Porous-structured Cu₂O/TiO₂ nanojunction material toward efficient CO₂ photoreduction

Porous-structured Cu₂O/TiO₂ nanojunction material is successfully fabricated by a facile method via loading Cu₂O nanoparticles on the network of a porous TiO₂ substrate. The developed Cu₂O/TiO₂ nanojunction material has a size of several nanometers, in which the p-type Cu₂O and n-type TiO₂ nanoparticles are closely contacted with each other. The well designed nanojunction structure is beneficial for the charge separation in the photocatalytic reaction. Meanwhile, the porous structure of the Cu₂O/TiO₂ nanojunction can facilitate the CO₂ adsorption and offer more reaction active sites. Most importantly, the gas-phase CO₂ photoreduction tests reveal that our developed porous-structured Cu₂O/TiO₂ nanojunction material exhibits marked photocatalytic activity in the CH₄ evolution, about 12, 9, and 7.5 times higher than the pure TiO₂, Pt–TiO₂, and commercial Degussa P25 TiO₂ powders, respectively. The greatly enhanced activity can be attributed to the well designed nanojunction structure combined with the porous structure, which can simultaneously enhance the charge separation efficiency and facilitate the CO₂ adsorption. (paper)