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Posted: Jan 09, 2013
Rational design of hybrid nanostructures for advanced photocatalysis
(Nanowerk News) The modern advances in well controlled fabrication of metal nanoparticles and their composites have assisted material scientists in the design and effi cient utlilization of desired catalysts, as is evidenced by explosive growth in the nanocatalysis field.
In it, the authors describe the dependence of the size, shape, exposed crystal planes of the metal nanoparticle, composition of bimetallic nanoparticle, metal-semiconductor hybrid nanostructures and metal oxide composites on the selectivity and yield of the product in different chemical transformations.
Nanocatalysis has been a growing field over the past few decades with significant developments in understanding the surface properties of nanocatalysts.
With recent advances in synthetic methods, size, shape and composition of the nanoparticles can be controlled in a well defined manner which facilitates achieving selective reaction products in multipath reactions.
Nanoparticles with specific exposed crystal facets can have different reactivity than other facets for reaction intermediates, which favours selective pathways during the course of reaction. Heterogeneous catalysts have been studied extensively; nano-sized metal particles are absorbed on mesoporus supports, facilitating access to the large surface area of the nanoparticles and hence exposure of more catalytic sites.
Photocatalysis is attractive area of catalysis, in which photoinduced charge carriers are used for a variety of catalytic applications.
More interestingly, clean and renewable liquid fuels energy sources such as hydrogen and methyl alcohol can be generated using photocatalysts through water splitting and CO2 reduction, respectively.
In their review, the authors discuss selective examples of chemical reaction catalysed by metal, bimetallic nanoparticles, metal oxide nanoparticles and hybrid nanostructures. The influence of the morphology and composition of the nanocatalyst on the catalytic activity is highlighted for different catalysts.
A new generation of photocatalysts composed of multi-component hybrid nanostructure is emphasized for H2 generation in water splitting reaction as well as CO oxidation.
The shape selective catalytic activities of metal oxide and transition metal loaded oxide nanoparticle are explained for organic conversion and biological application.