Visible-light-induced photocatalytic CO2 reduction over zirconium metal organic frameworks modified with different functional groups

The reduction of CO2into high value-added chemicals and fuels by a photocatalytic technology can relieve energy shortages and the environmental problems caused by greenhouse effects.In the current work,an amino-functionalized zirconium metal organic framework(Zr-MOF) was covalently modified with different functional groups via the condensation of Zr-MOF with 2-pyridinecarboxaldehyde (PA),salicylaldehyde (SA),benzaldehyde (BA),and trifluoroacetic acid (TA),named Zr-MOF-X (X=PA,SA,BA,and TA),respectively,through the post-synthesis modification.Compared with Zr-MOF and Zr-MOF-TA,the introduction of PA,SA,or BA into the framework of Zr-MOF can not only enhance the visible-light harvesting and CO2capture,but also accelerate the photogenerated charge separation and transfer,thereby improving the photocatalytic ability of Zr-MOF for CO2reduction.These results indicate that the modification of Zr-MOF with electron-donating groups can promote the photocatalytic CO2reduction.Therefore,the current work provides an instructive approach to improve the photocatalytic efficiency of CO2reduction through the covalent modification of MOFs.