An international team of chemistry researchers, led by Dr. Laroussi Chaabane and Prof. Bao-Lian Su, has just demonstrated that it is possible to produce "green" hydrogen using natural water and sunlight. These findings have been published in the prestigious Chemical Engineering Journal.

Faced with climate change, pollution, and energy shortages, the search for alternatives to fossil fuels has become a global priority in order to achieve carbon neutrality by 2050. Among the solutions being considered, green hydrogen appears to be a particularly promising energy carrier: it has a high energy density and can be produced without greenhouse gas emissions. Today, most of the world's hydrogen (around 87 million tons produced in 2020) is obtained through costly and polluting electrochemical processes, mainly used by the chemical industry or fuel cells. Hence the major interest in more sustainable methods.

Producing hydrogen and oxygen directly from water using light, a process known as photocatalysis of water, is often referred to as the "Holy Grail of chemistry" because it is so complex to master. At the University of Namur, researchers at the Laboratory of Inorganic Materials Chemistry (CMI), part of the Nanomaterials Chemistry Unit (UCNANO) and the Namur Institute of Structured Matter (NISM), have taken a decisive step forward. They have demonstrated that it is possible to use natural water, and no longer just ultrapure water, to produce green hydrogen under the action of sunlight.

The new material developed is a three-dimensional (3D) photocatalyst based on titanium oxide, graphene, and gold nanoparticles. This 3D architecture allows for better light absorption and more efficient generation of free electrons, which are essential for triggering the water dissociation reaction. One of the main challenges lies in the use of natural water, which contains minerals, salts, and organic compounds that can disrupt the process. To address this challenge, the researchers tested their device with water from several Belgian rivers: the Meuse, the Sambre, the Scheldt, and the Yser.

The performance achieved is almost equivalent to that measured with pure water.  

This is a first in Belgium, opening up concrete prospects for the sustainable use of local natural resources!

The full article, "Synergistic four physical phenomena in a 3D photocatalyst for unprecedented overall water splitting," is available in open access.

This scientific breakthrough also earned Dr. Laroussi Chaabane the award for best poster at the 4th International Colloids Conference (San Sebastián, Spain, July 2025), highlighting the impact and originality of this work.

An international research team

• University of Namur, Faculty of Sciences, UCNANO, Laboratory of Inorganic Materials Chemistry (CMI) and Namur Institute of Structured Matter (NISM), Belgium | Principal Investigator (PI) | Professor Bao Lian SU; Postdoctoral Researcher | Dr. Laroussi Chaabane
• Institute of Organic Chemistry, Phytochemistry Center, Academy of Sciences, Bulgaria
• Department of Organic Chemistry (MSc), Loyola Academy, India
• Free University of Brussels (ULB) and Flanders Make, Department of Applied Physics and Photonics, Brussels Photonics, Belgium
• University of Quebec in Montreal (UQAM), Department of Chemistry, Montreal, Quebec, Canada
• National Institute for Scientific Research - Energy Materials Telecommunications Center (INRS-EMT), Varennes, Quebec, Canada
• Wuhan University of Technology, National Laboratory for Advanced Technologies in Materials Synthesis and Processing, China

At this stage, the study constitutes proof of concept demonstrating the feasibility of the process. It illustrates the excellence of chemical engineering and nanomaterials research at UNamur, as well as its potential for sustainable energy applications. A new study is underway to evaluate the performance of the process with seawater, a key step towards large-scale green hydrogen production.

The analyses carried out were made possible thanks to the equipment available at UNamur's Physico-Chemical Characterization (PC²), Electron Microscopy, and Material Synthesis, Irradiation, and Analysis (SIAM) technology platforms. UNamur's technology platforms house state-of-the-art equipment and are accessible to the scientific community as well as to industries and companies. 

The authors would like to thank the Wallonia Public Service (SPW) for its ongoing commitment to scientific research and innovation in Wallonia, enabling UNamur to develop technological solutions with a significant societal and environmental impact.

From fundamental to applied research, UNamur demonstrates every day that research is a driver of transformation. Thanks to the commitment of its researchers, the support of its partners from all walks of life, funders, industrial partners, and a solid ecosystem of valorization, UNamur actively participates in shaping a society that is open to the world, more innovative, more responsible, and more sustainable.

