Substrate-dependent photocatalytic properties of electrochemical deposited Cu₂O heterojunction

Riza Ariyani Nur Khasanah^1*

¹Applied Physics, Tunghai University, Taichung, Taiwan

* Presenter:Riza Ariyani Nur Khasanah, email:riza.ariyani.n@mail.ugm.ac.id

Cu2O is a promising material for photocatalysis because of its absorption ability in the ultraviolet (UV)-visible light range. Cu₂O deposited on conductive Ti and fluorine-doped tin oxide (FTO) substrates behaves as a photocathode. Cu₂O deposited on an n-type semiconductor such as TiO₂ nanotube arrays (TNA) behaves as a photoanode and has demonstrated better photocatalytic activity than that of TNA. The substrate-dependent photocatalytic property of Cu₂O heterojunctions remain unclear. In this work, the photocatalytic properties of a Cu₂O/TNA junction as a photoanode and of Cu₂O/Ti and Cu₂O/FTO junctions as photocathodes without bias were systematically studied to understand their performance. The Cu₂O/TNA photoanode exhibited greater photocurrent spectral responses, which obviously outperformed the Cu₂O/Ti and Cu₂O/FTO photocathodes. The photoanodic/photocathodic properties of those junctions were depicted in their energy diagrams. Time-resolved photoluminescence indicated that no improved charge separation occurred at the Cu₂O/TNA, Cu₂O/Ti, and Cu₂O/FTO junctions. The improved photocatalytic properties of Cu₂O/TNA compared with TNA was attributed to the UV-visible light absorption of Cu₂O.

Keywords: Substrate-dependence, Photocatalytic properties, Cu2O, TiO2 nanotube arrays, heterojunction