Photoelectrochemical Properties of α-Fe2O3:Sn/CuFe2O4 Composite Nanorod Arrays as Photoanodes

α-Fe2O3:Sn/CuFe2O4 composite electrodes are prepared to improve the photoelectrochemical properties via a simple solution/heat treatment performed for α-Fe2O3:Sn nanorod electrodes on fluoride tin oxide glass substrates. Based on the characterizations and analysis of X-ray diffraction and field emission scanning electron microscopy with energy-dispersive spectroscopy, it was found that a crystalline CuFe2O4 phase for composite electrodes was formed after treatment. Compared to the bare α-Fe2O3:Sn electrode, significantly enhanced photocurrent density for α-Fe2O3:Sn/CuFe2O4 composite electrodes was also found in the photoelectrochemical measurements because CuFe2O4 has conduction and valence band edges shifted from those of Fe2O3, which allows for the efficient separation of electron-hole pairs at the α-Fe2O3:Sn/CuFe2O4 interface.