Spectroscopy of pi bonding in hard graphitic carbon nitride films: Superstructure of basal planes and hardening mechanisms

X-ray-absorption near-edge spectroscopy (XANES or NEXAFS) has been used to obtain information on the orientation, corrugation, and cross-linking of gr aphitic carbon nitride planes, structural parameters that determine the mec hanical properties of the material. The contribution of p electrons from ca rbon and nitrogen atoms to rr bonding in graphitic carbon nitride has been studied with elemental and angular sensitivity by XANES. The density of pi* states from nitrogen is composition dependent and presents angular anisotr opy, while the density of pi* states from carbon is isotropic and independe nt of composition. Both observations are consistent with a model of The sup erstructure of basal planes.