1. Photocatalytic reduction of Cr(VI) by Bi2.15WO6 complexed with polydopamine: Contribution of the ligand-to-metal charge transfer path.
- Author
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Ren, Hai-Tao, Jing, Meng-Zhen, Li, Da-Shuai, Li, Ting-Ting, Lou, Ching-Wen, Lin, Jia-Horng, and Han, Xu
- Subjects
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FOURIER transform infrared spectroscopy , *CHARGE transfer , *X-ray photoelectron spectroscopy , *VISIBLE spectra , *PHOTOREDUCTION - Abstract
[Display omitted] Photocatalytic reduction of Cr(VI) in water environments attracts more attention; however, the mechanisms involved in this process have not been clearly elucidated yet. In this study, the photocatalytic reduction of Cr(VI) by polydopamine modified Bi 2.15 WO 6 (PDA/BWO) under visible light was conducted. Kinetics results show that PDA apparently accelerates the reduction of Cr(VI). The quasi-first-order kinetic constant of Cr(VI) reduction by 5PDA/BWO is 70.0 times that of the original BWO, reaching 0.070 min−1. X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Raman analyses confirm the formation of ligand-to-metal charge transfer (LMCT) complex [Bi(III) O C] between PDA and BWO. The formed Bi(III) O C complex enhances visible light response and narrows the bandgap of PDA/BWO. The photoelectrochemical and photoluminescent characterization further reveals that the formed Bi(III) O C complex inhibits the recombination of carriers, thus enhancing the photocatalytic reactivity of PDA/BWO. Electrons, are derived from three paths, including dye sensitization, LMCT and bandgap excitation, contribute to Cr(VI) reduction by PDA/BWO. This study provides new insights on the paths of Cr(VI) reduction by PDA/BWO under visible light. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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