We improve the conversion efficiency of Ag₂S quantum dot (QD)-sensitized TiO₂ nanotube-array electrodes by chemically depositing ZnO recombination barrier layer on plain TiO₂ nanotube-array electrodes. The optical properties, structural properties, compositional analysis, and photoelectrochemistry properties of prepared electrodes have been investigated. It is found that for the prepared electrodes, with increasing the cycles of Ag₂S deposition, the photocurrent density and the conversion efficiency increase. In addition, as compared to the Ag₂S QD-sensitized TiO₂ nanotube-array electrode without the ZnO layers, the conversion efficiency of the electrode with the ZnO layers increases significantly due to the formation of efficient recombination layer between the TiO₂ nanotube array and electrolyte.