Cu2O nanowire arrays electrodeposited in etched ion-track membranes as photocathodes for solar water splitting
Florent Yang a, Jan Kugelstadt a, Mercedes Alicia Carrillo-Solano a, Wouter Maijenburg a, Christina Trautmann a, Maria Eugenia Toimil-Molares a
a GSI Helmholtz Centre for Heavy Ion Research, Planckstrasse 1, Darmstadt, 64291, Germany
Materials for Sustainable Development Conference (MATSUS)
Proceedings of nanoGe September Meeting 2017 (NFM17)
SF1: Material and Device Innovations for the Practical Implementation of Solar Fuels (SolarFuel17)
Barcelona, Spain, 2017 September 4th - 9th
Organizers: Wilson Smith and Ki Tae Nam
Poster, Florent Yang, 107
Publication date: 20th June 2016

Research on the synthesis and characterization of semiconductor nanowires is continuously increasing especially for applications in the field of energy conversion, such as for instance solar cells, photocatalysis, and photoelectrochemical water splitting for hydrogen production [1]. One attractive approach to improve the efficiency of solar to hydrogen conversion is the use of nanowire architectures since, in comparison to films, they offer larger surface areas and permit to dramatically reduce the ratio of the minority carrier diffusion length over the light absorption depth [2]. Among the various materials studied as photocathodes for hydrogen production via water splitting, Cu2O is a promising candidate. A solar-to-hydrogen conversion efficiency of ~18% has been predicted for this p-type semiconductor with a band gap of 2 eV [3]. Moreover, Cu2O has favorable band energy positions for water splitting and is also earth-abundant, scalable, non-toxic, and compatible with low-cost fabrication processes. Its chemical stability in aqueous solution can be improved by adding protection layers.

Among the various methods available to synthesize Cu2O nanowires, we apply ion-track nanotechnology [4]. The fabrication and characterization of parallel and highly textured Cu2O nanowire arrays obtained by electrodeposition in etched ion-track membranes will be presented. Nanowire diameter, length, number density, and crystallinity are adjusted in a controlled and systematic manner during the synthesis. After removal of the polymer membrane in an organic solvent, the freestanding nanowire arrays are coated by an additional electrodeposited Cu2O layer to avoid direct contact between the electrolyte and the metallic support layer. Finally, a conformal TiO2 film is applied by atomic layer deposition. Photoelectrochemical measurements on these nanowire-based electrodes will be presented, and the influence of their geometrical characteristics on their photoelectrochemical performance will be discussed.

 

References

[1] A. I. Hochbaum, P. Yang, Chem. Rev. 2010, 110, 527-546.

[2] R. van de Krol, M. Grätzel, Photoelectrochemical Hydrogen Production, Springer, 2012.

[3] A. Paracchino, V. Laporte, K. Sivula, M. Grätzel, E. Thimsen, Nat. Mater. 2011, 10, 456-461.

[4] M. E. Toimil-Molares, Beilstein J. Nanotechnol. 2012, 3, 860–883.

© FUNDACIO DE LA COMUNITAT VALENCIANA SCITO
We use our own and third party cookies for analysing and measuring usage of our website to improve our services. If you continue browsing, we consider accepting its use. You can check our Cookies Policy in which you will also find how to configure your web browser for the use of cookies. More info