Research into plasma and nanomaterials can help address current environmental problems such as water pollution. In this interview František Zažímal and his supervisor Tomáš Homola explain the contribution their applied research can make, why the reality of science is often not only about successes, and how important it is to persevere and not give up.
He works as an associate professor at the Department of Plasma Physics and Technology at the Faculty of Science of Masaryk University (SCI MUNI), where he is also Deputy Director for applied research at the CEPLANT center. He also works part-time at the Institute of Plasma Physics of the Czech Academy of Sciences in Prague.
He completed his doctoral studies at Comenius University in Bratislava and during his career worked at the Singapore Institute of Manufacturing Technology (A*STAR) in Singapore, at Lappeenranta University of Technology in Finland, and at Joanneum Research in Austria.
Between 2022–2025, he obtained a Marie Skłodowska-Curie Actions (MSCA) project focused on nanomaterials for water treatment. At present, in addition to František Zažímal, he is also the supervisor of three other doctoral students.
At the Department of Plasma Physics and Technology of the SCI MUNI, he recently completed the doctoral programme in Plasma Physics. In his doctoral thesis, he focused on research into new technologies based on low-temperature plasma and nanomaterials for wastewater treatment.
During his doctoral studies, he has so far published 25 articles in impact-factor Q1/Q2 journals as first author or co-author. Among other things, he mentored bachelor’s students and professionally supervised the research of a secondary school student who received a number of prestigious awards for her work.
For his outstanding achievements during his doctoral studies, he received the Dean’s Award of the SCI MUNI for the best student in a doctoral study programme.
You have been collaborating together for seven years. In your opinion, what does an ideal relationship between a supervisor and a doctoral student look like?
I have known František since his master’s studies, when I supervised his thesis focused on printed magnetic layers. Even at that time, it was clear that he did not belong among students who simply complete assignments. He worked very systematically, was able to independently study the literature, and often came up with his own interpretations or alternative perspectives on a problem. For a supervisor, this is an important moment, because you see that the student does not passively adopt knowledge, but tries to confront it with experiment and formulate their own hypotheses.
In my opinion, the ideal relationship between a supervisor and a doctoral student is about the gradual assumption of responsibility. Independence and the ability to formulate one’s own scientific questions are key for doctoral studies – and this is precisely the direction in which František grew from the very beginning. He gradually assumed more and more responsibility, not only for the experimental programme itself, but also for the direction of topics, publications, and international contacts.
What was important was that he did not perceive this independence as isolation, but as a natural part of scientific work. The ability to plan one’s own research, communicate with foreign partners, and at the same time maintain methodological discipline is a clear sign of scientific maturity. At such a moment, the supervisor rather corrects the direction than manages every step – and that is probably the best indicator that the doctoral student has surpassed the standard framework of expectations.
You asked what an ideal relationship between a supervisor and a doctoral student looks like. First, I will answer the question of what the mutual professional relationship between a supervisor and a doctoral student – or actually even a student at any level – should not look like.
During my studies, I came into contact with many doctoral students at both national and international levels, and in discussions we repeatedly got to this very topic. As the main problem, I often heard that the supervisor does not have time to devote to the doctoral student or that they have poor financial conditions compared to the amount of work. On the other hand, you can sometimes hear complaints from supervisors, for example that the student does not work in accordance with their guidance.
Because I myself became a supervisor during my doctoral studies, I think that I at least partially understand the problems of both sides.
A professional relationship between a supervisor and a student should not look like one of the two sides being dissatisfied. In the end, it actually does not matter with what specifically, if both sides cannot find a way out.
In my opinion, the key to finding a path towards an ideal mutual relationship is proper communication and mutual empathy. Ideally, even before the potential start of doctoral studies, it should be clear what the expectations of the doctoral student and the supervisor are regarding the focus of the research and the manner of cooperation.
From the beginning of my doctoral studies, I had the advantage that I had already collaborated with Associate Professor Homola during my master’s thesis, and therefore I could assess for myself whether such cooperation would also suit me in the future.
Personally, I like to organise my work independently, although consultations with my supervisor regarding hypotheses or methodology were very beneficial and I gladly used these opportunities frequently. This was crucial for me – I gained the freedom to verify and implement my own ideas, while at the same time receiving valuable feedback that helped guide me.
In addition to valuable consultations, I must also appreciate that Associate Professor Homola showed confidence in my work and helped ensure high-quality conditions in terms of laboratory equipment, access to advanced laboratory methods, valuable collaborations with research teams at both local and international levels, and additional financial support, without which I could hardly have focused solely on research.
