Combustion synthesis, characterization and Raman studies of ZnO nanopowders

Reddy, Jagannatha A and Kokila, MK and Nagabhushana, H and Rao, JL and Shivakumara, C and Nagabhushana, BM and Chakradhar, RPS (2011) Combustion synthesis, characterization and Raman studies of ZnO nanopowders. In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 81 (1). pp. 53-58.

PDF Combustion.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

Spherical shaped ZnO nanopowders (14-50 nm) were synthesized by a low temperature solution combustion method in a short time <5 min. Rietveld analysis show that ZnO has hexagonal wurtzite structure with lattice constants a = 3.2511(1) angstrom, c = 5.2076(2) angstrom, unit cell volume (V) = 47.66(5) (angstrom)(3) and belongs to space group P63mc. SEM micrographs reveal that the particles are spherical in shape and the powders contained several voids and pores. TEM results also confirm spherical shape, with average particle size of 14-50 nm. The values are consistent with the grain sizes measured from Scherrer's method and Williamson-Hall (W-H) plots. A broad UV-vis absorption spectrum was observed at similar to 375 nm which is a characteristic band for the wurtzite hexagonal pure ZnO. The optical energy band gap of 3.24 eV was observed for nanopowder which is slightly lower than that of the bulk ZnO (3.37 eV). The observed Raman peaks at 438 and 588 cm(-1) were attributed to the E(2) (high) and E(1) (LO) modes respectively. The broad band at 564 cm(-1) is due to disorder-activated Raman scattering for the A(1) mode. These bands are associated with the first-order Raman active modes of the ZnO phase. The weak bands observed in the range 750-1000 cm(-1) are due to small defects. (C) 2011 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	ZnO;Combustion synthesis;XRD;SEM;TEM;FTIR;UV-vis;Raman spectroscopy
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	21 Dec 2011 09:08
Last Modified:	21 Dec 2011 09:08
URI:	http://eprints.iisc.ac.in/id/eprint/42534

Actions (login required)

View Item