Synthesis and adsorption ability of nanoparticles of perovskite oxynitride LaTiO₂N

Abstract

We synthesized a perovskite-type oxynitride, LaTiO₂N, by nitridation of the oxide precursor under NH₃ atmosphere at low temperature and flow rate. We successfully synthesized LaTiO₂N at 1023 K (750°C) under flowing NH₃ gas at a rate of 18 dm³/h using a handmade rotary furnace form the amorphous oxide precursor prepared by a sol-gel technique-polymerizable complex method. The average particle size of the LaTiO₂N sample prepared at 1023 K (750°C) (LTON-750) was smaller than for the LaTiO₂N sample prepared by a conventional solid-state reaction method at 1223 K (950°C) (LTON-SS). The smallest particle size of LTON-750 was estimated at 20-30 nm. The BET surface area of LTON-750, calculated from the N₂ adsorption isotherm, was 35.0 m²/g. This is approximately 2 times greater than that of LTON-SS. Furthermore, LTON-750 and LTON-SS demonstrated the ability to adsorb H₂ at 77 K.