By the way, conditions for doctoral students are a different and complex topic. In this regard, I am grateful that after years there is finally change and movement towards better conditions for doctoral students in the Czech Republic.
Your research concerns plasma, nanomaterials, and water treatment. What exactly does it involve?
We operate at the interface of plasma physics, materials research, and environmental technologies. Our research is built on a solid foundation of fundamental science, but we try to choose topics that at the same time have a natural overlap with real technological challenges – typically in the form of new solutions for water treatment and purification. František is deeply involved in this area at the level of materials and processes, so I will leave the details to him.
Within our research, we focus on the development and testing of new technologies for water treatment, especially with a focus on wastewater treatment. We also study the processes and properties of nanomaterials responsible for the degradation of pollutants. Our goal is to develop materials and procedures that would overcome the limitations of conventional technologies used in wastewater treatment plants.
The main problem of current processes, especially at the tertiary treatment stage, is their insufficient efficiency in removing certain substances that pose a risk to the environment and human health. Unfortunately, these substances subsequently escape into watercourses. An example is antibiotic residues, which contribute to the development of antibiotic resistance, one of the current challenges of modern medicine.
Our research primarily focuses precisely on technologies aimed at removing antibiotics. We use advanced oxidation processes based on the degradation of pollutants using highly reactive oxygen and nitrogen species, especially radicals such as hydroxyl radicals or sulfate radicals.
We carry out these processes through photocatalysis using nanomaterials based on graphitic carbon nitride activated by light, peroxymonosulfate activation using nanomaterial catalysts, or the application of low-temperature plasma.
In addition to advanced oxidation processes, we also study the removal of pollutants using biocompatible adsorbents prepared, for example, from residual biomass of fruit crops – so-called biochar.
I consider it important to mention that in our research we are not satisfied merely with results in model systems of pollutants in distilled water, where research by various laboratories testing new technologies often ends, but we also test the treatment of real wastewater.
To what extent is your research influenced by current social or legislative changes?
Applied topics often arise precisely in response to regulatory changes. In the field of water, in recent years the EU directive on urban wastewater has been expanded to include requirements for the removal of micropollutants and the monitoring of microplastics or perfluorinated substances. For scientists, this creates a clear signal of where there is demand for new technologies.
I personally dealt with a similar topic within an MSCA project focused on nanomaterials for water treatment, so I know how quickly priorities can change.
For our group, this means that František’s topic has a clear applied overlap and at the same time stands on a solid foundation of fundamental research – in the long term, this is the most sustainable combination.
In addition to the recent revision of the EU Directive already mentioned by Associate Professor Homola, there are several other factors that significantly motivate our research.
First, the global population is facing increasing water scarcity. I consider the findings of the latest 2025 United Nations report particularly alarming: approximately four billion people worldwide – roughly half of the global population – experience severe water scarcity for at least one month each year.
The negative consequences of insufficient access to drinking water or adequately clean water are, of course, substantial, ranging from reduced crop production to the development of diseases associated with dehydration. I would rather not alarm you further with statistics on mortality or the decline in quality of life linked to water scarcity on a global scale.
In addition to the uneven distribution of water resources across continents and individual countries, water scarcity is also significantly exacerbated by population growth, technological and economic development, global warming, and the pollution of water bodies.
One of the objectives of the United Nations agenda is the fulfilment of the Sustainable Development Goals by 2030, which, among other priorities, focus specifically on ensuring access to clean water and increasing the efficiency of wastewater recycling for various applications, whether for irrigation of urban green areas, industrial production, or agricultural irrigation.
Research and development of efficient and sustainable wastewater treatment technologies can make a contribution to achieving these goals.
As part of my doctoral thesis, I prepared an analysis of the technological level of municipal wastewater treatment plants at both the global level and the level of individual states.
This analysis shows that at present conventional wastewater treatment plants use advanced technologies for the treatment of persistent pollutants – for example antibiotics, other pharmaceuticals, perfluorinated substances, or microplastics – to a very limited extent.
For example, in the EU it can be estimated that approximately twenty percent of all municipal wastewater treatment plants use tertiary technology for the disinfection of pathogenic microorganisms by chlorination or UV radiation. The disinfection of microorganisms or partial mineralisation of pollutants using ozonisation is used only to a very limited extent in several dozen treatment plants.
Considering the technological and economic status of the EU, the technological level of municipal wastewater treatment plants is generally low even for this grouping of states.
This is precisely why we now have the revised EU directive, which will lead to the modernisation of municipal wastewater treatment plants and efforts to treat and utilise such water more efficiently.
I could continue the discussion further, for example regarding the situation in South America, Africa, or Asia. Nevertheless, I hope that from what I have said here it is clear that significant investments can be expected in the research, development, and implementation of new wastewater treatment technologies, not only in the EU, but also globally.
