Direct Electrochemical Synthesis of Metal‐Organic Frameworks: Cu3(BTC)2 and Cu(TCPP) on Copper Thin films and Copper‐Based Microstructures

In this research, the MOFs Cu₃(BTC)₂ and Cu(TCPP) were electrochemically synthesized via anodic dissolution of Cu thin films and well-defined Cu-based microstructures as the only Cu source in the partial electrochemical synthesis. A MOF coating on the microstructures was obtained, keeping the original size and shape of the initial microstructures.

Abstract

Cu thin films and Cu₂O microstructures were partially converted to the Metal-Organic Frameworks (MOFs) Cu₃(BTC)₂ or Cu(TCPP) using an electrochemical process with a higher control and at milder conditions compared to the traditional solvothermal MOF synthesis. Initially, either a Cu thin film was sputtered, or different kinds of Cu or Cu₂O microstructures were electrochemically deposited onto a conductive ITO glass substrate. Then, these Cu thin films or Cu-based microstructures were subsequently coated with a thin layer of either Cu₃(BTC)₂ or Cu(TCPP) by controlled anodic dissolution of the Cu-based substrate at room temperature and in the presence of the desired organic linker molecules: 1,3,5-benzenetricarboxylic acid (BTC) or photoactive 4,4′,4′′,4′′′-(Porphine-5,10,15,20-tetrayl) tetrakis(benzoic acid) (TCPP) in the electrolyte. An increase in size of the Cu micro cubes with exposed planes [100] of 38,7 % for the Cu₂O@Cu₃(BTC)₂ and a 68,9 % increase for the Cu₂O@Cu(TCPP) was roughly estimated. Finally, XRD, Raman spectroscopy and UV–vis absorption spectroscopy were used to characterize the initial Cu films or Cu-based microstructures, and the obtained core-shell Cu₂O@Cu(BTC) and Cu₂O@Cu(TCPP) microstructures.

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