Kusuma Manjunath and Chandrappa G. Thimmanna Pages 145 - 155 ( 11 )
Background: CaTiO3, being a member of perovskite family, has a broad range of properties and can be used in different applications such as biomedical, photocatalytic and communication equipment operating at microwave frequencies. CaTiO3 is one of the important components for the immobilization of high level radioactive wastes and is extensively used in electronic ceramic materials. CaTiO3 has been investigated for biocompatible and luminescent material and exhibits a combination of high permittivity and modest dielectric loss. CaTiO3 could be of great usefulness for the development of integrated circuits in microelectronic industry in the future.
Method: Perovskite CaTiO3 has been synthesized via facile solution combustion synthesis using titanium peroxo complex.
Results: The X-ray diffraction pattern revealed the pure perovskite structure. Microstructures with porous morphology were observed using a scanning electron microscopy. Transmission electron microscopy images showed a uniform particle size distribution with average particle sizes varying in the range of 30-70 nm. The surface area ~30.89 m2/g was measured by BET method. The band gap of 3.54 eV was calculated using the diffuse reflectance spectrum of CaTiO3. The photoluminescence spectra of CaTiO3 powder exhibited a violet shift and blue shift at 441 nm and 483 nm with an excitation wavelength at 351 nm. An investigation on frequency dependence of dielectric constant (έ) and tangent loss (tan δ) showed a dispersive behavior at low frequencies. The photocatalytic degradation of methylene blue (MB) using CaTiO3 as photocatalyst showed 98 % of decolourisation only in the presence of solar radiation.
Conclusion: The prepared CaTiO3 reveals good properties and application which act as a good photocatalyst in the presence of natural sunlight. This material can act as a noble candidate for next generation.
Nano calcium titanate, perovskite, combustion synthesis, dielectric constant, photoluminescence, photocatalyst, methylene blue.
Department of Chemistry, Central College Campus, Bangalore University, Bangalore-560001, India.