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

Abstract Nanostructured thin films of pristine Fe 2 O 3 , Tidoped Fe 2 O 3 , Cu 2 O, and Fe 2 O 3 /Cu 2 O, and Ti-doped Fe 2 O 3 /Cu 2 O heterojunction were deposited on tin-doped indium oxide (Sn:In 2 O 3 ) 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-Fe 2 O 3 /Cu 2 O 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 Fe 2 O 3 , Ti-Fe 2 O 3 , Cu 2 O, Fe 2 O 3 /Cu 2 O, and Ti-Fe 2 O 3 /Cu 2 O 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/cm 2 at 0.95 V/SCE was exhibited by 454 nm thick Ti-Fe 2 O 3 /Cu 2 O 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-Fe 2 O 3 /Cu 2 O interface.