A team under Ajou's Professor In Sun Cho develops nano material technology that raises efficiency of hydrogen production

2015-09-15

A team led by Ajou University's Professor In Sun Cho (Department of Materials Science and Engineering, pictured above) developed nano material manufacturing technology that will significantly raise the efficiency of hydrogen production through solar cells.

The research was conducted with the support for essential research projects carried out by the National Research Foundation of Korea, and its findings were published in the August 18th issue of The Nano Letters, a renowned academic journal in the field of nano-technology, under the title of "Highly Efficient Solar Water Splitting from Transferred TiO2 Nanotube Arrays."

Professor Cho said that he joined hands with Professor Jong Hyeok Park (Yonsei University) and Professor Tai Ho Park (Pohang University of Science and Technology) to develop nano material manufacturing technology that will significantly raise sunlight absorption and electricity conductivity by using TiO2, a photocatalyst.

The research will increase the efficiency of hydrogen production through solar-cell-based water splitting to the highest theoretical level. The technology allows for hydrogen production by splitting water with semi-conductor materials and solar cells. While hydrogen energy is drawing attention as a clean energy of the future, the technological production efficiency should be at least 10 percent for it to be commercialized.

However, there has been difficulty in raising hydrogen production efficiency via solar cells, because titanium oxide (TiO2), tungsten oxide (WO), or bismuth vanadium oxide (BiVO), that are used as an oxidation photoelectrode have low efficiency.

In order to address this issue, the research team created titanium oxide nanotube material by making a nanotube structure from titanium oxide material and applying dual reduction procedures that combine chemical and flame reductions.

Professor Cho said, "The highly efficient nano material technology based on chemical and flame reductions can be applied to tungsten oxide, iron oxide, and bismuth vanadium oxide, etc. as well as those based on titanium oxide," adding, "These materials are very high in theoretical efficiency levels, and I believe that the 10 percent efficiency limit can be surpassed through additional research and development.

The research by Professor Cho's team can expand applications of titanium oxide materials that are being used in many products including cosmetics and paint. In addition, the findings are expected to considerably increase the chances of commercializing solar-cell-based hydrogen reduction technology. The commercialization is predicted to come within the next ten years. 

 < Diagram of titanium oxide transfer coating on nanotube, and the technological process of chemical and flame reductions >