Low-temperature synthesis and rational design of nitrides and oxynitrides for novel functional material development

Nitrides and oxynitrides exhibit great potential for novel material development, since their electronic structures can be controlled by tuning the amounts of air-abundant nitrogen and oxygen elements therein. However, the above control methods still need to be developed, and the crystal and electronic structures of the produced nitrides/oxynitrides need to be understood. Herein, I summarize the recent progress in nitride and oxynitride synthesis, highlighting novel low-temperature nitridation of oxides by molten NaNH2, and attempt to rationalize the crystal and electronic structures of nitride and oxynitrides. Moreover, I describe how the catalytic activity of manganese oxynitrides in the oxygen reduction reaction can be enhanced by tuning their nitrogen content and thus their electronic structures. (C)2017 The Ceramic Society of Japan. All rights reserved.