Direct Observation of Ethanol Photocatalysis on Rutile TiO2(110) Surface

Photocatalytic dissociation of ethanol molecules on the rutile TiO2(110) surface after UV irradiation has been investigated by scanning tunneling microscope at 80 K. Most of the ethanol molecules adsorb molecularly at Ti sites, similar to the case of methanol. After UV irradiation, two different protrusions of products were observed, one of them has been identified by the technique of tip manipulation, which was likely composed of an acetaldehyde in the middle and two bridge-bonded hydroxyls on both neighbored oxygen sites. Multi-time irradiation experiments have also been performed to further understand the relationship between the two protrusions and the process of ethanol photocatalytic dissociation. These results provide detailed insights into the photocatalysis of ethanol on rutile TiO2(110), which would help us to understand how phtotocatalytic reactions of ethnaol proceed at the fundamental level.