Conventional and microwave synthesis of mesoporous calcium titanate nanopowders: a comparative study

Mesoporous calcium titanate nanopowders were synthesized in electric furnace and microwave environments using facile single-source precursor route. Structure-property relations of synthesized products were comprehensively characterized. Phase analysis suggested thermal decomposition mechanism as a primary reason behind formation of crystalline calcium titanate phase. Rietveld refinement suggested that increase in calcination temperature increased the phase quantity, crystallite size, and lattice strain in calcium titanate crystals, whereas lattice parameters of calcium titanate remained close to standard dimensions. Nanopowders synthesized in electric furnace exhibited more weight loss (7%) than one synthesized in microwave. Both molecular and elemental structures supported formation of calcium titanate in synthesized products. Calcined particles were of elongated shape having average length of 7517 and 8617nm for nanopowders synthesized in electric furnace and microwave, respectively. Isotherms confirmed the mesoporous structure of calcined nanopowders consisted of elongated particles having slit-shaped pores. Specific surface area of particles was 20 and 18m(2)g(-1) for calcined nanopowders synthesized in electric furnace and microwave environments, respectively. Furthermore, microwave-synthesized nanopowder was more porous than one synthesized in electric furnace. In addition, mean diameter of capillary pores in microwave-synthesized nanopowder was 25% bigger than one synthesized in electric furnace. In summary, heating environments primarily affected the nanoparticle size distribution, volume% of porosity, and pore size distribution of calcium titanate nanopowders, although their phase, thermal, and molecular structures remained almost identical. [GRAPHICS] .