Preparation and Photocatalytic Activity of ZnO/Fe₂O₃ Nanorod Arrays and ZnO/NiO Nanotube Arrays

ZnO/Fe₂O₃ nanorod arrays (NRs) and ZnO/NiO nanotube arrays (NTs) are synthesized on Si substrates by using a facile two-step growth method. The absorption spectrum of the ZnO/Fe₂O₃ NRs shows significant absorption in the visible light region. Their photocatalytic properties are evaluated by the degradation of methylene blue (MB). It is found that the ZnO/Fe₂O₃ NRs display higher photocatalytic activity than the ZnO/NiO nanotube arrays under UV-vis light irradiation. This is most likely attributed to an effective separation of photoelectrons and holes.