This research was published in Scientific Reports, a science journal published by the Nature Publishing Group. (Title: “Single-crystalline, wormlike hematite photoanodes for efficient solar water splitting”) on 17 September 2013).
Schematic Diagram of PEC cell with wormlike hematite photoanode
Copyright : UNIST
The previous record of solar hydrogen efficiency among stable oxide semiconductor photoanodes was 4.2% owned by the research group of Prof. Michael Graetzel at the Ecole Polytechnique de Lausanne (EPFL), Switzerland.
Solar water splitting is a renewable and sustainable energy production method because it can utilize sunlight, the most abundant energy source on earth, and water, the most abundant natural resource on earth. At the moment, low solar-to-hydrogen conversion efficiency is the most serious hurdle to overcome in the commercialization of this technology.
The key to the solar water splitting technology is the semiconductor photocatalysts that absorb sunlight and split water to hydrogen and oxygen using the absorbed solar energy. Hematite, an iron oxide (the rust of iron, Fe2O3) absorbs an ample amount of sunlight. It has also excellent stability in water, a low price, and environmentally benign characteristics.
Thus it has been a most popular and promising candidate of photoanode material for solar water splitting over the last two decades. However, hematite has a major and critical drawback of an extremely poor electrical conducting property. Thus most of the hematite anodes have exhibited very low performance.
Prof. Jae Sung Lee of UNIST led the joint research with Prof. Kazunari Domen’s group at the University of Tokyo, Japan, developing new anode material which has outstanding hydrogen production efficiency.
Prof. Lee and coworkers employed a series of modifications to improve the property of hematite. First, a unique single-crystalline “wormlike” morphology was produced by using a nanomaterial synthesis technique. Second, a small amount of platinum was introduced into the hematite lattice as doping. Finally, a cobalt catalyst was employed to help oxygen evolution reaction. These modifications reduced energy loss due to charge recombination and brought the record-breaking solar-to-hydrogen conversion efficiency.
“The efficiency of 10% is needed for practical application of solar water splitting technology. There is still long way to reach that level. Yet, our work has made an important milestone by exceeding 5% level, which has been a psychological barrier in this field,” said Prof. Lee. “It has also demonstrated that the carefully designed fabrication and modification strategies are effective to obtain highly efficient photocatalysts and hopefully could lead to our final goal of 10% solar-to-hydrogen efficiency in a near future.”
The fellow researchers include Jae Young Kim from UNIST who performed most of the experiments oscillating between two laboratories in Ulsan and Tokyo, and researchers from POSTECH and the University of Tokyo.
This research was sponsored by the A3 Foresight Program of the Korean National Research Foundation which supports international collaboration projects between three Asian countries of Korea, China and Japan.
Homepage of Jae Sung Lee http://ecocat.unist.ac.kr
Ulsan National Institute of Science and Technology (UNIST) http://www.unist.ac.krThe original press release
Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University
TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy