Atomic Cu adsorption on defect-free SrTiO3(0Â 0Â 1) surface

► Cu plays as an electron trapping center on SrTiO3(0 0 1) surface. ► Cu mediates charge transfer from electronically excited SrTiO3 to target species. ► Cu can effectively separate photogenerated electron-hole pairs. ► Cu can improve the photocatalytic efficiency of SrTiO3.