(3) and NaCeF(4) nanocrystals in detail. Also, these models are believed to be universal and can be applied to explore the morphology evolution of almost all rare-earth fluoride nanocrystals.