Harvesting sunlight, researchers of the Center for Integrated Nanostructure Physics, within the Institute for Basic Science (IBS, South Korea) published in Materials Today a new strategy to transform carbon dioxide (CO2) into oxygen (O2) and pure carbon monoxide (CO) without side-products in water. This artificial photosynthesis method could bring new solutions to environmental pollution and global warming.

While, in green plants, photosynthesis fixes CO2 into sugars, the artificial photosynthesis reported in this study can convert CO2 into oxygen and pure CO as output. The latter can then be employed for a broad range of applications in electronics, semiconductor, pharmaceutical, and chemical industries. The key is to find the right high-performance photocatalyst to help the photosynthesis take place by absorbing light, convert CO2, and ensuring an efficient flow of electrons, which is essential for the entire system.

Titanium oxide (TiO2) is a well-known photocatalyst. It has already attracted significant attention in the fields of solar energy conversion and environmental protection due to its high reactivity, low toxicity, chemical stability, and low cost. While conventional TiO2 can absorb only UV light, the IBS research team reported previously two different types of blue-colored TiO2 (or “blue titania”) nanoparticles that could absorb visible light thanks to a reduced bandgap of about 2.7 eV. They were made of ordered anatase/disordered rutile (Ao/Rd) TiO2 (called, HYL’s blue TiO2-I) (Energy & Environmental Science, 2016), and disordered anatase/ordered rutile (Ad/Ro) TiO2 (called, HYL’s blue TiO2-II) (ACS Applied Materials & Interfaces, 2019), where anatase and rutile refer to two crystalline forms of TiO2 and the introduction of irregularities (disorder) in the crystal enhances the absorption of visible and infra-red light.

Read more at Institute for Basic Science

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