For several years now, heritage sciences have been experiencing a particularly significant boom. This deeply interdisciplinary field of research aims to foster dialogue between the humanities and natural sciences with a view to improving our knowledge of heritage objects, whether they be parchments, works of art, or artifacts discovered during excavations.

Manuscripts bear witness to ancestral practices and know-how, which unfortunately are poorly documented. It is still unclear why legal documents were preferably written on sheepskin parchment in England from the 13th century until 1925. Among the hypotheses put forward is the fact that sheepskin is whiter, and therefore more attractive, but above all that documents written on it were considered unforgeable due to the tendency of sheepskin to delaminate (any malicious attempt to erase the text would thus be revealed). This delamination property was exploited because it allowed the production of high-quality writing surfaces. It was also used to prepare strong repair pieces used to fill any tears that appeared during the parchment manufacturing process. Understanding why sheepskin delaminates is of interest in the context of traditional parchment preparation techniques, offering valuable insights into the interaction between animal biology, craftsmanship, and historical needs.

Delamination is the phenomenon whereby the inner layers of the skin separate along their interface as a result of mechanical stress. The diagram (a) below shows the structure of the skin, which consists mainly of the epidermis, dermis, and hypodermis. The dermis is divided into two layers, the papillary dermis and the reticular dermis, which contain hair, hair follicles, and sebaceous glands. 

During the parchment manufacturing process, a step following liming involves scraping the skin to remove the hair. This step crushes the sebaceous glands, releasing fats and creating a void where the hair was located (diagram b). 

The study showed that delamination occurs within the papillary dermis itself, in this structurally weakened area, rather than at the papillary-reticular junction as previously assumed. 

The unique nature of the delamination process in sheepskin is highlighted by the skin structure, which differs from that of other animals (calves, goats) used to make parchment, as it has a high fat content associated with a large number of primary and secondary hair follicles. In the study, the presence of fats was confirmed using Raman spectroscopy.

This study combines experimental archaeology and advanced analytical techniques, including scanning electron microscopy (SEM) and micro-Raman spectroscopy, to characterize the delamination process and the adhesion of repair pieces on experimentally produced sheepskin parchment. It benefits from the expertise in archaeometry, biology, chemistry, and physics of the researchers involved.

Beyond its visual and structural implications, delamination has contributed to promoting the use of sheepskin for prestigious documents, improving the surface properties of parchment. The study of the interaction between metal-gallic ink and delaminated sheepskin (wetting experiments) showed that ink diffusion and writing quality are improved, a key finding that provides insight into how surface morphology and composition influence writing performance.

At UNamur, Marine Appart, a PhD student in physics, is conducting this multidisciplinary research on the archaeometry of delamination and repairs on a sheepskin parchment under the supervision of Professor Olivier Deparis (Department of Physics, NISM Institute). 

Also part of the UNamur team are:

• Professor Francesca Cecchet (expert in Raman spectroscopy), Department of Physics, NARILIS and NISM Institutes
• Professor Yves Poumay (skin specialist), Department of Medicine, NARILIS Institute
• Dr. Caroline Canon (histology specialist), Department of Medicine
• Nicolas Gros (PhD student in heritage sciences), Department of Physics, NARILIS and NISM Institutes

Other international experts

• Professor Matthew Collins (world expert in biomolecular archaeology, Department of Archaeology, The McDonald Institute, University of Cambridge, Cambridge, UK)
• Jiří Vnouček (curator and expert in parchment production, Preservation Department, Royal Danish Library, Copenhagen, Denmark)
• Marc Fourneau (biologist) 

This study and the resulting article were inspired by the delamination experiments conducted in 2023 by Jiří Vnouček during a symposium in Klosterneuburg, Austria, in which Prof. Olivier Deparis participated. The symposium was organized by Professor Matthew Collins as part of the ABC and ERC Beast2Craft (B2C) projects.

But it all began in 2014, when the Pergamenum21 project, dedicated to the transdisciplinary study of parchments, was launched.  Pergamenum21 is a project of the Namur Transdisciplinary Research Impulse (NaTRIP) program at the University of Namur. The project received an additional grant in 2016 from the Jean-Jacques Comhaire Fund of the King Baudouin Foundation (FRB).

