Informal DQMP seminar

Carte non disponible

Day / Time
Date(s) - 29/05/2015
11 h 00 min - 12 h 30 min

Category


Salle MaNEP, Ecole de physique

PARASURAMAN SELVAM
National Centre for Catalysis Research and Department of Chemistry,
Indian Institute of Technology – Madras, Chennai 600036, India
Also at: New Industry Creation Hatchery Center, Tohoku University, Sendai 980 8579, Japan
and, School of Science and Health, University of Western Sydney, Penrith, NSW 275, Australia

 

Size- and Shape-controlled Nanostructured Materials and Their Applications
Metal nanoparticles possess unique properties and are more dynamic than the
corresponding bulk materials while they are not quite the same as individual atoms or molecules.
Such metal nanoparticles hold higher surface-to-volume ratios than the bulk counterparts. In
paticular the noble metal nanoparticles/clusters are useful in catalysis owing to the large fraction of
active atoms on the surface. Furthermore, shape- and size-controlled gold nanoparticles show
distinct characteristics as they have different fractions of atoms exposed on the surface. Different
sizes of nanoparticles with narrow size distributions were achieved by suitably tuning the preparation
parameters. In this way, uniform-sized noble metal clusters, such as gold, platinum, palladium, etc.
having both isotropic and anisotropic shapes can be achieved in a single-step method by using
appropriate reducing and capping agents as well as by tuning the preparation parameters. Likewise,
the discovery of periodic nanoporous materials including silica, alumina, carbon and several
oxides, viz., silica, alumina, titania, iron oxide, zirconia, ceria, etc. with precise and easily controllable
pore shapes and sizes has created new avenues in advanced materials research. The unique
flexibility in terms of synthetic conditions, pore size tuning, high surface area, large internal hydroxyl
groups, etc. has opened-up new opportunities. On the other hand, the preparation of high quality
materials with designed pore structures is of paramount importance, and in designing such materials,
several characteristics such as modification of framework structure, pore size, shape and
interconnectivity, etc. must be addressed. In this presentation, a brief account of the recent
development on the subject will be discussed.

 

Réalisation : Sur Mesure concept