Brno Ph.D. Talent 2023 - František Zelenák – From chemist to successful physicist

Since 2009, Brno city has supported young talented scientists in their careers. This year, 25 scientists from four Brno universities received the Brno Ph.D. Talent award. In the following three years, all awardees will receive a stipend 330 000 CZK.

Since the existence of Brno Ph.D. Talent project, the doctoral students from the Department of Physical Electronics have been successful several times already: Pavel Souček, Tomáš Svoboda, Adam Obrusník, Matej Fekete, Lukáš Kusýn, Štěpánka Kelarová and Július Vida. František Zelenák and Kryštof Mrózek, therefore, increase the prestige of DPE research and contribute to the good name of the doctoral study program Plasma Physics.

Let us introduce František Zelenák:

Can you tell our readers about yourself? Where are you from?

I am from Bratislava, where I attended a mathematically oriented high school - Gymnázium Jura Hronca. Since childhood, I have been interested in the workings of the world around me. Therefore, science was a clear path for me and my life choices. My favorite high school subject was chemistry because it is the closest to the material world around us. I chose to study chemistry at university. In that time, in 2013, a brand new Masaryk university campus in Brno was finished. That was my deciding factor, and I went to study in Brno.

In chemistry, I chose the path of analytical chemistry. It is like a bridge between physics and chemistry. This path looked the best for me, and I learned many methods for understanding the composition of the world around us. Through this, I have developed an analytical mind. From the beginning of my studies at MUNI, I oriented myself toward nanotechnologies, specifically graphene. Thanks to my studies, I had access to many scientific publications on this topic through university email. Therefore, I broaden my knowledge in nanotechnology which I consider to be the building stone for Industry 4.0.

What is your field of study? How did you end up studying at the DPE?

Currently, I am studying a postgraduate program named Plasma physics. During my master's study, I took the opportunity to start researching graphene at the Department of Physical Electronics by coincidence. I even did my diploma thesis (https://is.muni.cz/auth/th/ysuhc/) on applying graphene in analytical chemistry. Specifically, it was the application of reduced graphene oxide as a substrate or matrix suitable for effective laser ionization and subsequent analysis using mass spectrometry, so-called Substrate Assisted Laser Desorption/Ionization Mass Spectrometry (SALDI-MS).

plasma as a matter is not covered. Plasma is intriguing, and it is a field where it is still so much to explore and understand. I decided to continue my research on graphene at the DPE. Further in the research, we even made a discovery that we even applied for a patent. I continue my research as a doctoral student. The process we are studying still needs to be understood. They are not much described in scientific papers or books. Its physical base implies a sizeable industrial potential for graphene applications. This problem still needs to be solved even 20 years after discovering graphene.

What does the Brno Ph.D. Talent award mean to you?

It is a gratifying feeling to receive this prize. I realize now that our work with my supervisor Richard Krumpolec can be significant to global human research in material science. Practically the stipend will cover my living expenses due to increased inflation.

What is your project about? What is your job?

We figured out a way how to easily and quickly (within few seconds) reduced graphene oxide using plasma, meaning getting rid of the oxygen atoms. Graphene oxide is relatively simple to create and a standard product on the market. Its con is that it is not electrically conductive compared with pure graphene, limiting its potential. It is due to the plasma reduction that we were able to improve the electric properties creating the reduced graphene oxide.

The primary limitations of other graphene oxide reduction methods are the length of the processes (even hours), high demand on the machinery, and energy consumption. Simply said, these processes make it unsuitable for mass industrial production. Our approach also excels in the potential of simple functionalization using plasma, e.g., adding other elements such as nitrogen into graphene and improving its properties for specific application needs. Other methods of reduction can not do this or only in limited form.

My project is based on understanding how graphene oxide reduction using plasma works and how to functionalize the process most effectively. At the end of the project, I would like to use our method for manufacturing devices prototypes in green technology, such as solar cells, supercapacitors, sensors or water filters.

The potential of our manufacturing process for reduced graphene oxide is theoretically limitless. It can even be viewed as a new step in metallurgy, where it was first copper, then bronze, and lastly iron. We are not trying to create one but an entirely new improving material for various products.