Spectroscopy of π 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 graphitic carbon nitride planes, structural parameters that determine the mechanical properties of the material. The contribution of p electrons from carbon 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 anisotropy, while the density of pi* states from carbon is isotropic and independent of composition. Both observations are consistent with a model of The superstructure of basal planes.