Journal
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Volume 12, Issue 3, Pages 1066-1072Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.jpclett.0c03726
Keywords
-
Categories
Funding
- National Key R&D Program of China [2018YFE0203002]
- National Natural Science Foundation of China (NSFC Center for Chemical Dynamics) [21673235]
- Strategic Priority Research Program of the Chinese Academy of Sciences [XDB17000000]
- International Partnership Program of the Chinese Academy of Sciences [121421KYSB20170012]
- Guangdong Innovative & Entrepreneurial Research Team Program [2019ZT08L455, 2019JC01X091]
- Shenzhen Science and Technology Innovation Committee [JCYJ2019080914021660]
Ask authors/readers for more resources
This study investigates the photoinduced water dissociation and desorption on a R-TiO2(110) surface at different wavelengths, revealing significant increases in the relative yield of H2O oxidation and desorption as the laser wavelength decreases. The results suggest that the energy of charge carriers plays a crucial role in these processes and challenge the widely accepted photocatalysis model of TiO2.
Understanding the microscopic mechanism of water photocatalysis on TiO2 is of great value in energy chemistry and catalysis. To date, it is still unclear how water photocatalysis occurs after the initial light absorption. Here we report the investigation of the photoinduced water dissociation and desorption on a R-TiO2(110) surface, at different wavelengths (from 250 to 330 nm), using temperature-programmed desorption and time-of-flight techniques. Primary photooxidation products, gas phase OH radicals and surface H atoms, were clearly observed at wavelengths of <= 290 nm. As the laser wavelength decreases from 290 to 250 nm, the relative yield of H2O oxidation increases significantly. Likewise, photoinduced H2O desorption was also observed in the range of 320-250 nm, and the relative yield of H2O desorption also increases with a decrease in wavelength. The strong wavelength-dependent H2O photooxidation and photodesorption suggest that the energy of charge carriers is important in these two processes. More importantly, the result raises doubt about the widely accepted photocatalysis model of TiO2 in which the excess energy of charge carriers is useless for photocatalysis. In addition, the H2O photooxidation is more likely initiated by nonthermalized holes and is accomplished on the ground state potential energy surface via a non-adiabatic decay process.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available