Enhancing energy transfer by regulating electron transport pathways in semiconductor metal-organic frameworks

Photocatalysis is an effective approach to convert solar energy into chemical energy using semiconductor materials. However, the fast recombination rate of electron-hole pairs in these materials leads to low energy utilization efficiency and poor photocatalytic performance. Herein, an iron-based Metal-Organic Framework (Fe-MOF) was constructed via structural tailoring, which has structural advantages such as a one-dimensional Fe-O-triazole chain and strong pi-pi stacking interaction, ensuring a broad absorption range, high electron conductivity (5.53 x 10-4 S m-1), and good photogenerated electron-hole separation efficiency. Fe-MOF as a photosensitizer could facilitate the efficient degradation of tetracycline hydrochloride (TC) under visible light irradiation (e.g., 40 ml of 350 mg L-1 TC showed over 99% degradation in 5 minutes with 5 mg Fe-MOF as the photocatalyst). As a comparison, Zn-MOF, which is isomorphic to Fe-MOF, was prepared using crystal engineering and its photodegradation efficiency was greatly reduced. The results provide a design basis for the development of light harvesting in artificial photosynthesis. Fe-MOF with short-range and long-range photo-induce electron transfer exhibits highly efficient photon utilization, which is validated by excellent degradation of tetracycline hydrochloride.