On electronegativity of graphitic carbon nitride

Abstract

The values of electronegativity (n = 101) of graphitic carbon nitride (g-C3N4) found in the literature were calculated as the geometric mean of the Mulliken electronegativities of carbon and nitrogen. They mostly varied in the interval of 4.64-4.77eV but were very different from that of 6.91 eV calculated in this work. In comparison, additional electronegativities of g-C3N4 were calculated from conduction band potentials (E-CB) also found in the literature by means of the Butler and Ginley relationship. The obtained results ranged from 3.79 to 4.62 eV with a median of 4.22 +/- 0.04 eV (n = 98). It was concluded that g-C3N4 was a material too complex to be characterized by a single value of electronegativity and a single value of conduction or valence band (E-VB) potential. The Butler and Ginley relationship, as well as the concept of electronegativity, has not been experimentally verified for g-C3N4 so far, hence, only the direct measurement of E-CB or E-VB is recommended.