Present study investigates the system of small and large band gap materials for their use in Photoelectrochemical splitting of water. Electrodeposited Zr doped hematite (α-Fe2O3) films were subjected to ZnO quantum dots sensitization for 24, 48, and 72 hours which later on characterized for optical, structural, morphological and photoelectrochemical properties. These sensitized films, when used as photoelectrode in PEC cell, showed a significant increase in the photocurrent density as compared to unsensitized films. This may be attributed to reduction in carrier recombination rate along with photocatalytic effect of ZnO. The enhanced photo response has also been supported by increased negative value of flat band potential from -0.29V/SCE for unsensitized film to -0.8V/SCE for ZnO QDs sensitized hematite film, as examined by Mott-Schottky curve. In the present system, small band gap hematite has been chosen as a main solar energy absorber, while wide band gap ZnO QDs decorated over it, as an efficient electron transport across the interface by reducing charge carrier recombination rate.