Critical observations in the research of carbon nitride

Abstract

A critical view on the research of carbon nitride (CNx) with an emphasis on the predicted α- and β-C3N4 phases derived from their Si3N4 analogues is presented. This paper highlights the reasons for the less occurrence of planar nitrogen in both phases which otherwise presumed to be existed as in their silicon nitride counterparts which to date, has not been searched and reported approriately. Also, other hypothetical C3N4 phases including the very recently predicted spinel phase, c-C3N4 are discussed. Further, the recent synthesis of carbon nitrides and their characterisations are briefly reviewed. Finally, an outlook is presented which includes most promising synthesis routes for crystalline carbon nitride. © 2001 Elsevier Science B.V. All rights reserved.