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.