The production of green hydrogen is set to play an increasingly important role in the future energy system, offering a nearly climate-neutral way to store chemical energy and produce climate-friendly fuels. However, one of the bottlenecks in this process is the oxygen evolution reaction (OER), which requires special catalysts to speed up the formation of hydrogen and oxygen at the electrodes.

Current catalysts are made from precious metals, but these are rare and expensive, limiting their use for large-scale industrial applications. Researchers at the Helmholtz-Zentrum Berlin (HZB) have now identified a promising alternative: MXene structures that can host catalytically active particles to enhance the oxygen evolution reaction.

MXenes are flaky structures made of carbon and transition metals, which can be used as carriers for embedding catalytically active particles. A team led by Michelle Browne at HZB has developed sophisticated variants of these materials, using different vanadium carbide MXene variants as the basis for their research.

One variant, V2CTx with 10% vanadium vacancies, was found to have a significantly larger internal surface area than the pure MXene. This structure was then embedded with Co0.66Fe0.34 catalyst particles using a multi-step chemical process in Michelle Browne’s laboratory at HZB.

The resulting material showed a significant enhancement in catalytic activity compared to the pure iron-cobalt compound, and further improved efficiency when used as a carrier for the catalytically active particles. The team was able to track changes in the oxidation numbers of cobalt and iron during the electrolytic reaction using in situ X-ray absorption spectroscopy at the SOLEIL synchrotron source.

The results provide initial insights into the complex interplay between the carrier structure, the embedding of catalytically active particles, and catalytic activity. MXene is a promising candidate for the development of innovative, highly efficient, and inexpensive catalysts, and its use as a carrier material could revolutionize the production of green hydrogen.

As Michelle Browne emphasizes, “Currently, the industry has not yet considered MXene as a carrier material for catalytically active particles on the radar. We are conducting basic research here, but with clear prospects: on applications.” The study’s first author, Can Kaplan, adds that their results make the technology really meaningful and interesting for industrial applications.

The potential of MXene catalysts to accelerate the oxygen evolution reaction and boost green hydrogen production is a promising path forward in the energy transition. With further research and development, these materials could play a crucial role in making green hydrogen more viable and cost-effective, ultimately contributing to a more sustainable energy future.

Chronic renal failure affects millions worldwide, including four million Canadians. Researchers at the Canadian hospital research centre, CRCHUM, have made a world-first breakthrough by identifying microRNA that can protect small blood vessels and support kidney function after severe injury. This advancement has significant implications for early diagnosis and prevention of the disease.

Previously, there was no reliable biomarker to evaluate the health of tiny capillaries in the kidneys or develop targeted approaches to preserve kidney function. A study published in JCI Insight reveals that miR-423-5p microRNA is a promising marker in the blood for predicting the microvascular health of the kidneys.

Researchers Marie-Josée Hébert and Héloïse Cardinal, along with Francis Migneault, have been studying the loss of peritubular capillaries, a conclusive indicator of chronic renal failure. These tiny blood vessels filter waste products out of the blood and transport oxygen and nutrients necessary for the organ’s functions.

Kidney injuries can lead to a decrease in small blood vessels, seriously disrupting kidney function. In people who have received a transplant, if kidney function is severely altered, the kidney’s survival is threatened. Using this biomarker, a test could be developed to evaluate the status of small blood vessels much earlier. Doctors could then better assess microvascular health in higher-risk patients.

This breakthrough has been confirmed in 51 transplant recipients and has shown potential for preventing further damage to kidneys. The researchers are now focused on alternative techniques to transport microRNA or a cocktail to the kidney, which may be useful for other patients with cardiac failure, pulmonary failure, or certain neurodegenerative diseases.

The discovery of miR-423-5p microRNA could have a significant impact on the health of Canadians and potentially lead to new treatments for various medical conditions. Researchers are currently exploring its potential in other areas, such as determining if existing medications impact small blood vessel health in kidney transplant patients.

The human body has a clever way of defending itself against bacterial pathogens by depriving them of vital nutrients like iron. This strategy, however, doesn’t always work against Salmonella, a bacterium responsible for typhoid fever. Researchers at the University of Basel have made an important discovery that sheds light on how these bacteria evade the immune system.

In a study published in Cell Host & Microbe, Professor Dirk Bumann’s team found that Salmonella specifically targets iron-rich regions within immune cells to replicate. This means that instead of being starved out by iron deprivation, the bacteria find a way to tap into the available iron and continue growing.

The body uses the transport protein NRAMP1 to pump iron out of the bacteria’s hiding place in immune cells. However, Salmonella has found a way to circumvent this strategy by infecting macrophages that reside in areas rich in red blood cell remnants. These macrophages contain high levels of iron, which the bacteria exploit to keep growing.

The researchers analyzed single-cell populations and discovered two distinct groups of Salmonella within these macrophages. One group resides in iron-poor regions and struggles to survive, while another subset thrives in vesicles rich in red blood cell remnants, where NRAMP1 transporters remove excess iron for recycling.

Even with over 99% of the iron being pumped out, the small remaining amount is still enough for the bacteria to keep growing. This finding highlights the importance of studying infections at the single-cell level and understanding how pathogens adapt and evade the immune defense mechanism.

The discovery provides important insights into host-pathogen dynamics and emphasizes the need to find effective ways to combat infections. By understanding how Salmonella outsmarts the immune system, researchers can develop new strategies to prevent and treat typhoid fever and other bacterial diseases.