title: Monoclinic Tungsten Oxide with {100} Facet Orientation and Tuned Electronic Band Structure for Enhanced Photocatalytic Oxidations.
abstract: Exploring surface-exposed highly active crystal facets for photocatalytic oxidations is promising in utilizing monoclinic WO3 semiconductor. However, the previously reported highly active facets for monoclinic WO3 were mainly toward enhancing photocatalytic reductions. Here we report that the WO3 with {100} facet orientation and tuned surface electronic band structure can effectively enhance photocatalytic oxidation properties. The {100} faceted WO3 single crystals are synthesized via a facile hydrothermal method. The UV-visible diffuse reflectance, X-ray photoelectron spectroscopy valence band spectra, and photoelectrochemical measurements suggest that the {100} faceted WO3 has a much higher energy level of valence band maximum compared with the normal WO3 crystals without preferred orientation of the crystal face. The density functional theory calculations reveal that the shift of O 2p and W 5d states in {100} face induce a unique band structure. In comparison with the normal WO3, the {100} faceted WO3 exhibits an O2 evolution rate about 5.1 times in water splitting, and also shows an acetone evolution rate of 4.2 times as well as CO2 evolution rate of 3.8 times in gaseous degradation of 2-propanol. This study demonstrates an efficient crystal face engineering route to tune the surface electronic band structure for enhanced photocatalytic oxidations.
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.|Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.affiliation: School of Advanced Materials, Peking University Shenzhen Graduate School , University Town, Shenzhen, Guangdong 518055, China.
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Mei
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.
authors.forename: Xiaohe
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Qu
authors.affiliation: TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University , 92 Weijin Road, Nankai District, Tianjin 300072, China.
authors.forename: Yunxiang
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.
authors.forename: Siqi
authors.initials: S
authors.lastname: Li
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.
authors.forename: Weihong
authors.initials: W
authors.lastname: Qi
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University , Nanjing 211189, China.
authors.forename: Yuanjian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.|TU-NIMS Joint Research Center, School of Materials Science and Engineering, Tianjin University , 92 Weijin Road, Nankai District, Tianjin 300072, China.
authors.forename: Jinhua
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong , Tat Chee Avenue, Kowloon, Hong Kong SAR, China.
authors.forename: Vellaisamy A L
authors.initials: VA
authors.lastname: Roy
authors.affiliation: School of Materials Science and Engineering, Central South University , Changsha, Hunan 410083, China.|International Center for Materials Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS) , 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Renzhi
authors.initials: R
authors.lastname: Ma
keywords: crystal face; energy band; photocatalysis; tungsten oxide; water splitting