TY - JOUR
T1 - Real-time monitoring of photocatalytic methanol decomposition over Cu2O-loaded TiO2nanotube arrays in high vacuum
AU - Masegi, Hikaru
AU - Goto, Hayato
AU - Sadale, Shivaji B.
AU - Noda, Kei
N1 - Funding Information:
This study was partly supported by a Grant-in-Aid for Scientific Research (KAKENHI No. 17K18886) of the Japan Society for the Promotion of Science (JSPS).
Publisher Copyright:
© 2020 Author(s).
PY - 2020/9/1
Y1 - 2020/9/1
N2 - We report a real-time investigation on the photocatalytic decomposition of methanol over Cu2O-loaded TiO2 nanotube arrays (TNAs) in high vacuum. Cu2O-loaded TNAs were fabricated using all-electrochemical processes. TNAs were prepared by anodizing Ti foils, and Cu2O nanoparticles (CNPs) were pulse-electrodeposited onto anodized TNA surfaces. The photocatalytic decomposition of methanol was monitored using a quadrupole mass analyzer in high vacuum, where the partial pressures of intermediate and final reaction products were measured. Switching phenomena in the partial pressures of hydrogen (H2), formaldehyde (CH2O), water (H2O), and carbon monoxide (CO) were observed simultaneously according to the ON/OFF sequence of ultraviolet irradiations over TNA/CNP composites, thereby revealing that Cu2O can facilitate proton reduction like noble-metal-based cocatalysts such as platinum, even in a high vacuum environment. The intermediate reaction products suggest that the photocatalytic oxidation of gaseous methanol over TNA/CNP proceeds under the coexistence of direct and indirect hole transfer mechanisms.
AB - We report a real-time investigation on the photocatalytic decomposition of methanol over Cu2O-loaded TiO2 nanotube arrays (TNAs) in high vacuum. Cu2O-loaded TNAs were fabricated using all-electrochemical processes. TNAs were prepared by anodizing Ti foils, and Cu2O nanoparticles (CNPs) were pulse-electrodeposited onto anodized TNA surfaces. The photocatalytic decomposition of methanol was monitored using a quadrupole mass analyzer in high vacuum, where the partial pressures of intermediate and final reaction products were measured. Switching phenomena in the partial pressures of hydrogen (H2), formaldehyde (CH2O), water (H2O), and carbon monoxide (CO) were observed simultaneously according to the ON/OFF sequence of ultraviolet irradiations over TNA/CNP composites, thereby revealing that Cu2O can facilitate proton reduction like noble-metal-based cocatalysts such as platinum, even in a high vacuum environment. The intermediate reaction products suggest that the photocatalytic oxidation of gaseous methanol over TNA/CNP proceeds under the coexistence of direct and indirect hole transfer mechanisms.
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U2 - 10.1116/6.0000194
DO - 10.1116/6.0000194
M3 - Article
AN - SCOPUS:85091822762
VL - 38
JO - Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics
JF - Journal of Vacuum Science and Technology B:Nanotechnology and Microelectronics
SN - 2166-2746
IS - 5
M1 - 052401
ER -