Nanostructured Ti-Fe2O3/Cu2O heterojunction photoelectrode for efficient hydrogen production

Nanostructured thin films of pristine Fe2O3, Tidoped Fe2O3, Cu2O, and Fe2O3/Cu2O, and Ti-doped Fe2O3/Cu2O heterojunction were deposited on tin-doped indium oxide (Sn:In2O3) glass substrate using spray pyrolysis method. Ti doping is done to improve photoelectric conversion efficiency and electrical conductivity of hematite thin films. Further enhanced photocurrent is achieved for Ti-Fe2O3/Cu2O heterojunction electrodes. All samples were characterized using X-ray diffractometry, scanning electron microscopy, atomic force microscopy, and UV-Vis spectrometry. Photoelectrochemical properties were also investigated in a three-electrode cell system. UV-Vis absorption spectrum for pristine Fe2O3, Ti-Fe2O3, Cu2O, Fe2O3/Cu2O, and Ti-Fe2O3/Cu2O heterojunction thin films exhibited absorption in visible region. Nanostructured thin films as prepared were used as photoelectrode in the photoelectrochemical cell for water splitting reaction. Maximum photocurrent density of 2.60 mA/cm2 at 0.95 V/SCE was exhibited by 454 nm thick Ti-Fe2O3/Cu2O heterojunction photoelectrode. Increased photocurrent density and enhanced incident photon-to-electron conversion efficiency, offered by the heterojunction thin films may be attributed to improved conductivity and efficient separation of the photogenerated charge carriers at the Ti-Fe2O3/Cu2O interface.