Hydrogen as a potential fuel of the future can be produced in a photoelectrochemial water splitting process. Herein, we demonstrate the fabrication of photoelectrochemical electrodes based on SrTiO₃-TiO₂ with a eutectic composition on titanium and conductive glass FTO (fluorine doped tin oxide) substrates by magnetron sputtering. The XRD and SEM/EDS reveal the amorphous nature and homogeneity of the sputtered material. The influence of the layer thickness on the photoactivity was investigated. There were three-layer thicknesses (50, 350, and 750 nm) selected by sputtering for 12, 80 and 220 min for the preparation of photoelectrodes. The photoelectrochemical analysis confirms the photoactivity of the obtained layers under illumination with a xenon lamp (600 mW/cm²). The highest photocurrent density of 11.8 × 10⁻³ mAcm⁻² at 1.2 V vs. SCE was recorded for a layer thickness of 50 nm on titanium as better matching between the Ti work function and the conduction band.