Computational study on the half-metallicity in transition metal-oxide-incorporated 2D g-C 3N 4 nanosheets

In this study, based on the first-principles calculations, we systematically investigated the electronic and magnetic properties of the transition metal-oxide-incorporated 2D g-C 3N 4 nanosheet (labeled C 3N 4- TM-O, TM= Sc-Mn). The results suggest that the TM-O binds to g-C 3N 4 nanosheets strongly for all systems. We found that the 2D C 3N 4-TM-O framework is ferromagnetic for TM= Sc, Ti, V, Cr, while it is antiferromagnetic for TM= Mn. All the ferromagnetic systems exhibit the half-metallic property. Furthermore, Monte Carlo simulations based on the Heisenberg model suggest that the Curie temperatures ( T c) of the C 3N 4-TM-O (TM= Sc, Ti, V, Cr) framework are 169 K, 68 K, 203 K, and 190 K, respectively. Based on Bader charge analysis, we found that the origin of the half-metallicity at Fermi energy can be partially attributed to the transfer of electrons from TM atoms to the g-C 3N 4 nanosheet. In addition, we found that not only electrons but also holes can induce half-metallicity for 2D g-C 3N 4 nanosheets, which may help to understand the origin of half-metallicity for graphitic carbon nitride.