title: Decoupling feature size and functionality in solution-processed, porous hematite electrodes for solar water splitting.
abstract: We introduce a simple solution-based strategy to decouple morphological and functional effects of annealing nanostructured, porous electrodes by encapsulation with a SiO(2) confinement scaffold before high temperature treatment. We demonstrate the effectiveness of this approach using porous hematite (α-Fe(2)O(3)) photoanodes applied for the storage of solar energy via water splitting and show that the feature size and electrode functionality due to dopant activation can be independently controlled. This allows a significant increase in water oxidation photocurrent from 1.57 mA cm(-2) (in the control case) to 2.34 mA cm(-2) under standard illumination conditions in 1 M NaOH electrolyte-the highest reported for a solution-processed hematite photoanode. This increase is attributed to the improved quantum efficiency, especially with longer wavelength photons, due to a smaller particle size, which is afforded by our encapsulation strategy.
authors.affiliation: Laboratoire de photonique et interfaces, Institut des sciences et ingénierie chimiques, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: Jeremie
authors.initials: J
authors.lastname: Brillet
authors.forename: Michael
authors.initials: M
authors.lastname: Grätzel
authors.forename: Kevin
authors.initials: K
authors.lastname: Sivula