2D Cu-FeTCPP MOF assembled on ZnTi-LDH to construct 2D/2D direct Z-scheme heterojunction for enhanced photocatalytic CO2 reduction

The artificial photocatalysis to convert CO2 into renewable fuels has been of great significance in solving climate crisis and depletion of fossil fuels. The development of Z-scheme photocatalyst is crucial to achieve efficient photocatalytic CO2 reduction. Herein, a 2D/2D Z-scheme ZnTi-LDH/Cu-FeTCPP MOF heterojunction is designed for photocatalytic CO2 reduction without photosensitizer and organic sacrificial agent. The optimized ZnTi-LDH/Cu-FeTCPP MOF photocatalyst exhibits attractive activity with a CO yield of 37.80 μmol•g−1, which is 28 and 26 times higher than those of ZnTi-LDH and Cu-FeTCPP MOF respectively. The increased photocatalytic activity is attributed to the contact of Cu-FeTCPP MOF and ZnTi-LDH, which enhances the CO2 adsorption and light utilization. More importantly, the internal electric field created at the contact interface is capable of establishing a direct Z-scheme heterojunction in the ZnTi-LDH/Cu-FeTCPP MOF hybrid to separate photogenerated carriers and boost the redox reactions. Additionally, cycling tests confirm its favorable stability. This study strategies designing effective LDHs/MOFs Z-scheme heterojunction photocatalysts toward CO2 photocatalytic reduction.