Divalent Fe Atom Coordination in Two-Dimensional Microporous Graphitic Carbon Nitride.

Graphitic Carbon Nitride (g-C3N4) is a rising two-dimensional material possessing intrinsic semiconducting property with unique geometric configuration featuring superimposed heterocyclic sp(2) carbon and nitrogen network, non-planar layer chain structure, and alternating buckling. Inherent porous structure of heptazine based g-C3N4 feature electron rich sp(2) nitrogen which can be exploited as a stable transition metal coordination site. Multiple metal-functionalized g-C3N4 system have been reported for versatile applications, but local coordination as well as its electronic structure variation upon incoming metal species is not well understood. Here we present detailed bond coordination of divalent iron (Fe(2+)) through micropore sites of graphitic carbon nitride, and provide both experimental and computational evidences supporting aforementioned proposition. In addition, the utilization of electronic structure variation is demonstrated through comparative photocatalytic activities of pristine and Fe-g-C3N4.