Au adsorption and Au-mediated charge transfer on the SrO-termination of SrTiO3 (0 0 1) surface

Abstract Atomic Au adsorption on the SrO-termination of SrTiO 3 (0 0 1) surface has been studied by means of the first-principles calculations based on the density functional theory (DFT). It indicates that charge polarization dominantly contributes to the bonding between Au and SrO-termination. Interfacial charge transfer induces dipole moment and changes work function. The mediating role Au played in charge transfer from electron-doped SrTiO 3 :Nb to NO has been simulated. Charge transfer from SrTiO 3 :Nb to Au is ascertained indicating that Au plays as an electron trapping center. SrO-termination has weak activity to NO while the molecule can be strongly adsorbed on negatively charged Au atom. It has been represented that Au mediates the charge transfer from SrTiO 3 :Nb to NO. Antibonding orbital (π 2p *) of NO accommodates the charge and thus molecular bond is weakened (activated). Fukui functions demonstrate the role Au played in transiting the charge transfer from electronically excited SrTiO 3 to target species. Evidence that metal deposited on photocatalyst surface effectively separates the electron–hole pairs and improves the photocatalytic activity is presented in the current work.