Doped TiO2 slabs for water splitting: a DFT study

Abstract

Abstract The realization of water splitting at a commercial scale is one of the major obstacles to the development of a viable and long-term hydrogen economy. In this regard 3d-transition metals (TMs) doped anatase TiO2 slabs are investigated to understand the role of magnetism in water splitting using density functional theory (DFT). The structural stability of various 3d-TMs (V, Cr, Mn, Fe, Co, Ni, and Cu) doped in TiO2 ultrathin films have been investigated. The electronic band structures show that the doping of 3d-TMs makes the bandgap of TiO2 narrow which leads to the improvement of photo-reactivity as well as maintains the strong redox potential. The large magnetic moment of Fe- and Mn-doped slabs indicates that high charge transfer to water molecules with low adsorption energy. The results demonstrate that V, Fe, and Co doping makes the slabs ferromagnetic (FM), whereas Cr, Mn, Ni, and Cu doping makes the slabs non-magnetic. The water molecule is placed on each FM slab and their splitting behavior has been analyzed thoroughly. It was concluded that magnetism does not affect water splitting.