Ever since completing a graduate fellowship at the Department of Energy’s (DOE) National Energy Technology Laboratory in 2018, Sixbert Muhoza had further research at a DOE national laboratory in mind. As a Walter Massey fellow at DOE’s Argonne National Laboratory, Muhoza is now studying a class of chemical materials called MXenes, which hold promise for use in energy technologies such as batteries, among others.
As a high school student, Muhoza was awarded a presidential college scholarship by his home country, Rwanda. He earned a bachelor’s degree in chemistry from Mississippi’s Belhaven University and then a Ph.D. in materials chemistry from Wake Forest University in North Carolina. As a scholar in Argonne’s Applied Materials Division, he has used advanced microscopy and other tools available in both the division and the Center for Nanoscale Materials, a DOE Office of Science user facility, to study the structure and properties of MXenes. Here, he discusses his research and why it matters.
“I believe that viewing science through the lens of its real-life usefulness provided me with the motivation and meaning that I needed to focus on science classes and research.” — Sixbert Muhoza, Argonne scholar
Q: What are you working on at Argonne?
A: Right now, I’m working on a new class of materials called MXenes, which are two-dimensional metal carbides and/or nitrides with high electrical conductivity, among other properties. I’m studying these MXenes from three angles. First, we are exploring how we can develop new ones with novel composition and complexity. Second, we want to use them to make new and better electrodes — the positive and negative ends that charge and discharge energy — for batteries. And third, we are studying how we can use them to convert carbon dioxide into useful fuels, such as ethanol.
Q: What drew you to apply to the Walter Massey fellowship?
A: At the time, I was a postdoctoral researcher at Wake Forest University, and I knew that I wanted my next chapter to be at a national lab. So, I started looking at opportunities and talking to different people at different national labs. One of them, Zachary Hood, who’s now my supervisor and mentor, told me about the fellowship programs available at Argonne and encouraged me to apply. The Walter Massey Fellowship was most intriguing to me because it was going to provide me with an opportunity to conduct research and pursue outreach initiatives to underrepresented groups in science with the support of a national lab.
Q: Why is your work important?
A: My work focuses on developing materials for electrochemical applications. Since most renewable energy technologies use or rely on electrochemical principles, my work provides a significant contribution to the fight against the impact of climate change. For instance, developing high-capacity batteries, one of my research areas, is key to achieving wide adoption of electric vehicles and solar power, which will substantially reduce the release of carbon dioxide in the atmosphere. Then, my work on carbon dioxide reduction brings forward a method to attack the same problem from the opposite end, where we can capture the carbon dioxide already released in the atmosphere and convert it into useful chemicals such as ethanol or methane.
Q: How did you get interested in electrochemical research?
A: When I was in high school, I wanted to go to medical school and had been admitted into one after graduation. However, when I was awarded the presidential scholarship and came to the United States, my outlook changed. Being a doctor and treating people is very important, but I became more interested in work that would change how people lived. As I saw it, scientific innovation is the reason why people in this generation are living better than those in previous generations, and I wanted to contribute to that progress. I also developed a curiosity about how the products that I used in my daily life were made. So, I became interested in work where I could develop concepts that would turn into new products and technologies.
Before going to graduate school, I realized that electrochemistry would enable me to pursue both of those interests. It covers a large number of applications, ranging from small portable electronics to large power plants. By specializing in it, I could work on a variety of useful technologies that will change our ways of life. I have worked on fuel cells, batteries and carbon dioxide reduction thus far; all three are green energy conversion technologies that use electrochemistry principles and that will change the way we live in the future.
Q: What do you like about being at Argonne?
A: National labs are a sweet spot between academia and industry, since they provide opportunities to conduct fundamental research and applied research, sometimes with an industry partner. I like having several options at my disposal and look forward to maximizing the opportunity. I also like having such a large network of scientists at Argonne to learn from, as I want to keep growing as a scientist and leverage all the resources available here to deliver the best research. I may be biased, but I think Argonne is the best of all the national labs. You get the benefit of being near a great city like Chicago and then have access to great resources such as the user facilities as well as the large network of talented scientists. It’s a great place to be for anybody who wants to grow as scientist.
Q: Looking ahead, what do you hope will be the outcome of this fellowship?
A: What our research is focused on now is understanding the fundamental structure of our novel MXenes and how that affects their properties. We’re ultimately aiming to establish a structure-property relationship in such a way that we understand how to customize a MXene structure to enhance a specific property for a given application. Not only is that going to be beneficial for developing more efficient electrodes for batteries and electrolyzers, but it will also help guide the general scientific community on materials development methods.
Q: What do you like to do for fun?
A: People who know me know that I love sports. But what they don’t know is that I’m actually a good singer — maybe good is an exaggeration, but my research team does karaoke every chance we get.
Q: What advice would you give to students who are interested in following a path like yours?
A: I would tell them to develop an intrinsic interest in science by connecting it to a real-life application. For instance, in high school, I had clarity in science classes because I knew they would get me into medical school which was my goal at the time. Then in college, I associated science with developing technologies and products that change people’s lives. I believe that viewing science through the lens of its real-life usefulness provided me with the motivation and meaning that I needed to focus on science classes and research.
I would also tell them to use the resources that are available to them, starting with their professors and academic advisors, to identify the best path they can pursue to achieve their goals. Once they know or have an idea of what they want to do, I would advise them to reach out to people who are already doing the same type of work. You would be surprised by how much you can learn from people whose footsteps you want to follow. They can provide information on activities, programs, internships and other opportunities that would be beneficial to your professional journey.
About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.