Winner of Krill Prize 2020
Ben Gurion University of the Negev
Metal-Organic Frameworks (MOFs), a class of porous, high surface area materials, have attracted a great deal of attention due to their exceptional chemical, structural, and functional variety. Their traditional uses have ranged from gas storage and separation, to chemical catalysis and sensing. Until very recently, the fact that the vast majority of known MOFs are considered to be insulators with limited charge carrier nobilities has impeded scientific efforts to use MOFs in electrochemical applications. The lack of conductivity in most MOFs can be attributed to the coordinative nature of their assembly, in which metal ions or nodes are connected to one another by multi-topic, organic linkers acting as non-electroactive spacers. As a consequence, creating a low-energy path for the transport of charges in these materials is very challenging.
however, the development of new approaches for engendering conductivity in MOFs has led to the formation of a new sub-field in MOF chemistry, targeted at the preparation of electrode-supported MOF thin films and their exploitation in electrochemical devices, such as fuel cells (and electrocatalysis in general), batteries, and supercapacitors. In general, MOF thin films offer several important advantages over existing porous electrodes. First, it is possible to obtain an exceptionally high surface concentration of catalytically active sites.
Second, MOFs possess a well-ordered crystalline structure, which gives them great flexibility with respect to pore size, structure, and chemical functionality and permits precise monitoring of electrochemical processes occurring in a variety of confined chemical environments. Nevertheless, highly conductive MOFs are still rare, and thus, charge transport in MOFs remains a bottleneck in the development of this exciting new field of research.
In light of these issues, the aims of our lab research are as follows:
- Design and synthesis of MOF-based electrochemically-active thin films
- To study their structural, chemical and electrical properties.
- To study and evaluate the activity of the obtained MOF-based systems toward electrocatalytic solar fuel-based reactions.
Achieving our research objectives will provide a better understanding of charge transport mechanisms in MOF-based thin films, and will pave the way toward the design of new methods for manipulating and improving their electrical properties. Additionally, studying the chemical, physical, and electronic properties of the MOF-based electrocatalytic systems could lead to ground-breaking developments in this field of research, and will also open up opportunities in other fields such as photovoltaics, electrochemical sensors, batteries and supercapacitors.