Nanostructured SrTiO_3 thin films sensitized by Cu_2O for photoelectrochemical hydrogen generation

摘要

We prepared nanostructured thin films of pristine SrTiO_3, Cu_2O and SrTiO_3/Cu_2O hetero-junction with varying the thickness of Cu_2O. SrTiO_3 and Cu_2O thin films were deposited on ITO (Sn:In_2O_3) glass substrate using sol-gel spin-coating technique and spray pyrolysis method respectively. Samples were characterized using XRD (X-ray diffractometry), SEM (Scanning electron microscopy), and UV-Visible absorption spectroscopy. Nanostructured thin films of pristine SrTiO_3, Cu_2O and SrTiO_3/Cu_2O heterojunction systems were used as photoelectrode in the Photoelectrochemical (PEC) cell for water splitting reaction. Maximum photocurrent density value of 2.44 mA cm~(-2) at 0.95 V/SCE were observed for SrTiO_3/Cu_2O heterojunction photoelectrode with 454 nm thickness, which was approximately 34 times higher than pristine SrTiO_3 thin film. Increased photocurrent density observed for the heterojunction can be attributed to the improved conductivity and better separation of the photogenerated charge carriers at the SrTiO_3/Cu_2O interface.