The electronic structure modification and photocatalytic ability improvement of titanium dioxide doped with silver and copper atoms

Abstract

This research employed density functional theory (DFT) calculations to investigate the electronic structure, band characteristics, and bonding properties of pure titanium dioxide (TiO2) and its silver (Ag)- and copper (Cu)-doped counterparts. The potential of these materials for photocatalytic water splitting to produce hydrogen was assessed. The calculated band gaps were 3.18 eV, 2.3 eV, and 2.1 eV for TiO2, Ag-TiO2, and Cu-TiO2, respectively. Crucially, localized impurity states appeared within the band gap of the doped semiconductors. For Ag-TiO2, the conduction band edge (-0.73 eV) and valence band edge (1.53 eV) were favorably positioned relative to the redox potentials for water splitting, suggesting promising photocatalytic activity.