Novel TaPO5-xN2x/3 oxynitrides
Résumé
A series of novel nitrided tantalophosphates has been prepared by nitridation of X-ray amorphous TaPO5 precursors under ammonia flow. By varying the nitridation temperature, amorphous TaPO5-xN2x/3 (1.6 < x < 4.1) oxynitrides were obtained with different nitrogen contents (N wt.% = 5-15). The most relevant features of this oxynitride series are as follow: (i) specific surface areas higher than 150 m2.g−1, (ii) yellow to orange colors depending on nitrogen contents and (iii) formation of a solid solution with variable nitrogen and oxygen contents. The precursors and corresponding oxynitrides have been characterized by several techniques including X-ray diffraction, oxygen/nitrogen elemental analyses, BET analysis, UV-vis spectrophotometry, thermal analysis, SEM, DRIFT and NMR analyses.