Harvesting resonantly-trapped light for small molecule oxidation reactions at the Au/α-Fe2O3 interface
| Autor: | David R. Baker, Kyle N. Grew, Joshua P. McClure, Eric Gobrogge, Naresh C. Das, Deryn Chu |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Band gap Annealing (metallurgy) business.industry 02 engineering and technology Overpotential 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences Electron beam physical vapor deposition 0104 chemical sciences Metal Semiconductor visual_art Electrode visual_art.visual_art_medium General Materials Science Thin film 0210 nano-technology business |
| Zdroj: | Nanoscale. 10:7833-7850 |
| ISSN: | 2040-3372 2040-3364 |
| DOI: | 10.1039/c8nr01330f |
| Popis: | Plasmonic metal nanoparticles (NPs) extend the overall light absorption of semiconductor materials. However, it is not well understood how coupling metal NPs to semiconductors alters the photo-electrochemical activity of small molecule oxidation (SMO) reactions. Different photo-anode electrodes comprised of Au NPs and α-Fe2O3 are designed to elucidate how the coupling plays not only a role in the water oxidation reaction (WO) but also performs for different SMO reactions. In this regard, Au NPs are inserted at specific regions within and/or on α-Fe2O3 layers created with a sequential electron beam evaporation method and multiple annealing treatments. The SMO and WO reactions are probed with broad-spectrum irradiation experiments with an emphasis on light-driven enhancements above and below the α-Fe2O3 band gap. Thin films of α-Fe2O3 supported on a gold back reflective layer resonantly-traps incident light leading to enhanced SMO/WO conversion efficiencies at high overpotential (η) for above band-gap excitations with no SMO activity observed at low η. In contrast, a substantial increase in the light-driven SMO activity is observed at low η, as well as for below band-gap excitations when sufficiently thin α-Fe2O3 films are decorated with Au NPs at the solution-electrode interface. The enhanced photo-catalytic activity is correlated with increased surface oxygen content (hydroxyl groups) at the Au/α-Fe2O3 interface, as well as simulated volume-integrated near-field enhancements over select regions of the Au/α-Fe2O3 interface providing an important platform for future SMO/WO photo-electrocatalyst development. |
| Databáze: | OpenAIRE |
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