Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New method can make cheaper solar energy storage

01.07.2015

Storing solar energy as hydrogen is a promising way for developing comprehensive renewable energy systems. To accomplish this, traditional solar panels can be used to generate an electrical current that splits water molecules into oxygen and hydrogen, the latter being considered a form of solar fuel.

However, the cost of producing efficient solar panels makes water-splitting technologies too expensive to commercialize. EPFL scientists have now developed a simple, unconventional method to fabricate high-quality, efficient solar panels for direct solar hydrogen production with low cost. The work is published in Nature Communications.


This is a photograph of a single-flake-layer WSe2 thin film deposited on flexible Sn:In2O3 (ITO)-coated PET plastic.

Credit: Kevin Sivula (EPFL)

Many different materials have been considered for use in direct solar-to-hydrogen conversion technologies but "2-D materials" have recently been identified as promising candidates. In general these materials--which famously include graphene--have extraordinary electronic properties.

However, harvesting usable amounts of solar energy requires large areas of solar panels, and it is notoriously difficult and expensive to fabricate thin films of 2-D materials at such a scale and maintain good performance.

Kevin Sivula and colleagues at EPFL addressed this problem with an innovative and cheap method that uses the boundary between two non-mixing liquids. The researchers focused on one of the best 2-D materials for solar water splitting, called "tungsten diselenide". Past studies have shown that this material has a great efficiency for converting solar energy directly into hydrogen fuel while also being highly stable.

Before making a thin film of it, the scientists first had to achieve an even dispersion of the material. To do this, they mixed the tungsten diselenide powder with a liquid solvent using sonic vibrations to "exfoliate" it into thin, 2-D flakes, and then added special chemicals to stabilize the mix. Developed by Sivula's lab (2014), this technique produces an even dispersion of the flakes that is similar to an ink or a paint.

The researchers then used an out-of-the-box innovation to produce high-quality thin films: they injected the tungsten diselenide ink at the boundary between two liquids that do not mix. Exploiting this oil-and-water effect, they used the interface of the two liquids as a "rolling pin" that forced the 2-D flakes to form an even and high-quality thin film with minimal clumping and restacking. The liquids were then carefully removed and the thin film was transferred to a flexible plastic support, which is much less expensive than a traditional solar panel.

The thin film produced like this was tested and found to be superior in efficiency to films made with the same material but using other comparable methods. At this proof-of-concept stage, the solar-to-hydrogen conversion efficiency was around 1%--already a vast improvement over thin films prepared by other methods, and with considerable potential for higher efficiencies in the future.

More importantly, this liquid-liquid method can be scaled up on a commercial level. "It is suitable for rapid and large-area roll-to-roll processing," says Kevin Sivula. "Considering the stability of these materials and the comparative ease of our deposition method, this represents an important advance towards economical solar-to-fuel energy conversion."

###

This work was funded by the Swiss Competence Centers for Energy Research (SCCER Heat and Electricity Storage) and the European Commission's Framework Project 7 (FP7) through a Marie-Curie Intra-European Fellowship (COCHALPEC).

Reference

Yu X, Prévot MS, Guijarro N, Sivula K. Self-assembled 2D WSe2 thin films for photoelectrochemical hydrogen production. Nature Communications 01 July 2015. DOI: 10.1038/ncomms8596

Nik Papageorgiou | EurekAlert!

More articles from Materials Sciences:

nachricht Robust and functional – surface finishing by suspension spraying
19.09.2017 | Fraunhofer-Institut für Keramische Technologien und Systeme IKTS

nachricht Graphene and other carbon nanomaterials can replace scarce metals
19.09.2017 | Chalmers University of Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

Im Focus: Silencing bacteria

HZI researchers pave the way for new agents that render hospital pathogens mute

Pathogenic bacteria are becoming resistant to common antibiotics to an ever increasing degree. One of the most difficult germs is Pseudomonas aeruginosa, a...

Im Focus: Artificial Enzymes for Hydrogen Conversion

Scientists from the MPI for Chemical Energy Conversion report in the first issue of the new journal JOULE.

Cell Press has just released the first issue of Joule, a new journal dedicated to sustainable energy research. In this issue James Birrell, Olaf Rüdiger,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Foster tadpoles trigger parental instinct in poison frogs

20.09.2017 | Life Sciences

Drones can almost see in the dark

20.09.2017 | Information Technology

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>