Enhanced Electrocatalytic CO₂ Reduction Over 2D Conjugated Cu MOF via Doping with Carbon Nanotubes

2D conjugated metal–organic frameworks (2D c-MOFs) are regarded as a kind of promising functional material due to their highly crystalline porous structure and excellent planar π-conjugation, which have found application in many areas. 2D c-MOFs consist of transition metals and planar fused aromatic rings. Due to the limited choice of metal elements and organic ligands, there is only a few 2D c-MOFs have been reported, which poses a great challenge to fully release its potential in electrocatalysis and other aspects. On the other hand, defects have proved to be an important role in the development of metal–organic frameworks. To the best of our knowledge, a deliberate introduction of defects in 2D c-MOFs has not been reported. Herein, we first realized the introduction of defects to 2D conjugated MOFs with a nonstoichiometric reaction condition. With a series of characterizations, defective sites within the structure of defective CAT-Cu (d-CAT-Cu) were finally confirmed. In the last part, we doped carbon nanotubes (CNT) in d-CAT-Cu to enhance the material’s conductivity and increase the current density of the electrolysis. Meanwhile, the Faradaic efficiency of different products was tuned. Finally, the introduced defects in 2D c-MOFs have a significant influence on the performance of the electrocatalytic carbon dioxide reduction. This work provides a new path for the development of 2D c-MOFs.