Nanoparticles: Two-faced materials boost hydrogen production

Janus, the two-faced god of Roman mythology, has lent his name to two-sphere particles that can be used to boost hydrogen production.<br><br>Copyright : Kevin Richardson<br>

Hydrogen is crucial for the oil-refining industry and the production of essential chemicals such as the ammonia used in fertilizers. Since producing hydrogen is costly, scientists have long searched for alternative, energy-efficient methods to separate hydrogen atoms from abundant sources such as water.

Nanometer-scale structures consisting of cheap metal and oxide spheres were recently demonstrated as an excellent catalyst for a hydrogen-production reaction powered only by sunlight. The study was completed by Ming-Yong Han and his colleagues of the A*STAR Institute of Materials Research and Engineering, Singapore, working in collaboration with a team of researchers from Singapore and France1.
Han and his team mixed 50-nanometer diameter spheres of gold into a titanium dioxide precursor such that a sphere of titanium dioxide formed on the side of each gold nanoparticle. Structures with this two-sphere arrangement are known as Janus particles, named after the two-headed god from Roman mythology. While the Janus particles were suspended in a mixture of water and isopropyl alcohol, Han and co-workers shone visible light on them and measured hydrogen production, which proceeded at a rate as fast as 2 milliliters per minute.

The researchers then used theoretical models to show that this production rate was caused by so-called plasmonics effects: that is, the electrons on the surface of the gold nanoparticle at the junction with the titanium dioxide coupled to the incoming light and formed light–matter hybrid particles called plasmon polaritons. The energy absorbed by these particles then passed into the surrounding liquid, and this drove the hydrogen-releasing chemical reaction.

“Our work provides insight into mechanisms that will be useful for the future development of high-performance photocatalysts,” says Han. Indeed, Han and his co-workers were able to improve the efficiency of the hydrogen production even further: they increased the area of the metal–oxide interface by using larger gold nanoparticles.

The Janus particles were 100 times more efficient as a catalyst for hydrogen production than bare gold nanoparticles. Moreover, they were over one-and-a-half times better than another common type of plasmonic nanoparticle, core–shell particles, in which the oxide material forms a coating around the metal nanoparticle.

“We next hope to develop a better understanding of the processes that occur at the metal–titanium-dioxide interface using a combination of experimental observations and theoretical simulations,” says Han. “This will get us closer to our ultimate goal of using solar illumination as an abundant source of renewable energy.”

The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering

Journal information
The A*STAR-affiliated researchers contributing to this research are from the Institute of Materials Research and Engineering

Media Contact

A*STAR Research Research asia research news

All latest news from the category: Materials Sciences

Materials management deals with the research, development, manufacturing and processing of raw and industrial materials. Key aspects here are biological and medical issues, which play an increasingly important role in this field.

innovations-report offers in-depth articles related to the development and application of materials and the structure and properties of new materials.

Back to home

Comments (0)

Write a comment

Newest articles

Results for control of pollutants in water

Brazilian scientists tested a simple and sustainable method for monitoring and degrading a mixture of polycyclic aromatic hydrocarbons, compounds present in fossil fuels and industrial waste. An article published in the journal Catalysis…

A tandem approach for better solar cells

Perovskite-based solar cells were first proved in 2009 to have excellent light-absorbing properties of methylammonium lead bromide and methylammonium lead iodide, collectively referred to as lead halide perovskites or, more…

The behavior of ant queens is shaped by their social environment

Specialization of ant queens as mere egg-layers is reversible / Queen behavioral specialization is initiated and maintained by the presence of workers. The queens in colonies of social insects, such…

Partners & Sponsors