Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Water splitting observed on the nanometer scale

05.03.2020

Whether as a fuel or in energy storage: hydrogen is being traded as the energy carrier of the future. To date, existing methodologies have not been able to elucidate how exactly the electrochemical process of water splitting into hydrogen and oxygen takes place at the molecular scale on a catalyst surface. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now developed a new method to investigate such processes "live" on the nanometer scale. The new detailed insights into the splitting of water on gold surfaces could aid the design of energy-efficient electro-catalysts.

It is a well-known school experiment: When a voltage is applied between two electrodes inserted in water, molecular hydrogen and oxygen are produced. To further the industrial use of this process, it is indispensable to make water splitting as energy-efficient as possible.


At rough areas of a catalyst surface, water is split into hydrogen and oxygen in a more energy efficient way than at smooth areas.

MPI-P, License CC-BY-SA

In addition to the material of the electrode, its surface quality is a crucial aspect for the splitting efficiency. In particular, rough spots of only few nanometers - i.e. millionths of a millimeter – in size that are called reactive centers determine the electrochemical reactivity of an electrode.

Previous investigation methods were not accurate enough to follow chemical reactions taking place at such reactive centers on the electrode surface with sufficient spatial resolution under real operating conditions, i.e. in electrolyte solution at room temperature and with an applied voltage.

A team of scientists led by Dr. Katrin Domke, independent Boehringer Ingelheim "Plus 3" group leader at the MPI-P, has now developed a new method with which the initial steps electrocatalytic water splitting on a gold surface could be studied for the first time with a spatial resolution of less than 10 nm under operating conditions.

"We were able to show experimentally that surfaces with protrusions in the nanometer range split water in a more energy efficient way than flat surfaces," says Katrin Domke. "With our images, we can follow the catalytic activity of the reactive centers during the initial steps of water splitting".

For their method, they have combined different techniques: In Raman spectroscopy, molecules are illuminated with light that they scatter. The scattered light spectrum contains information that provides a chemical fingerprint of the molecule, enabling the identification of chemical species.

However, Raman spectroscopy is typically a technique that produces only very weak and, moreover, only spatially averaged signals over hundreds or thousands of nanometers.

For this reason, the researchers have combined the Raman technique with scanning tunneling microscopy: by scanning a nanometer-thin gold tip illuminated with laser light over the surface under investigation, the Raman signal is amplified by many orders of magnitude directly at the tip apex that acts like an antenna.

This strong enhancement effect enables the investigation of very few molecules at a time. Furthermore, the tight focusing of the light by the tip leads to a spatial optical resolution of less than ten nanometer. The distinctive feature of the apparatus is that it can be operated under realistic electrocatalytic operating conditions.

"We were able to show that during water splitting at nanometer rough spots - i.e. a reactive centers - two different gold oxides are formed, which could represent important intermediates in the separation of the oxygen atom from the hydrogen atoms," says Domke. With their investigations, it is now possible to gain a more precise insight into the processes taking place on the nanometer scale on reactive surfaces and facilitate the design of more efficient electrocatalysts in the future, where less energy is needed to split water into hydrogen and oxygen.

The scientists have published their results in the renowned journal "Nature Communications".

Wissenschaftliche Ansprechpartner:

Dr. Katrin F. Domke
Email: domke@mpip-mainz.mpg.de
Tel.: 06131 379-476

Originalpublikation:

https://www.nature.com/articles/s41467-019-13692-3
DOI: 10.1038/s41467-019-13692-3

Dr. Christian Schneider | Max-Planck-Institut für Polymerforschung
Further information:
http://www.mpip-mainz.mpg.de

More articles from Life Sciences:

nachricht Human skin is an important source of ammonia emissions
27.05.2020 | Max-Planck-Institut für Chemie

nachricht Biotechnology: Triggered by light, a novel way to switch on an enzyme
27.05.2020 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Skoltech scientists get a sneak peek of a key process in battery 'life'

28.05.2020 | Power and Electrical Engineering

Elucidation of nanostructures in practical heterogeneous catalysts

28.05.2020 | Physics and Astronomy

Multifunctional e-glasses monitor health, protect eyes, control video game

28.05.2020 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>