Design and development of a visible light harvesting Ni–Zn/Cr–CO32− LDH system for hydrogen evolution
| Autor: | N. Baliarsingh, Lagnamayee Mohapatra, Kulamani Parida |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Hydrotalcite
Hydrogen Renewable Energy Sustainability and the Environment Brucite Chemistry Analytical chemistry chemistry.chemical_element General Chemistry engineering.material Photochemistry engineering Photocatalysis General Materials Science Atomic ratio Fourier transform infrared spectroscopy Powder diffraction Visible spectrum |
| Zdroj: | Journal of Materials Chemistry A. 1:4236 |
| ISSN: | 2050-7496 2050-7488 |
| DOI: | 10.1039/c2ta00933a |
| Popis: | In this work we have prepared a series of visible-light active Ni–Zn/Cr–CO32− LDHs with (Ni + Zn)/Cr ratio 2.0, while varying the Ni/Zn atomic ratio to 0 : 100, 25 : 75, 50 : 50, 75 : 25 and 100 : 0, and tested them for visible light photocatalytic hydrogen evolution. The photophysical and photocatalytic properties of the samples were evaluated thoroughly by PXRD, TEM and FESEM, UV-vis DRS, FTIR, PL and BET-Surface area. The PXRD measurement demonstrates a characteristic of hydrotalcite with long range order structure. The shifting of the d110 plane towards a lower angle clearly indicates that there is Ni2+ substitution in the brucite layer of Zn/Cr–CO32− LDH. Different diffuse reflectance spectra revealed that the absorption in the visible region is attributed to the metal-to-metal charge-transfer (MMCT) excitation of ZnII/NiII–O–CrIII to ZnI/NiI–O–CrIV. This oxo-bridged hetero-bimetallic assembly acts as a photo-induced centre for hydrogen evolution. The photocatalytic studies suggested that the Ni–Zn/Cr–CO32− LDH with Ni : Zn ratio of 75 : 25 exhibits the best photocatalytic activity under visible light radiation compared with the others. The detailed mechanism for the photocatalytic decomposition of water to hydrogen has also been discussed. |
| Databáze: | OpenAIRE |
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