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Core/Shell Heterostructures: Synthesis, Characterization and their Optical
Applications
Sandeep Kumara,a,b M. Thirumal,b Ashok K. Gangulia,c*
a
Department of Chemistry, Indian Institute of Technology, Hauz Khas, New Delhi 110016, India
b
Department of Chemistry, University of Delhi, Delhi 110007, India
c
Institute of Nano Science & Technology, Habitat Centre, Phase X, Sector 64, Mohali, Punjab
160062, India
E-mail: [email protected]
Tunability of electronic and optical properties of semiconductor nanostructures has been an
important subject in nanotechnology.1 Environmental problems such as organic pollutants and toxic water
pollutants produced by some industries are harmful to human health and the general well-being of man.
Semiconductor photocatalysis,2 as a “green” technique, has received much attention as a potential solution
to the worldwide energy shortage and for counteracting environmental degradation. The motivation of the
present research originated from the idea that the coupling of wide band gap semiconductor3 with the
narrow band gap semiconductor (which acts as sensitizer) forms an efficient heterostructures (core/shell)
for the separation of photogenerated charge carriers and makes it a good candidate for visible-light
photocatalysis. Herein, we report the synthesis of core/shell heterostructures using soft chemical method.
The fabricated core/shell system exhibited efficient light harvesting with high photocatalytic and
photoelectrochemical efficiency due to their wide range of light absorption. The spatial electron-hole
separation between the core and shell, greatly enhanced by the type - II band structure offset in these coreshell heterostructures, results in the extremely long exciton lifetime. These core/shell nanorods with
enhanced optical and promising electrical properties hold a good potential to be applied in future
optoelectronic devices such as photoelectrochemical cells, light emitting diodes and photocatalysis.
Figure: Schematic diagram showing separation of photogenerated charge carriers in NaNbO3/CdS
core/shell heterostructures and photocatalytic efficiency
References:
[1] Ashok K Ganguli, Sonalika Vaidya and Aparna Ganguly, Chem. Soc. Rev., 39, 2010, 474-485.
[2] Fan, W., Zhang, Q., and Wang Y., Phys. Chem. Chem. Phys., 2013, 15, 2632-2649
[3] Z. L. Wang, Mater. Sci. Eng., R, 2009, 64, 33