The device works stably in the laboratory and outdoors and remains efficient even with natural variations in sunlight
A research from the Brazilian Center for Research in Energy and Materials (CNPEM), in Campinas (SP), opens new perspectives for the production of green hydrogen, bringing gains in efficiency and economic viability. The study was featured prominently on the cover of the international journal ACS Energy Letters. The work resulted in a prototype device already tested in laboratory and outdoor environments, which adopts an unprecedented modular strategy to directly use solar energy, making the process cleaner and safer.
The prototype has the potential to transform the low-carbon hydrogen production chain. Today, this sustainable fuel is still expensive because its production depends on the water electrolysis process powered by the conventional electricity grid, an expensive energy source that sometimes comes from non-renewable sources, such as thermoelectric plants. The idea of electrolyzing water directly from solar energy is the ideal alternative, as it is clean, abundant and cheap, but the efficiency limitations of the photoreactor components prevent its practical application. CNPEM’s research aims to overcome this impasse by
developing innovative semiconductors capable of converting solar energy directly into hydrogen efficiently and at low cost, which could make large-scale production viable.
Led by researcher Flávio Souza, from the Brazilian Nanotechnology National Laboratory (LNNano/CNPEM), the team developed plates called photoelectrodes, made of iron oxide (hematite), an abundant and low-cost material. To increase performance, scientists added small amounts of aluminum and zirconium, which act as reinforcements, helping the material better utilize sunlight.
These plates were produced in 100 identical units and installed in modular reactors created by 3D printing. The system works like a set of building blocks, allowing for the expansion of the production scale in a practical and organized way.
The devices operated in a stable way for more than 120 hours in a row in the laboratory. When tested outdoors, on the CNPEM campus in Campinas, they also maintained the efficiency observed in the laboratory even with natural variations in sunlight.
According to Flávio Souza, “this study shows that it is possible to transform laboratory results into modular and stable systems, bringing solar hydrogen production closer to real-world applications and with the possibility of large-scale production.”
Another important point was environmental safety, as analyses showed that the release of substances during operation was below the limits permitted by regulatory bodies.
Next steps
The research marks the beginning of a new line of action by CNPEM to develop low-carbon hydrogen production solutions. Now, scientists will also have the support of the Brazilian Biorenewables National Laboratory (LNBR/CNPEM) to study the economic viability of this technology and possible areas of application.
The work also involved researchers from UFABC, Unicamp and USP, with support from CAPES, CNPq, Fapesp and Shell, in addition to strategic support from the Brazilian National Agency for Petroleum, Natural Gas and Biofuels (ANP).
The full article can be accessed at: https://pubs.acs.org/doi/10.1021/acsenergylett.5c02340.
About CNPEM
The Brazilian Center for Research in Energy and Materials (CNPEM) houses a cutting-edge, multi-user and multidisciplinary scientific environment, with actions in different areas of the National Science, Technology and Innovation System. A Social Organization supervised by the Ministry of Science, Technology and Innovation (MCTI), CNPEM is driven by research that impacts the areas of health, energy, renewable materials and sustainability. Responsible for Sirius, the largest scientific equipment ever built in the country, CNPEM currently develops the Orion project, a laboratory complex for advanced research on pathogens. Highly specialized science and engineering teams, sophisticated infrastructures open to the scientific community, strategic lines of investigation, innovative projects with the
productive sector and training of researchers and students constitute the pillars of this unique center in the country, capable of acting as a bridge between knowledge and innovation. The CNPEM is responsible for the operation of the Brazilian Synchrotron Light Laboratory (LNLS), the Brazilian Biosciences National Laboratory (LNBio), the Brazilian Nanotechnology National Laboratory (LNNano) and the Brazilian Biorenewables National Laboratory (LNBR), as well as for the Ilum School of Science, a bachelor’s degree course in Science and Technology, supported by the Ministry of Education (MEC). https://cnpem.br/
