Iron-based metal-organic frameworks (MOFs) for visible-light-induced photocatalysis

Photocatalysis is one of the best solutions to solve the problems of global energy shortage and environmental deterioration since it can utilize the abundant and ubiquitous solar light for chemical transformations. In addition to traditional semiconductor-based photocatalysts, metal-organic frameworks (MOFs), a class of micro-mesoporous hybrid materials, are recently emerging as a new type of photocatalytic materials due to their unique structural characteristics. Among all the MOFs, Fe-containing MOFs are extremely appealing in photocatalysis since most of the Fe-based MOFs are visible light responsive due to the existence of extensive iron-oxo (Fe-O) clusters. In addition, Fe is an earth-abundant metal and Fe-containing complexes are commonly used in catalysis and photocatalysis. In this short review, we summarized the recent progress in using Fe-based MOFs for several photocatalytic applications, including pollutants degradation, water oxidation/reduction, CO2 reduction and organic transformations, with a focus on their different light-harvesting properties as compared with that of Ti- and Zr-containing MOFs as well as the structural influence on photocatalysis due to the existence of the diversified Fe-based MOFs. We hope that such a review can stimulate intensive research for rational design of Fe-based MOFs, one of the most promising MOF-based systems, for photocatalysis.