title: Highly efficient low-temperature plasma-assisted modification of TiO2 nanosheets with exposed {001} facets for enhanced visible-light photocatalytic activity.
abstract: Anatase TiO2 nanosheets with exposed {001} facets have been controllably modified under non-thermal dielectric barrier discharge (DBD) plasma with various working gas, including Ar, H2 , and NH3 . The obtained TiO2 nanosheets possess a unique crystalline core/amorphous shell structure (TiO2 @TiO2-x ), which exhibit the improved visible and near-infrared light absorption. The types of dopants (oxygen vacancy/surface Ti(3+) /substituted N) in oxygen-deficient TiO2 can be tuned by controlling the working gases during plasma discharge. Both surface Ti(3+) and substituted N were doped into the lattice of TiO2 through NH3 plasma discharge, whereas the oxygen vacancy or Ti(3+) (along with the oxygen vacancy) was obtained after Ar or H2 plasma treatment. The TiO2 @TiO2-x from NH3 plasma with a green color shows the highest photocatalytic activity under visible-light irradiation compared with the products from Ar plasma or H2 plasma due to the synergistic effect of reduction and simultaneous nitridation in the NH3 plasma.
authors.affiliation: Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116023 (P.R. China).
authors.forename: Beibei
authors.initials: B
authors.lastname: Li
authors.forename: Zongbin
authors.initials: Z
authors.lastname: Zhao
authors.forename: Quan
authors.initials: Q
authors.lastname: Zhou
authors.forename: Bo
authors.initials: B
authors.lastname: Meng
authors.forename: Xiangtong
authors.initials: X
authors.lastname: Meng
authors.forename: Jieshan
authors.initials: J
authors.lastname: Qiu
keywords: UV/Vis spectroscopy; doping; nanosheets; photochemistry; plasma chemistry; titanium