The projects and events followed one after another, including: 

• May 2014: a transdisciplinary seminar on parchment, the scientific techniques used to characterize this material, and historical questions at the Mauretus Plantin Library (BUMP)
• May 2017: "Autopsy of a scriptorium: the Orval parchments put to the test of bioarchaeology," a transdisciplinary research project co-financed by the University of Namur and the Jean-Jacques Comhaire Fund of the King Baudouin Foundation
• April 2019: a publication in Scientific Reports, Nature group - Jean-Jacques Comhaire Prize: discovery of an innovative technique based on measuring the light scattered by ancient parchments. This technique makes it possible to characterize, in a non-invasive way, the nature of the skins used in the Middle Ages to make parchments
• September 2020: a residential workshop on making parchment from animal skins at the Domaine d'Haugimont – a first in Belgium
• July 2022: a new project on parchment bindings for the restoration workshop at the Moretus Plantin University Library (BUMP) thanks to the Jean-Jacques Comhaire Fund of the King Baudouin Foundation.
• September 2024: a residential symposium-workshop at the Domaine d'Haugimont on the theme of the physicochemistry of parchment and inks using experimental and historical approaches 

Overall, the work of Marine Appart and her colleagues clarifies the structural and material factors that make sheepskin parchment susceptible to delamination and offers new insights into the surface properties of this ancient writing material. UNamur is now establishing itself as a major player in parchment research.

Professor Olivier Deparis, along with several of the researchers involved in this research, are also working on the ARC PHOENIX project.  This project aims to renew our understanding of medieval parchments and ancient coins. Artificial intelligence is used to analyze the data generated by the characterization of materials. This joint study will address issues related to the production chain and the use of these objects and materials in past societies. 

For over 30 years, UNamur, via its Chemistry of Inorganic Materials Laboratory (CMI) headed by Professor Bao-Lian Su, has excelled in fundamental research into catalytic solutions capable of "cleaning" air and water. In 2014, STÛV approached this expertise to design a sustainable, low-cost smoke purification system for wood-burning stoves, in anticipation of the tightening of European standards.

From this meeting was born the R-PUR applied research project, funded by the Walloon Region and the European Union as part of the Beware program, led by Tarek Barakat (UNamur - CMI). Between 2014 and 2017, an innovative catalytic filter was thus developed within the laboratory, in close collaboration with STÛV.

From 2018 to 2024, the technologies patented by STÛV and UNamur and the pollutant measurement equipment were gradually transferred to STÛV, at the same time as Win4Spin-off and Proof of Concept funding enabled technological and commercial maturities to be increased to meet market needs. These steps led to laying the foundations for a new Business Unit at STÛV, with the hiring of Tarek Barakat as Project Manager, and raising investments to produce the catalytic filters.

The UNamur-STÛV collaboration continues today with the Win4Doc (doctorate in business) DeCOVskite project, led by PhD student Louis Garin (UNamur - CMI) and supervised by Tarek Barakat. Objectives:

• Develop a second generation of catalysts to completely reduce fine particle emissions.
• Limit the use of precious metals.
• Sustain biomass combustion and make STÛV the world leader in zero-emission stoves.

This collaboration has enabled:

• The acquisition and transfer of know-how and equipment between UNamur and STÛV to validate results under industrial conditions.
• The organization of multidisciplinary workshops, such as the one on October 14, promoting the sharing of expertise around biomass combustion and sustainable development.

At the end of October, members of UNamur and STÛV came together to take part in a workshop organized by UNamur's Research Administration and STÛV. The aim? To highlight the benefits of collaborative research between companies and universities on subjects ranging from energy, the environment, profitability, ethics and regulation to sustainable development. The two partners discussed their collaboration, expertise and development prospects.

I was fascinated by the research field of one of my professors, Guy Demortier. He was working on the characterization of antique jewelry. He had found a way to differentiate by PIXE (Proton Induced X-ray Emission) analysis between antique and modern brazes that contained Cadmium, the presence of this element in antique jewelry being controversial at the time. He was interested in ancient soldering methods in general, and the granulation technique in particular. He studied them at the Laboratoire d'Analyses par Réaction Nucléaires (LARN). Brazing is an assembly operation involving the fusion of a filler metal (e.g. copper- or silver-based) without melting the base metal. This phenomenon allows a liquid metal to penetrate first by capillary action and then by diffusion at the interface of the metals to be joined, making the junction permanent after solidification. Among the jewels of antiquity, we find brazes made with incredible precision, the ancient techniques are fascinating.

