First-principles study on the electronic structure and photocatalytic properties of transition metal(Fe,Co,Ni) and N co-doped graphene-like ZnO monolayer

Abstract

We have systematically investigated the electronic structure, magnetic properties, and photocatalytic properties of transition metal(TM = Fe, Co, Ni) and N codoped ZnO monolayer using density functional theory(DFT). All co-doping ZnO monolayer systems exhibit ferromagnetism. The magnetic moment of the co-doping systems mainly comes from the d orbital of the TM elements and the d-p orbital hybridization between the TM elements and the surrounding non-metal atom. The work functions have been further reduced by TM(Fe, Co, Ni) doping. The band edge positions E_CBM and E_VBM are all higher and lower than the oxidation-reduction potential of water at both pH = 0 and pH = 7, respectively. The absorption spectra have a red shift by TM(Fe, Co, Ni) mono- and co-doped. The E_CBM and E_VBM of Co mono-doped and Co/N codoped systems are closer to the standard redox potentials, which is expected to further improve the catalytic efficiency of the material for water splitting. The results demonstrate that the doped ZnO monolayer system is a promising spin electron device and photocatalytic catalyst for water splitting.