Proton Reduction Using a Hydrogenase-Modified Nanoporous Black Silicon Photoelectrode
| Autor: | Yixin Zhao, Kai Zhu, Nicholas C. Anderson, John A. Turner, Michael W. Ratzloff, David W. Mulder, Howard M. Branz, Nathan R. Neale, Paul W. King |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Silicon
Materials science Hydrogenase Light Inorganic chemistry chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Photocathode chemistry.chemical_compound Nanopores General Materials Science Electrodes Nanoporous Black silicon 021001 nanoscience & nanotechnology 0104 chemical sciences Turnover number Light intensity chemistry Chemical engineering Electrode Protons 0210 nano-technology Hydrogen |
| Zdroj: | ACS applied materialsinterfaces. 8(23) |
| ISSN: | 1944-8252 |
| Popis: | Metalloenzymes featuring earth-abundant metal-based cores exhibit rates for catalytic processes such as hydrogen evolution comparable to those of noble metals. Realizing these superb catalytic properties in artificial systems is challenging owing to the difficulty of effectively interfacing metalloenzymes with an electrode surface in a manner that supports efficient charge-transfer. Here, we demonstrate that a nanoporous "black" silicon (b-Si) photocathode provides a unique interface for binding an adsorbed [FeFe]-hydrogenase enzyme ([FeFe]-H2ase). The resulting [FeFe]-H2ase/b-Si photoelectrode displays a 280 mV more positive onset potential for hydrogen generation than bare b-Si without hydrogenase, similar to that observed for a b-Si/Pt photoelectrode at the same light intensity. Additionally, we show that this H2ase/b-Si electrode exhibits a turnover frequency of ≥1300 s(-1) and a turnover number above 10(7) and sustains current densities of at least 1 mA/cm(2) based on the actual surface area of the electrode (not the smaller projected geometric area), orders of magnitude greater than that observed for previous enzyme-catalyzed electrodes. While the long-term stability of hydrogenase on the b-Si surface remains too low for practical applications, this work extends the proof-of-concept that biologically derived metalloenzymes can be interfaced with inorganic substrates to support technologically relevant current densities. |
| Databáze: | OpenAIRE |
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