The technologies developed within my doctoral research have real application potential in wastewater treatment plants, and I proposed several specific solutions for their implementation in my doctoral thesis.
So your research is advancing what is in demand in the commercial sector. Should students encounter this aspect of science already during their studies?
The primary mission of doctoral studies is to push the boundaries of knowledge, so commercialisation is not a universal obligation for every doctoral student. However, its importance is growing in fields where research has a natural overlap with technology and practice – and that is also our case.
In my opinion, doctoral students should at least have a basic idea of how a scientific result can be transformed into a real application, even if not everyone ultimately chooses this direction.
František has a great advantage in this regard – during his doctorate he already collaborated with several companies and personally experienced the difference between the academic and industrial environments.
Therefore, I do not think that the role of the university is to “educate entrepreneurs” in the narrow sense of the word. Rather, it should enable doctoral students to understand the broader context of their work.
In an environment such as our CEPLANT centre, they naturally encounter industrial partners, technology transfer projects, or intellectual property protection. Students thus gain a basic orientation in what patent protection, spin-off companies, or the financing of technological development mean.
Not everyone will take this direction, but it is useful for them to have an idea of how a scientific result can be transformed into a real product or process.
From my own experience, I know that a scientist’s first contact with industry is often a cultural shock – the language of publications and the language of the market are different worlds. If a university can ease this transition, it is a great advantage for students.
I was fortunate enough to try collaboration on projects with various companies – both at national and international levels. This brought me very valuable experience and also a new perspective on how research is conducted in companies and in the academic environment.
In industry, at least in my experience, the goal is to achieve results quickly. In contrast, the academic environment goes more in depth – you try to understand processes, optimise experiments, and you have more time.
I must admit that I greatly enjoyed the dynamics of industrial research. It is gratifying to see that research results can very soon be applied in the development of functional technologies.
Personally, I very much appreciate the opportunities provided by the CEPLANT centre regarding experience in industrial research, and I believe it is a great opportunity for students to try a different research dynamic.
Research, however, is often not only about successes when it comes to results. How important are dead ends and failures as well?
I could talk about that for a long time. But briefly; in the first year of my doctoral programme, we were developing magnetic sensors within the concept of printed and flexible electronics, building on my master’s thesis. Unfortunately, even after approximately two years of research, the results did not meet my expectations.
I therefore changed my focus to my current topic of developing and studying technologies for wastewater treatment. It was not the case that I did not make use of my previous experience and knowledge. On the contrary, thanks to my work in materials research, I gained an overview in materials science, which I significantly capitalised on in the following years.
After the first year of my doctorate, I worked on experiments during an internship in Finland. Unfortunately, we rather disproved our hypotheses instead of obtaining positive results. Thus, after a year and a half of demanding work, I essentially had no positive result.
Working for such a long time with great commitment and without positive results is psychologically very demanding, but I also took it as part of personal development. Although I am an optimist by nature, these experiences taught me healthy academic pessimism and a certain perspective.
Dead ends and negative results are a natural part of research. The supervisor’s task is to constantly return attention to the process, not only to the result. Performance is important, especially if we want to publish in high-quality Q1/Q2 journals and succeed in international competition, but this performance must be anchored in a realistic time horizon and in the understanding that scientific growth is uneven.
What František described is, from my perspective as a supervisor, one of the most difficult but at the same time most important phases of a doctorate. I saw what he was going through at the time – the data were obtained precisely and methodologically correctly, but they did not confirm our original hypotheses. For a young scientist, this is typically the moment when they decide whether to remain in scientific work or give it up. It is precisely in such moments that inner resilience and the ability to persevere are revealed – and these are qualities that no course or article can replace.
For me as a supervisor, it is crucial to openly acknowledge this phase. I try to explain to doctoral students that a negative result is not a failure, but information that refines the direction of further research. If the data are obtained precisely and methodologically correctly, they have value regardless of whether they confirm the original hypothesis.
In fact, František’s seemingly “unproductive” year and a half actually created a solid methodological foundation for later experiments and helped him formulate much more precise research questions.
I therefore perceive the balance between demanding performance and protecting a young scientist as a combination of two things: setting ambitious but realistic goals, while at the same time creating a safe space for failure.
Nevertheless, the result of doctoral studies can also be a large number of publications – František is currently the author or co-author of 25 publications in prestigious journals. How is it possible to achieve this?
It was precisely a year and a half after the beginning of my doctoral studies that a turning point occurred. I finally began achieving positive results. Through a long process of learning, the method of trial and error, and, I dare say, my perseverance, we were no longer disproving hypotheses, but confirming them.
