Nanoparticle-catalyzed clock reaction

Pande, Surojit, Jana, Subhra, Basu, Soumen, Sinha, Arun Kumar, Datta, Ayan and Pal, Tarasankar (2008) Nanoparticle-catalyzed clock reaction. Journal of Physical Chemistry C, 112 10: 3619-3626. doi:10.1021/jp7106999


Author Pande, Surojit
Jana, Subhra
Basu, Soumen
Sinha, Arun Kumar
Datta, Ayan
Pal, Tarasankar
Title Nanoparticle-catalyzed clock reaction
Journal name Journal of Physical Chemistry C   Check publisher's open access policy
ISSN 1932-7447
1932-7455
Publication date 2008-03-13
Sub-type Article (original research)
DOI 10.1021/jp7106999
Volume 112
Issue 10
Start page 3619
End page 3626
Total pages 8
Place of publication Washington, DC, U.S.A.
Publisher American Chemical Society
Language eng
Subject 0303 Macromolecular and Materials Chemistry
1007 Nanotechnology
Formatted abstract
Bulk Cu2O or cuprite is the only stable copper(I) compound present in plentiful amount in earth's crust. It is a challenging job to take bulk Cu2O to a nanoregime and to stabilize it in solution. No wonder that Cu2O in its nanoregime would act as a photocatalyst. We report a new synthetic protocol for the first time to obtain monodispersed, stable, exclusively cubic Cu2O nanoparticles in surfactant-free condition and its catalytic action for methylene blue (MB)−hydrazine reaction in aqueous medium. The blue color of the dye, MB, faded away upon the addition of hydrazine, producing colorless leuco methylene blue (LMB) indicating the progress of the redox reaction. The rate of this redox reaction has been found to be enhanced in the presence of the nanocatalyst, Cu2O. The success of the reaction demonstrates a simple ‘clock reaction'. An oscillation between a blue MB color and colorless solution due to formation of LMB is observed on periodic shaking. This oscillation continues for over 15 cycles. Studies on the effect of bulk Cu2O and nanoparticles of CuO and Cu(0) have not been successful for demonstration of the ‘clock reaction'. Thus, the importance of Cu2O nanoparticles in the clock reaction is established beyond doubt. The Cu2O nanoparticles were characterized by different physical methods. TEM studies authenticate the cube shaped monodispersed particles. The electrochemical studies indicate that nano-Cu2O shows a couple of redox peaks which correspond to the redox Cu(II)/Cu(I) system. Kinetic studies authenticate a first-order reaction mechanism. Further, quantum chemical calculations reveal that the nanoparticles reduce the activation energy by 17 kcal/mol, thereby making the reaction 2.4 × 107 times faster compared to the gas phase.
© 2008 American Chemical Society
Keyword Nano particles
Copper
Q-Index Code C1
Q-Index Status Provisional Code

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Centre for Nanotechnology and Biomaterials Publications
 
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