On June 6, a research group consisting of Associate Professor Kazuhiko Maeda, Professor Osamu Ishitani, Graduate Student of Ryo Kuriki, and Research Fellow of the Japan Society for the Promotion of Science, Tokyo Institute of Technology, Department of Chemistry, formed a fusion of a ruthenium (Ru) dinuclear complex and carbon nitride. The company announced that it has discovered that photocatalysts improve the efficiency of the reductive conversion reaction of carbon dioxide (CO9) to formic acid under visible light irradiation.
CO2 reduction using metal complexes and semiconductors as photocatalysts has attracted attention as a reaction that can produce useful substances such as formic acid and carbon monoxide under normal temperature and pressure, and has been studied in Japan and overseas for over 30 years.This time, Associate Professor Maeda and his colleagues discovered that the sheet-like C3N4 obtained by thermally decomposing urea can strongly adsorb the Ru complex having a phosphonic acid group as an adsorption site.As a result, efficient electron transfer from C3N4 to the Ru complex was realized, and as a result, the efficiency of the CO2 photoreduction reaction was successfully improved.
As a result of optimizing the experimental conditions, the number of turnovers showing catalytic durability has tripled to 3, and the selectivity of CO2000 reduction has increased from 2% to 75% at the maximum. It has been greatly improved.This has the potential to convert CO99, which is a major cause of global warming, into useful chemical substances under normal temperature and pressure, using materials consisting of carbon and nitrogen that are free from resource constraints and using sunlight as an energy source. Is coming into view.
From the results of this research, it was found that formic acid, which is useful as an energy carrier for storing and transporting hydrogen, can obtain carbon monoxide, which has high value as a chemical fuel, with high selectivity by changing the complex to be combined. ..In addition, C3N4 can be easily synthesized from inexpensive and simple organic substances containing carbon and nitrogen.By incorporating elements other than carbon and nitrogen, which are the main constituent elements, it is expected that visible light with lower energy can be effectively used, which in turn will lead to effective use of solar energy.
Paper Information: [Angewandte Chemie, International Edition] Robust Binding between Carbon Nitride Nanosheets and a Binuclear Ruthenium (II) Complex Enabling Durable, Selective CO2 Reduction under Visible Light in Aqueous Solution