பொருள் அறிவியல் & பொறியியல் இதழ்

Ionic Liquid Green Synthesis of CeO2 Nanorods and Nano-Cubes: Investigation of the Shape Dependent on Catalytic Performance

Abstract

Xianfang Zhu

We first introduce a novel nanosize concept and a novel “nanotime” concept along with reviewing a series of novel phenomena and novel techniques related to nanosize effect and ultrafast process, which were recently discovered in our lab or were reported in literature. In these concepts, for the first time we are able to account for the non equilibrium, amorphous-like, and nonlinear nature of the current nanoscience and nanotechnology. In particular, we demonstrate that the structure instabilities of materials occur when a material system is limited to a space within a scale that is comparable to atomic distance. Such a nanosize effect is crucially dependent only on the nanosize but also on nanoshape or nanocurvature (including positive nanocurvature and negative nanocurvature). We also demonstrate that the structure instabilities of materials occur as well when the exchange of external energy with materials is limited to a time within a scale that is comparable to atomic vibration period. Such a “nanotime” effect can give rise to either soft mode or instability of atomic vibration in a condensed matter. The new concepts are very meaningful for control over fabrication and energetic beam processing of low dimensional nanostructures and nanodevices, especially for several potential applications related to nanoparticles, nanocavities, carbon nanotubes�?and nanowires.

The new concepts have similarly important implications for chemistry, biology, and medicine as demonstrated by immerging new findings about nanocavities and nanolaser irradiation. In particular, in biology and medicine, there are widespread research interests either in using nanocavity (shell-core) structure to design and build biology composites, biosensors, drug deliverer, and protein structures or in nano surgery via ultrafast nanolaser processing, both being operative at the molecular level dealing with the concepts put forward herein.