A core-shell structure of Mg@CdS quantum dots (QDs) with ZnS passivation layer deposited on TiO2 mesoporous film, denoted as TiO2/Mg@CdS/ZnS, is fabricated as photoanode for enhancement of quantum dot sensitized solar cells efficiency. High resolution transmission electron microscope images and X-Ray photoelectron spectroscopy analysis confirm the core sell structure of Mg@CdS. Introduction of Mg nanoparticles in the photoanode indicates a rise in photovoltage and photocurrent density by decreasing the charge recombination and increasing the photon capturing ability indicated by photoluminescence and diffuse reflectance spectroscopy, respectively. TiO2/Mg@CdS signifies excellent charge injection and transfer efficiency in photoanode. Moreover, Zinc sulfide is utilized as the passivation layer to inhibit electron recombination between photoanode and electrolyte interface. The achieved power conversation efficiency of the TiO2/Mg@CdS/3ZnS is 7.47% which is significantly higher than TiO2/CdS (2.87%) and TiO2/Mg@CdS (5.37%) photoanodes. Electrochemical impedance spectroscopy implies the higher charge recombination resistance between photoanode and electrolyte interface in solar cell fabricated using TiO2/Mg@CdS/3ZnS photoanode. (C) 2019 Elsevier Ltd. All rights reserved.