TiO2 Film/Cu2O Microgrid Heterojunction with Photocatalytic Activity under Solar Light Irradiation

Coupling a narrow-band-gap semiconductor with TiO2 is an effective method to produce photocatalysts that work under UV−vis light irradiation. Usually photocatalytic coupled-semiconductors exist mainly as powders, and photocatalytic activity is only favored when a small loading amount of narrow-band-gap semiconductor is used. Here we propose a heavy-loading photocatalyst configuration in which 51% of the surface of the TiO2 film is covered by a Cu2O microgrid. The coupled system shows higher photocatalytic activity under solar light irradiation than TiO2 and Cu2O films. This improved performance is due to the efficient charge transfer between the two phases and the similar opportunity each has to be exposed to irradiation and adsorbates.