A two dimensional hierarchically porous MOF-Cu with large lateral size via amino-groups regulated hydrolysis strategy and its superior photocatalytic reduction of CO2

A two-dimensional hierarchically porous (2D HP) MOF-Cu layer with a large lateral size was prepared by the amino-groups regulated hydrolysis strategy. The resultant large 2D MOF-Cu layer has many defects owing to the replacement of partial ligands via -OH. 2D HP MOF-Cu large layer showed significantly enhanced photocatalytic activity under full-spectrum irradiation (with the CO production rate about 4.4 times that of the original 3D MOF-Cu sheets). DFT results confirmed that the defective 2D HP MOF-Cu large layer exhibited the new defective state in the valence band, which narrowed the band gap, broadened the light absorption range, promoted the electron transfer, and decreased the Gibbs free energy barrier for COOH* → CO* (about 0.61 eV). This work provides a facile method for the preparation of the defective 2D HP MOFs large layers via the regulation of amino groups from the organic ligands and elucidates the mechanism for improved photocatalytic efficiency.