CsPbBr3 perovskite based tandem device for CO2 photoreduction

Abstract

The design of efficient photocatalytic devices is of great significance to achieve low-cost carbon dioxide reduction into solar fuels. Herein, directional charge-carrier migration is realized by introducing a CO2 reduction device with a tandem structure made up of g-C3N4 and an inorganic lead-perovskite (CsPbBr3). This photocatalytic device shows a significantly increased CO2 photoreduction rate in a humid gaseous CO2 system when compared to the parental g-C3N4 layer. This “full artificial photosynthesis” thereby generates fuel molecules and oxygen from water and CO2, only, without any co-catalysts or sacrificial agents. To our surprise, the device maintains greater than 90% of the CO production yield after 5 days continuous irradiation. The existence of internal electric field is confirmed, which drive the directional movement of photogenerated charge-carriers with the perovskite being reductive, while the carbon nitride with its enormous oxidation stability is covering the oxidation processes. This represents a promising possibility for the practical application of CO2 photoreduction with scalable devices.