A group of chemists at Clemson University have created a brand-new, two-dimensional, electrically conductive metal-organic framework (MOF), a discovery that could advance energy and modern electronics technology.
The team’s findings were published in the journal Angewandte Chemie in the paper titled “Electrically Conductive π-Intercalated Graphitic Metal-Organic Framework Containing Alternate π-Donor/Acceptor Stacks.”
MOFs are nanoscale structures that resemble tiny dwellings and are constructed from metal ions connected by organic ligands. The structures have a remarkable amount of internal surface area and are usually hollow and porous.
As a result, MOFs can accelerate chemical events, store guest molecules, and deliver medications in a precise manner. Some MOFs are even electrically conductible, making them candidates for next-generation semiconductors.
“We need new materials for semiconductors for electronics and energy technologies, and this class of materials has shown great potential,” said Sourav Saha, an associate professor in the Department of Chemistry, who led the study. “These materials (MOFs) are much easier to synthesize, process and tune their electronic and optical properties than traditional inorganic semiconductors.”
Dr. Saha’s work is helping to deliver on the promise that metal-organic framework materials offer for improving a wide range of technologies, including batteries, solar cells, and chemical and pharmaceutical production. His clever introduction of electric conductivity in these open framework materials is a tour-de-force of molecular design. It is exciting to see these advances emerge from Clemson’s research enterprise.
Professor Stephen Creager
The biggest obstacle to gain high framework conductivity is their porosity.
“That is really challenging to make porous materials electrically conducting because the charges don’t flow through the pores or the empty space,” Saha said. “That is the holy grail. That is the main challenge of the field.”
Chemists adopt different strategies to make these materials electrically conducting. Charges may move through organic ligands that are tightly spaced together or through chemical bonds.
“Typically, most of these MOFs that are electrically conducting have either through-bond or through-space conduction pathways. What we accomplished here was to combine these two pathways into a single 2D material,” he said.
The progenitor MOF, which lacked such effective out-of-plane conduction routes, had conductivity that was 10 to 15 times lower than that of the new MOF.
“Dr. Saha’s work is helping to deliver on the promise that metal-organic framework materials offer for improving a wide range of technologies, including batteries, solar cells, and chemical and pharmaceutical production. His clever introduction of electric conductivity in these open framework materials is a tour-de-force of molecular design. It is exciting to see these advances emerge from Clemson’s research enterprise,” said Stephen Creager, associate dean and professor of chemistry in the College of Science.
Saha’s research team at Clemson included postdoc Ashok Yadav and graduate students Shiyu Zhang and Paola Benavides. Wei Zhou of the National Institute of Standards and Technology’s Center for Neuron Research provided computational support and validation to Saha’s experimental work.
