Tetragonal zirconia quantum dots in silica matrix prepared by a modified sol–gel protocol
- 48 Downloads
Tetragonal zirconia quantum dots (t-ZrO2 QDs) in silica matrix with different compositions (x)ZrO2–(100 − x)SiO2 were fabricated by a modified sol–gel protocol. Acetylacetone was added as a chelating agent to zirconium propoxide to avoid precipitation. The powders as well as thin films were given thermal treatment at 650, 875 and 1100 °C for 4 h. The silica matrix remained amorphous after thermal treatment and acted as an inert support for zirconia quantum dots. The tetragonal zirconia embedded in silica matrix transformed into monoclinic form due to thermal treatment ≥ 1100 °C. The stability of tetragonal phase of zirconia is found to enhance with increase in silica content. A homogenous dispersion of t-ZrO2 QDs in silica matrix was indicated by the mapping of Zr, Si and O elements obtained from scanning electron microscope with energy dispersive X-ray analyser. The transmission electron images confirmed the formation of tetragonal zirconia quantum dots embedded in silica. The optical band gap of zirconia QDs (3.65–5.58 eV) was found to increase with increase in zirconia content in silica. The red shift of PL emission has been exhibited with increase in zirconia content in silica.
Authors gratefully acknowledge University Grants Commission, New Delhi, Govt. of India, for financial assistance in the form of major research project (File no. 42–803/2013(SR) dated 25.03.2013).
- 1.C.J. Brinker, G.W. Scherrer, S.-G. Science, The Physics and Chemistry of Sol–Gel Processing (Academic Press, San Diego, 1990), pp. 1–18Google Scholar
- 4.T. Lopez, M. Asomoza, L. Razo, R. Gomez, Study of the formation of silicoaluminates by the sol-gel method by means IR, DTA and TGA, J. Non-Cryst. Solids 108, 45–48 (1989)Google Scholar
- 6.C. Sanchez, J. Livage, Sol-gel chemistry from metal alkoxide precursors. New J. Chem. 4, 513–521 (1990)Google Scholar
- 8.Z.A. Omran, Crystal structure, surface acidity, surface area, catalytic activity and electrical conductivity behaviour of SiO2–ZrO2 system. Commun. Fac. Scit. Univ. Ank. Ser. C 40, 31–44 (1994)Google Scholar
- 18.Q. Ge, Qinwen, Synthesis and characterization of mesoporous zirconia nanocomposite using self-assembled block copolymer template. Graduate Theses and Dissertations. 12616 (2012)Google Scholar
- 24.S. Surbhi, S. Kumar, Thermal evolution of mixed oxides of zirconia-silica prepared by sol-gel route, in Physics of semiconductor devices, (Environmental Science and Engineering, Springer International Publishing, Switzerland, 2014), pp. 749–751Google Scholar
- 39.J. Coates, Interpretation of infrared spectra, a practical approach, in Encyclopedia of Analytical Chemistry, ed. by R.A. Meyers (Wiley, Chichester, 2000), pp. 10815–10837Google Scholar
- 45.I. Vaizoğullar, A. Balci, M. Uğurlu, Synthesis of ZrO2 and ZrO2/SiO2 particles and photocatalytic degradation of methylene blue. Indian J. Chem. 54A, 1434–1439 (2015)Google Scholar
- 46.A. K. Singh, U.T. Nakate, Microwave synthesis, characterization, and photoluminescence properties of nanocrystalline zirconia. Sci. World J. 2014, Article ID. 349457 (2014)Google Scholar