Three-dimensional porous Cu2O with dendrite for efficient photocatalytic reduction of CO2 under visible light

Cuprous oxide (Cu2O) is a promising photocatalyst that can reduce CO2 to fuel under visible light irradiation. However, the fast electron-hole recombination and photo-corrosion of Cu2O limit its photocatalytic performance. In order to overcome these two shortcomings of Cu2O, in this work, three-dimensional (3D) porous Cu2O with dendrite structure was prepared by electrodeposition combined with subsequent thermal oxidation. The 3D porous Cu structure was completely transformed to Cu2O with 220celcius annealing, which exhibited high electrochemical specific surface area and good photocatalytic CO2 reduction performance. Compared with non-porous Cu2O structure, 3D porous Cu2O demonstrated 2.5 times increment of concentration of photogenerated carriers (4.3 x 10(20) cm(-3)) and 24-fold enhancement of photocatalytic CO2 reduction to CO (13.4 nmol cm(-2)h(-1)). Especially, some C2 reduction product was observed for the 3D porous structure. This is because the 3D porous structure improves the mass transfer efficiency of CO2 gas, and the nano-sized dendrite structure enhances the efficiency of light capture and photoinduced electron transportation. Furthermore, the rapid separation and high reaction activity of photoinduced holes and electrons result in the anti-photocorrosion properties of 3D porous Cu2O. Therefore, this work not only provides new idea to address the activity and stability of Cu2O, but also develops a facile strategy for photocatalytic reduction of CO2.

Automated summary

In this work, three-dimensional porous Cu2O with dendrite structure was prepared by electrodeposition combined with subsequent thermal oxidation, which showed high photocatalytic performance and anti-photocorrosion properties, improving the efficiency of CO2 reduction.