In fact, this was one of Namur's fields of research at the time: heritage sciences. Professor Demortier was conducting studies on a variety of jewels, but those made by the Etruscans using the so-called granulation technique, which first appeared in Eturia in the 8th century BC, are particularly incredible. It consists of depositing hundreds of tiny gold granules, up to two-tenths of a millimeter in diameter, on the surface to be decorated, and then soldering them onto the jewel without altering its fineness. So I also trained in brazing techniques and physical metallurgy.

I applied for a position as a physicist at CERN in the field of vacuum and thin films, but was invited for the position of head of the vacuum brazing department. This department is very important for CERN as it studies methods for assembling particularly delicate and precise parts for accelerators. It also manufactures prototypes and often one-off parts. Broadly speaking, vacuum brazing is the same technique as the one we study at Namur, except that it is carried out in a vacuum chamber. This means no oxidation, perfect wetting of the brazing alloys on the parts to be assembled, and very precise temperature control to obtain very precise assemblies (we're talking microns!). I'd never heard of vacuum brazing, but my experience of Etruscan brazing, metallurgy and my background in applied physics as taught at Namur were of particular interest to the selection committee. They hired me right away!

CERN is primarily known for hosting particle accelerators, including the famous LHC (Large Hadron Collider), a 27 km circumference accelerator buried some 100 m underground, which accelerates particles to 99.9999991% of the speed of light! CERN's research focuses on technology and innovation in many fields: nuclear physics, cosmic rays and cloud formation, antimatter research, the search for rare phenomena (such as the Higgs boson) and a contribution to neutrino research. It is also the birthplace of the World Wide Web (WWW). There are also projects in healthcare, medicine and partnerships with industry.

For my part, in addition to developing vacuum brazing methods, a field in which I've worked for over 20 years, I've worked a lot in parallel for the CLOUD experiment. For over 10 years, and until recently, I was its Technical Coordinator. CLOUD is a small but fascinating experiment at CERN which studies cloud formation and uses a particle beam to reproduce atomic bombardment in the laboratory in the manner of galactic radiation in our atmosphere. Using an ultra-clean 26 m³ cloud chamber, precise gas injection systems, electric fields, UV light systems and multiple detectors, we reproduce and study the Earth's atmosphere to understand whether galactic rays can indeed influence climate. This experiment calls on various fields of applied physics, and my background at UNamur has helped me once again.

I was also responsible for CERN's MACHINA project -Movable Accelerator for Cultural Heritage In situ Non-destructive Analysis - carried out in collaboration with the Istituto Nazionale di Fisica Nucleare (INFN), Florence section - Italy. Together, we have created the first portable proton accelerator for in-situ, non-destructive analysis in heritage science. MACHINA is soon to be used at the OPD (Opificio delle Pietre Dure), one of the oldest and most prestigious art restoration centers, also in Florence. The accelerator is also destined to travel to other museums or restoration centers.

ELISA uses the same accelerator cavity as MACHINA. The public can observe a proton beam extracted just a few centimetres from their eyes. Demonstrations are organized to show various physical phenomena, such as light production in gases or beam deflection with dipoles or quadrupoles, for example. The PIXE analysis method is also presented. ELISA is also a high-performance accelerator that we use for research projects in the field of heritage and others such as thin films, which are used extensively at CERN. The special feature is that the scientists who come to work with us do so in front of the public!

I remember that in 1989, I finished typing my report for my IRSIA fellowship in the middle of the night, the day before the deadline. It had to be in by midnight the next day. There were very few computers back then, so I typed my report at the last minute on one of the secretaries' Macs. One false move and pow! all my data was gone - big panic! The next day, the secretary helped me restore my file, we printed out the document and I dropped it straight into the mailbox in Brussels, where I arrived after 11pm, in extremis, because at midnight, someone had come to close the mailbox. Fortunately, technology has come a long way since then...

The proximity between teaching and research inspires and questions. This enables graduate students to move into multiple areas of working life.

Come and study in Namur!

Serge Mathot (May 2025) - Interview by Karin Derochette

• The CERN accelerators complex
• The Science Portal, CERN's public education and communication center
• Newsroom - June 2025 | The Departement of physics hosts a delegation from CERN
• Newsroom and Omalius Alumni article - September 2022 | François Briard