The Balance between Conductivity and Electro-/Photo-Catalytic Performance of Guest-Incorporated Metal-Organic Frameworks

Abstract

Porphyrin plays an important role in being a chromophore in photocatalysis and it was also investigated for years as a competent candidate in electrocatalysis when metals are loaded. In addition to being used as individual molecules, porphyrin can also be assembled into corners and cages. Moreover, with the development of Metal-Organic Frameworks (MOFs), a type of hybrid materials containing metal clusters and organic linkers, porphyrin has become one of the key building blocks when we consider making MOFs a good electro-/photo-catalyst. However, most MOFs possess insulating metal clusters as nodes which lead to the insulating nature of the whole framework. The insulating nature of MOFs hinders sufficient electro-/photo- catalytic performance. The key advantage of MOFs, on the other hand, is that they offer high loading of active sites, large cavities for great accessibility, and rigid frameworks can, if constructed properly, prevent active moieties from sintering. Herein, we evaluated the competition between conductivity and the electro-/photo- catalytic performance of porphyrin containing MOFs. The conductivity of these porphyrin containing MOFs was enhanced by guest incorporation. After modification, the electrical conductivity and electro-/photo- catalytic performance were measured separately. Surprisingly, these MOFs do not require a significant conductivity to generate a competitive electro-/photo-catalytic performance.