Photocatalytic decomposition of gaseous methanol over anodized iron oxide nanotube arrays in high vacuum

Journal Article · Thu Mar 15 00:00:00 EDT 2018 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2017.11.027· OSTI ID:22805457

Ohta, Takahiro; Masegi, Hikaru; Noda, Kei ^[1]

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1. Department of Electronics and Electrical Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522 (Japan)

Highlights: • Gas phase photocatalysis over iron oxide nanotube arrays (FNAs) was investigated. • Photocatalytic methanol oxidation in high vacuum was monitored in real time. • Pt-loaded FNAs showed visible light responsive photocatalysis. • Methanol decomposition and successive proton reduction led to hydrogen production. • Differences in photocatalysis between in liquid and in high vacuum are suggesigh vacuum are suggested. - Abstract: Real-time monitoring of photocatalytic methanol decomposition over anodized iron oxide nanotube arrays (FNAs) in high vacuum was performed. Switching phenomena in the partial pressures of H{sub 2}, CO and H{sub 2}O were observed simultaneously according to the ON/OFF sequence of visible and ultraviolet light illuminations over Pt-loaded FNAs prepared with photodeposition, while no change in these gas species appeared for bare FNAs and iron foils. The absence of formaldehyde (CH{sub 2}O) in the intermediates during methanol photodecomposition suggests that Pt-loaded FNAs can possibly work as a catalyst for oxidation of CH{sub 2}O. The photoreforming of methanol to hydrogen without any external bias in Pt-loaded FNAs presumably indicate some differences in photocatalytic reaction mechanisms between in liquid and in high vacuum. The dependence of the Pt photodepositon time on gas phase photocatalysis suggests that the selective deposition of Pt cocatalyst particles on the aperture parts of the nanotubes is necessary for efficient gas phase photoreforming.

• OSTI ID: 22805457
• Journal Information: Materials Research Bulletin, Vol. 99; Other Information: Copyright (c) 2017 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
08 HYDROGEN
ANODIZATION
CARBON MONOXIDE
DECOMPOSITION
FORMALDEHYDE
HYDROGEN
HYDROGEN PRODUCTION
ILLUMINANCE
IRON
IRON OXIDES
METHANOL
NANOTUBES
OXIDATION
PARTIAL PRESSURE
PHOTOCATALYSIS
PLATINUM
PRESSURE RANGE MILLI PA
PROTONS
REACTION KINETICS
ULTRAVIOLET RADIATION