title: Dual Oxygen and Tungsten Vacancies on a WO3 Photoanode for Enhanced Water Oxidation.
abstract: Alleviating charge recombination at the electrode/electrolyte interface by introducing an overlayer is considered an efficient approach to improve photoelectrochemical (PEC) water oxidation. A WO3 overlayer with dual oxygen and tungsten vacancies was prepared by using a solution-based reducing agent, LEDA (lithium dissolved in ethylenediamine), which improved the PEC performance of the mesoporous WO3 photoanode dramatically. In comparison to the pristine samples, the interconnected WO3 nanoparticles surrounded by a 2-2.5 nm thick overlayer exhibited a photocurrent density approximately 2.4 times higher and a marked cathodic shift of the onset potential, which is mainly attributed to the facilitative effect on interface charge transfer and the improved conductivity by enhanced charge carrier density. This simple and effective strategy may provide a new path to improve the PEC performance of other photoanodes.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 120-749, Republic of Korea.|SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, 440-746, Republic of Korea.
authors.forename: Ming
authors.initials: M
authors.lastname: Ma
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 120-749, Republic of Korea.
authors.forename: Kan
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 120-749, Republic of Korea.|SKKU Advanced Institute of Nano Technology, Sungkyunkwan University, Suwon, 440-746, Republic of Korea.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 120-749, Republic of Korea.
authors.forename: Myung Sun
authors.initials: MS
authors.lastname: Jung
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 120-749, Republic of Korea.
authors.forename: Myung Jin
authors.initials: MJ
authors.lastname: Jeong
authors.affiliation: Department of Chemical and Biomolecular Engineering, Yonsei University, Seoul, 120-749, Republic of Korea. lutts@yonsei.ac.kr.
authors.forename: Jong Hyeok
authors.initials: JH
authors.lastname: Park
keywords: WO3; amorphous overlayers; dual vacancy; photoelectrochemical; water oxidation