FEATURE Evolving Innovation in Achieving SDGs Water Gas Converting CO2 into a resource CO2 Artifi cial toward a decarbonized Photosynthesis society Renewable solar power Generating new energy 2 from sunlight, water, Changes CO and CO2 H2 Water Methanol Electricity into Energy electrolysis synthesis Solar cells Fuel can be produced by combining the hydrogen produced Dr. Akira Fujishima is the director of the from solar energy with greenhouse gases emitted by humans. International Research Center at the University of Science. He discovered photocatalysis while enrolled at the University A method to convert carbon into energy was proposed of Tokyo Graduate School. That discovery was later called the Honda–Fujishima effect, with research on arti cial photosynthesis by Dr. Akira Fujishima, the discoverer of photocatalysis. then being initiated around the world. mechanism is known as carbon climate change and the resource them.” recycling. Dr. Fujishima added, issue. At present, we must overcome The innovation of efficient carbon “The production of methane is a a number of big hurdles, and I am recycling will surely lead to the methodology to contribute to both also actively conducting research on resolution of global issues. t is not widely known that the Dr. Kenichi Honda, is able to the future.” Iglass pyramid in the courtyard produce a variety of effects using The reduction of greenhouse gases of the Louvre Museum in Paris has only light, and without using any is also a prerequisite for achieving a transparent coating that exhibits electricity. Its applications have since Sustainable Development Goals an antifouling effect upon exposure expanded to supplying antifouling (SDGs). As Prime Minister Shinzo Used Tea Leaves Found to Enhance Photoreduction to natural light; neither electricity and antifogging effects, as well as Abe stated at the World Economic nor special chemicals are required oxidation-reduction, among many Forum this year, an existing for initiating that effect. Dr. Akira others. Dr. Fujishima’s research technology of methanation to Fujishima, a Japanese researcher, regarding artificial photosynthesis, remove CO2 is getting attention anew was the first person to discover the which was concerned with extracting by creating resources through the Similar to Dr. Fujishima, a scientist polyphenol contained in tea may be photocatalysis that forms the basis hydrogen from water and using it combination of CO2 and hydrogen, who opened the door to a new world effective in the reduction of oxidized of the effect. as energy, has gained a particularly in efforts toward the realization of of science more than half a century ago, iron ions. Consequently, they observed The phenomenon of large amount of attention. a decarbonized society. several young scientists are working that photoreduction is promoted by every day making new observations that the used tea leaves. These scientists photocatalysis, announced in Dr. Fujishima says, “To achieve In consideration of that viewpoint, will lead to the future. Two such young also participated in and presented their 1967 by Dr. Fujishima along with the practical application of hydrogen Dr. Fujishima has proposed the scientists are Hisato Kizu and Hayato research at the Stockholm Junior Water production using photosynthesis, following method; first, extract Matsumoto from the Shizuoka Kita High Prize held in Sweden in August. the high efficiency of hydrogen hydrogen through water electrolysis School Science Club, who devised a Shizuoka is known as the prefecture extraction is, of course, the basic key using the electricity produced from method to effectively produce hydrogen which produces the most tea in . factor. However, the other key factors highly efficient solar cells. Next, from water by utilizing used tea leaves. Although Japanese tea is said to The two young scientists initially contain a high polyphenol content and are whether we can find a catalyst combine the extracted hydrogen with demonstrated that when iron ions are thus is good for health, used tea leaves that satisfies the remaining various the CO2 emitted from power plants used as catalysts, with the oxidation are generally discarded. However, the conditions; this includes whether and factories. Finally, synthesize of iron ions, water electrolysis occurs leaves would not be discarded if they the materials used as catalysts can methane gas, which can be used as at a voltage lower than that which were utilized as a catalyst that produces be easily obtained, whether a large an energy source. If this process is is found under normal conditions. hydrogen as an energy source in a low- Furthermore, inspired by the fact that cost and eco-friendly way. Such a day surface area photocatalyst can be realized, gases containing carbon, iron ions and green tea are used for may come in the future. “We want to Japanese high school students, Kizu (left) and Matsumoto, manufactured, and whether any such as CO2, will no longer contribute Photocatalysis acts as an antifouling and antifogging discovered that the ingredients contained in used tea dyeing fabrics, they repeated the become useful people for the world,” effect simply by the irradiation of light. It has also harmful substances are contained to the greenhouse effect. Rather, leaves can enhance the photoreduction of iron ions. experiments considering that the the two students said with a smile. been used in the covering the pyramid-shaped in the material. We are waiting for those gases will become “resources” entrance of the Louvre Museum. The glass maintains its transparent beauty by decomposing dirt. a breakthrough for those things in to replace oil and natural gas. This

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