Green solutions with diamond materials:
Sunlight activates the catalytic behavior of diamond materials, thus helping to convert carbon dioxide into fine chemicals and fuels. © T.Petit/H.Cords/HZB
Horizon 2020 invests 3.9 million Euro in research project to convert CO2 into fuels using sunlight and diamond materials
A great new idea is now being investigated by scientists of Germany, France, England, and Sweden, among them HZB’s Prof. Emad Aziz. They propose exploring diamond materials for photocatalytic conversion of carbon dioxide into fine chemicals and fuels using visible light (DIACAT).
Their proposal was ranked top in a tough selection process within the Future Emerging Technologies (FET) Section of the European Horizon 2020 Framework Programme for Research and Innovation. It will be funded with a total budget of 3.9 million Euro, 526,000 Euro of which will be allocated to the HZB. The scientists propose to develop a novel technique for direct photocatalytic conversion of carbon dioxide into fine chemicals and fuels using visible light. Their ultimate goal is to build a functioning lab-scale device.
Diamonds and light can speed up chemical reactions
Their approach is based on a unique property of man-made diamond materials: these materials can act as a catalyst when illuminated by light. The project will be coordinated by Prof. Anke Krüger, at Julius-Maximilians-Universität Würzburg, and includes science teams from CEA (France), University of Oxford (UK), Uppsala University (Sweden), Fraunhofer Institute for Applied Solid State Physics, Ionic Liquid Technologies GmbH, and HZB in Germany.
Unique equipment at BESSY II, HZB
HZB scientist Emad Aziz has built up a research team following a Starting Grant awarded by the European Research Council in 2011. He has set up a unique instrument at HZB’s BESSY II synchrotron to analyze liquids and materials in solution and is also leading a Joint Lab at Freie Universität Berlin equipped with high-performance lasers with ultrashort pulses. “We have direct access to a multitude of experimental instruments that will enable us to investigate the physical and chemical properties of diamond materials”, he says. Postdoc Tristan Petit has brought his expertise on nanodiamonds to the HZB team: “My postdoc work was focused on nanodiamonds in solution. Now we will extend this work to bulk diamond-liquid interfaces and nanostructured diamond surfaces and see how well we can tune these materials to turn sunlight into fuel”, he explains.
Storing solar energy in chemicals
The research project will not only enhance the experimental and theoretical understanding of catalytic behavior of diamond materials, but might also result in a first device using diamond materials that demonstrates the feasibility of direct CO2 reduction using visible light. If the scientists can achieve their ambitious goals, their project might pave the way for a novel technique to store solar energy via sustainable production of fine chemicals and fuels.
- CIGS-perovskite tandem cell achieves record efficiency of 25.5 %A Berlin-based team from HZB and Center for the Science of Materials Berlin (CSMB) at the Humboldt-Universität zu Berlin has set a new record for a tandem solar cell. Using a combination of a CIGS semiconductor layer and perovskite, along with several optimised intermediate layers, they were able to convert 25.5% of sunlight into electrical energy. The previous record for this combination of materials and this size of cell stood at 24.6%. The new record has been certified and is visible in the prestigious Solar Cell Efficiency Tables (the "Green Tables"), which serve as the definitive ledger for the global photovoltaic community.
- Disorder creates new properties in compound semiconductorsAn international research team has demonstrated that the intrinsic disorder of the compound semiconductor CuInSnS₄ can be exploited to influence its optical properties. While the atomic vibrations also sense the local disorder, their response is averaged over many different local environments and therefore appear isotropic, as expected for a cubic crystal. In contrast, the optical excitations, known as excitons, are much more sensitive to the local arrangement of atoms. Surprisingly, they show a direction-dependent optical response even though the average crystal structure is cubic. These findings shed new light on the relationship between disorder and material properties, opening up new options for targeted 'disorder engineering' in optoelectronic and photocatalytic devices.
- Perovskite solar cells: Predictions of long-term stabilityReliable statements about the long-term stability of perovskite solar cells are still difficult to make. However, a new study by Dr Carolin Ulbrich’s team, published in the renowned journal Joule, highlights which methods are useful for this purpose and identifies areas where further research is needed.