Scientists have made a breakthrough in improving the efficiency of the photocatalytic reaction that splits water into hydrogen, a crucial step towards a carbon-neutral future. The research team from Tohoku University, Tokyo University of Science, and Mitsubishi Materials Corporation developed a novel method using ultrafine rhodium–chromium mixed-oxide cocatalysts that can be loaded selectively onto specific regions of the photocatalyst. This breakthrough could pave the way for harnessing hydrogen as a cleaner, more abundant energy source.

Paradigm Shift in Hydrogen Production — Photocatalysis
Clean and renewable energy sources are in great demand, so it has become urgent to search for such things. Hydrogen, a clean-burning fuel made from water and sunlight that can be used for everything from transportation to heavy industry, has long been heralded as the key to carbon neutrality. Water splitting (conversion of water into hydrogen and oxygen by light illumination) is a ideal process to accomplish energy storage, but the practical application of the PS-XHS as photocatalytic materials for splitting water has been limited due to their unsatisfactory efficiency among these semiconductor candidates.
Published in Nature Scientific Reports, a new paper reveals that researchers from Tohoku University, Tokyo University of Science and Mitsubishi Materials Corporation have uncovered a scientific breakthrough with the potential to change how we utilize hydrogen as clean fuel. This made it possible to prepare ultrafine rhodium-chromium mixed-oxide cocatalysts that are unique in activating the water-splitting reaction and resistant to the back reaction between hydrogen and oxygen, overcoming conventional limitations.
Overcoming Activity-Through Facet Selective Cocatalyst Loading
What makes this approach unique, according to the researchers, is a pair of key characteristics that distinguish it from previous studies. One, cocatalyst particles are only about 1 nanometer than tradition at distinctive sizes. This small particle size is important as it results in a very large specific surface area of the cocatalyst, and therefore could dramatically increase the activity per unit weight of cocatalyst loaded.
The next important feature of the new technique was facet-selective loading of the cocatalyst on a photocatalyst. In other words, the cocatalyst is selectively loaded on deal crystal facet of the photocatalyst at which water splitting reaction occurs. Placing the cocatalyst at these hotspots makes sure that it is positioned at areas where its presence will be most efficient (Fig.
Delivering unprecedented photocatalytic activity
The findings of the study are amongst the most groundbreaking there have been. When the researchers prepared photocatalysts by this new method (the F-NCD, or facet-selective nanocrystal deposition technique), they were about 2.6 times better at photocatalytic water splitting than conventional ones.
In addition, the photocatalyst produced has the highest apparent quantum yield (a measure of how effective the process is) for strontium titanate ever recordeda popular material in photocatalysis. The success is a validation of the team’s new ideas and points to their discovery.
The Bryceland review of this research is located in the following link, and through this the authors were able to come up with a novel cocatalyst method that could be used to generate hydrogen fuel in the cleanest form yet found, taking us closer than ever before to a future where hydrogen can be created on demand with maximum efficiency for accessibly sustainable energy.