In the present work, to build a water splitting system using only a neutral electrolyte solution and light source, we investigated the photoelectrochemical properties and interface resistances of an IrO2-coated TiO2 photoanode in Z-scheme configuration. The photoelectrochemical cell was connected to the perovskite solar cell with to realize the system with no need for an external electrical bias. Photoanodes with IrO2 were found to support hole transport and to reduce the overpotential, therefore increasing the current density of the system consisting of photoelectrochemical cells. A maximum solar-to-hydrogen efficiency of 8.2% was achieved in a neutral electrolyte.