| Autor: |
Katsuki, Tomohiro, Zahran, Zaki N., Hoshino, Norihisa, Tsubonouchi, Yuta, Chandra, Debraj, Yagi, Masayuki |
| Zdroj: |
Journal of Materials Chemistry A; 11/7/2024, Vol. 12 Issue 41, p28459-28474, 16p |
| Abstrakt: |
In this work, a nitrogen-doped CuWO4 (N-CuWO4) photoanode for photoelectrochemical (PEC) water oxidation was synthesized by a mixed metal-imidazole casting (MiMIC) method with 1-butylimidazole (BIm). The N-CuWO4 electrode achieved PEC water oxidation at a wavelength of 540 nm that is longer than that of the film (neat-CuWO4) prepared without BIm by 40 nm due to the N-doping, which was conscientiously characterized by spectroscopic and theoretical investigations. The N-CuWO4 surface was compactly covered with worm-like particles of 100–500 nm diameter, which is responsible for the rigid adherence of the N-CuWO4 film onto the substrate. The N-CuWO4 film showed anisotropic crystallization of triclinic CuWO4 with predominant growth of the (010) and (100) planes, in contrast to the isotropic crystallization observed for the neat-CuWO4 film. The N-CuWO4 electrode demonstrated superior performance for PEC water oxidation with an incident photon-to-electron conversion efficiency (IPCE) of 5.6% contributed by a charge separation efficiency (ηsep) of 12.3% and a catalytic efficiency (ηcat) of 51.9% (at 420 nm and 1.23 V), a faradaic efficiency (FEO2) of 97% for O2 evolution, and considerable stability for 40 h, which are advantageously comparable to those of the state-of-the-art CuWO4-based photoanodes. The water oxidation rate constant (kO2 = 1.6 × 102 s−1) at the surface for the N-CuWO4 electrode was higher than that (6.8 s−1) for the neat-CuWO4 electrode by 2 orders of magnitude, which is responsible for the high IPCE and ηcat of the N-CuWO4 electrode. The higher kO2 value for the N-CuWO4 electrode is ascribed to the higher active site on the (100) facet for water oxidation at the surface. [ABSTRACT FROM AUTHOR] |
| Databáze: |
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| Externí odkaz: |
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