Boudoire, Florent. Self-assembled photonic mesostructures for water splitting photoanodes. 2015, PhD Thesis, University of Basel, Faculty of Science.
Available under License CC BY-NC-ND (Attribution-NonCommercial-NoDerivatives).
Official URL: http://edoc.unibas.ch/diss/DissB_11291
Materials of interest for application as photoanode for photoelectrochemical water splitting are metal oxides because of their resistance to corrosion. In this thesis I focused on two of these oxides, namely hematite (alpha-Fe2O3) and monoclinic tungsten oxide (mWO3) since these materials have a relatively narrow band gap allowing absorption of a significant part of sun's irradiance. In a photoanode they were implemented as thin films on a conductive substrate. I proposed to investigate inexpensive and upscalable structuration processes for the formation of such photoanodes thin films with a controlled microstructure and studied the impact of such structures on the film photoelectrochemical performance.
Self-assembly strategies are bottom-up approaches which allow to grow structures with original morphologies at a low cost compared to top-down techniques such as lithography. I was particularly interested in strategies that would grant a fine control of the feature sizes. Two different processing techniques were implemented, a polymer templated sol-gel route and electrohydrodynamic lithography. Both techniques allowed to obtain metal oxides structures at the meso- to nanoscale. The polymer templated sol-gel route was the most successful strategy. It allowed to produce microspheroids with a tungsten oxide core and a hematite nanometric overlayer with control on the structure dimensions.
In addition to an in depth understanding of the different bottom-up approaches investigated, I proposed a complete description of the relationship between form and function in the film composed of tungsten oxide / hematite microspheroids. These films have significant photonic features linked to their original morphology and I discussed how their photoactivity is influenced by light trapping in these films.
|Advisors:||Constable, Edwin C.|
|Committee Members:||Braun, Artur and Sivula, Kevin|
|Faculties and Departments:||05 Faculty of Science > Departement Chemie > Chemie > Anorganische Chemie (Constable)|
|Bibsysno:||Link to catalogue|
|Number of Pages:||117 p.|
|Last Modified:||30 Jun 2016 10:57|
|Deposited On:||14 Jul 2015 13:14|
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