Solar Energy Materials and Solar Cells

We report on a controllable growth of single phase Cu2O modified TiO2 nanotube arrays heterojunction with highly enhanced visible light photodegradation of methyl orange in our present work. Various amounts of p-type Cu2O on n-type TiO2 nanotube arrays surfaces were deposited by the DC reactive magnetron sputtering. A serious of characterizations were applied to testify that the slightly loaded p-n heterojunction showed the better ability. The improved absorption edge in visible region was observed to extend to over 700 nm by diffuse reflection. PL spectrum results revaled that Cu2O-TiO2 junction has largely improved the separation of photogenerated electrons and holes. Consequently, the heterojunction photoelectodes exhibited a highly superior photo-degradation of methyl orange with >90% degradation under visible light irradiation for 1.5h. These findings provide us to a versatile method to further design high photoelectric response Cu2O-TiO2 heterojunction with independent visible light absorption layer, separation and transport layer for photo-induced carriers.