Highly selective CO2 capture and photoreduction over porous carbon nitride foams/LDH monolith

Abstract

Sunlight-driven photocatalytic CO2 into useful carbon compounds is an ideal way to mitigate the greenhouse effect. However, this strategy is limited by poor light absorption and rapid photoexcited electron-hole recombination of traditional photocatalysts. Here, a g-C3N4 (CN) foam/LDH heterojunction monolith (NCF) was fabricated by growing NiFe-LDH in situ on the porous CN foam substrate. The composite had good air permeability and light transmittance, which improves light-harvesting, CO2 capture, and interfaces charge transfer of the NCF. The results show that the NCF catalyst has good CO2 adsorption performance (1.52 mmol g−1) and enhanced CO2 photoreduction activity (55.1 μmol g-1h−1), which is ∼ 10 times higher than that of pure LDHs powder. Furthermore, the practical applicability of the NCF monolith with different thicknesses is illustrated via the CO2 photoreduction test for the first time. This work could shed light on the development of dual-functional materials for efficient capture and photoreduction of CO2.