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A Blinking Mesoporous TiO 2− x Composed of Nanosized Anatase with Unusually Long‐Lived Trapped Charge Carriers
Author(s) -
Zhang Tao,
Low Jingxiang,
Yu Jiaguo,
Tyryshkin Alexei M.,
Mikmeková Eliška,
Asefa Tewodros
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202005143
Subject(s) - anatase , materials science , mesoporous material , charge carrier , rutile , nanomaterials , nanoparticle , photocatalysis , nanotechnology , chemical engineering , photochemistry , optoelectronics , catalysis , chemistry , organic chemistry , engineering
A mesoporous TiO 2− x material comprised of small, crystalline, vacancy‐rich anatase nanoparticles (NPs) shows unique optical, thermal, and electronic properties. It is synthesized using polymer‐derived mesoporous carbon (PDMC) as a template. The PDMC pores serve as physical barriers during the condensation and pyrolysis of a titania precursor, preventing the titania NPs from growing beyond 10 nm in size. Unlike most titania nanomaterials, during pyrolysis the NPs undergo no transition from the anatase to rutile phase and they become catalytically active reduced TiO 2− x . When exposed to a slow electron beam, the NPs exhibit a charge/discharge behavior, lighting up and fading away for an average period of 15 s for an extended period of time. The NPs also show a 50 nm red‐shift in their UV/Vis absorption and long‐lived charge carriers (electrons and holes) at room temperature in the dark, even long after UV irradiation. The NPs as photocatalysts show a good activity for CO 2 reduction.