A new lead-free Sillén–Aurivillius oxychloride Bi5SrTi3O14Cl with triple-perovskite layers for photocatalytic water splitting under visible light
| Autor: | Hajime Suzuki, Daichi Ozaki, Hiroshi Kageyama, Osamu Tomita, Ryu Abe, Kouichi Nakashima, Yoshiyuki Inaguma |
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| Rok vydání: | 2021 |
| Předmět: |
Valence (chemistry)
biology Band gap Chemistry General Chemical Engineering General Physics and Astronomy 02 engineering and technology General Chemistry Crystal structure 010402 general chemistry 021001 nanoscience & nanotechnology biology.organism_classification 01 natural sciences 0104 chemical sciences Aurivillius Crystallography Scanning transmission electron microscopy Water splitting 0210 nano-technology Photocatalytic water splitting Visible spectrum |
| Zdroj: | Journal of Photochemistry and Photobiology A: Chemistry. 408:113095 |
| ISSN: | 1010-6030 |
| Popis: | A series of Sillen–Aurivillius layered oxyhalides with a single- and double-perovskite layer, Bi4MO8X (M = Nb, Ta; X = Cl, Br) and AA′Bi3M2O11Cl (A, A′ = Sr, Ba, Pb, Bi; M = Ti, Nb, Ta), have been recently demonstrated as promising photocatalysts for visible-light-induced water splitting due to relatively high energy valence bands arising from strong interactions between Bi-6s and O-2p orbitals. Herein, we report the synthesis, characterization and photocatalytic property of Bi5SrTi3O14Cl with triple-perovskite layers. The combined use of synchrotron X-ray diffraction and scanning transmission electron microscopy allowed the precise determination of the crystal structure (space group: P2an), including site occupancies. The experimental results revealed that Bi5SrTi3O14Cl possesses a similar bandgap and valence band level as the previously reported Bi5PbTi3O14Cl, indicating that the presence of Pb-6s is not essential for the formation of a higher energy valence band maximum. Partial density of states for both materials obtained by DFT calculations suggested considerable interactions of the Bi-6s orbitals with the O-2p orbitals, in particular those in the perovskite layers, which is the key to the formation of the higher energy valence band. Bi5SrTi3O14Cl exhibited higher activity for O2 evolution than Bi5PbTi3O14Cl, suggesting the detrimental effect of Pb2+ on the photocatalytic activity, thereby allowing the construction of a Z-scheme water splitting system workable under visible light. |
| Databáze: | OpenAIRE |
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