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A Lehigh University Research team is working to create a new method of producing renewable fuel. Supported by a $2 million grant from the National Science Foundation, using only carbon dioxide, sunlight and water, the team is attempting to perfect a low-cost, environmentally friendly process that could enable the production of methanol—which can be used as fuel for cars, heating appliances, electricity generation and more—at commercial scale. The research is a continuation of chemical and bioengineering professors Steve McIntosh and Bryan Berger work to produce low-cost quantum dots, or QDs, from bacteria.

QDs are small semiconductor particles that were discovered three decades ago. Researchers see their potential in transistors, solar cells, LEDs, lasers, medical imaging and even quantum computing. QDs are also very expensive to make, as they require the use of toxic solvents and costly chemicals at elevated temperatures. Berger’s novel idea to produce QDs from bacteria makes this technology green and affordable.

Through a Lehigh CORE award, McIntosh and Berger worked with Chris Kiely, professor of materials science and engineering and director of Lehigh’s electron microscopy labs, to develop a method of producing QDs at very low cost in bacteria. In their successful EFRI grant, one of only a few awarded nationally last year, they added the expertise of Robert Skibbens, professor of biological sciences, and Ivan Korendovych, assistant professor of chemistry at Syracuse University. Together, the researchers hope that QDs produced through their revolutionary new method can serve as the light-harvesting component of a photocatalyst to efficiently produce methanol fuel.

In their EFRI project, the researchers will couple the QDs with a series of yeast-synthesized enzymes. The QDs will capture the energy in sunlight to generate an energetic electron and electron hole pair. These excited species catalyze the removal of hydrogen from water and carbon from CO2, and produce methanol, a renewable liquid fuel, in a continuous flow process.

The group’s biosynthetic process to produce QDs, said McIntosh, enables control of the dots’ particle size and, with that, the wavelength and energy of light captured. It is not only a dramatically less expensive method than using precious metal catalysts, but it also makes large-scale production of liquid fuels far more feasible.

“The biosynthetic QDs not only enable us to design processes to produce liquid fuel at dramatically reduced cost, but also enable the development of an environmentally-friendly, bio-inspired process unlike current approaches that rely on high temperatures, pressures, toxic solvents and precious metal catalysts,” explained Berger. “Thus, we are able to develop a unique, ‘green’ approach to liquid fuel synthesis that substantially reduces both cost and environmental impact.”

“In the process of trying to achieve our goals on this project, we also will learn valuable lessons that will advance science in other ways,” added McIntosh. “Making QDs more cheaply and efficiently has many applications, such as efficient lighting, biomedical imaging and displays.