At the same time, I would like to emphasise that Associate Professor Homola and I were the first in our research group to begin this research. We had to build laboratory facilities, master the research methodology, and establish collaborations in order to carry out our research. Naturally, this requires considerable effort.
When I first saw positive results, it was a very fulfilling feeling – for me, it became another accelerator of work. From that turning point onwards, the research progressed quickly and we managed to publish a large number of papers in Q1/Q2 journals; in total there are already 25, and another 5 are currently under peer review.
There are several factors behind this number. The topic of water treatment, nanomaterials, and plasma physics is highly perspective because it addresses current social and technological problems. Another factor was that we established high-quality collaborations with many groups. I would like to mention the excellent research with the group of Associate Professor Olivier Monfort and Dr Shalu Atri, which gave me a great deal through our collaboration on water treatment research and nanomaterial development.
Perhaps finally I can also mention the qualities a person needs to achieve such results. Hard work is a matter of course. I am curious, I am interested in how and why things work in depth, I try to do my work precisely, and I do not give up easily.
In the modern conception of doctoral studies, it is very important to be able to organise one’s time and work well, because there are truly many tasks. And at the same time, you must not forget to live outside the office as well; work-life balance is key to maintaining health, well-being, and work performance.
František mentioned the good prospects of the topic and his own curiosity – I would add one more thing that determined that last group of qualities. He is not accustomed to being satisfied with the first functional result. He tries to understand why something works, and only afterwards looks for practical overlap – and that turns data into a story that can withstand the peer-review process of Q1 journals.
Added to this is the international dimension of the field; today our topic has a strong global community, so internships and collaborations naturally lead to co-authorships. For a doctoral student, this is a multiplying effect, but in itself it is not enough – without that inner consistency, it would not come together at this level of quality.
During his doctoral studies, František also supervised bachelor’s students and a grammar school student within the Students` Professional Activities (SPA). What can such experience offer a doctoral student?
Supervising students was more of a pleasure for me. I receive questions from them that I myself often would not even think of. It forced me to think about things from a different perspective, which can sometimes be enriching.
Of course, it comes at the expense of the time you have to devote to it. In our research group, there was demand for young bachelor’s students who could become involved in research. Together with other colleagues, we divided them among ourselves and mentored them.
Secondary school student Anna Podmanická contacted us regarding the possibility of preparing an SPA project connected with plasma research. I responded to the enquiry and became the supervisor of her work. The work and time invested paid off; the student received several awards, including at the international level.
We continue to collaborate with Anna and plan to continue research into water treatment technologies. In this connection, we obtained financial support from a UNESCO grant; Associate Professor Homola and Areej Fatima, my friend and doctoral colleague, will also participate in the project.
The fact that František supervised bachelor’s students and became the supervisor of secondary school student Anna Podmanická, who received international awards, and that together they managed to obtain a UNESCO grant for follow-up research – these are, for me, clear indicators that he is growing not only into a scientist, but also into a future leader.
Mentoring requires something different from one’s own research; the ability to communicate empathetically, organise the work of others, and motivate a team without using authority. František handles this role surprisingly naturally – he is able to pass on to younger students not only technical knowledge, but also a way of thinking about experiments, which is a skill most scientists only acquire after several years of independent work.
When I look back on those seven years of collaboration, what I appreciate most about him is the combination of three things that rarely come together in one person. First, the depth of scientific thinking – he is never satisfied with the first functional result and tries to understand why something works. Second, methodological discipline and perseverance – even during periods when the data did not confirm our hypotheses, he managed to maintain the quality of experimental work. And third, a sense for practical overlap – he has a good understanding of where fundamental research ends and application begins, and he can move smoothly between these two worlds.
This combination is rare in experimental physics and materials research and is the main reason why I see potential in him for an independent scientific career.
At the same time, František is a representative of the generation of young scientists that gives me great hope for the future. They are internationally oriented, naturally work in English, are not hesitant to establish contact with foreign groups, and perceive interdisciplinarity as something self-evident.
At the same time, they think strongly about the social and environmental impact of their work – it is not enough for them to publish a high-quality article; they want to understand where their research can realistically be applied.
The shift from a hierarchical model of supervision to partnership is typical for this generation, and in my opinion it is a change for the better.
If I were to characterise František in one sentence, he is a scientist who is able to combine the depth of fundamental thinking with an orientation towards real impact, while naturally growing into the role of a leader of the next generation.
For the university and for the CEPLANT centre, such a graduate is an ideal example of what the preparation of a new generation of scientific researchers should look like – and I am glad that I was able to participate in his journey for seven years as his supervisor.
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