Passivation of Si-photocathodes for solar water splitting
Photoelectrochemical water splitting is regarded as the feasible route for the production of green hydrogen. Silicon is one of the most convenient photocathodes for hydrogen evolution reaction, however, it rapidly degrades in electrochemical environments. Therefore, it is necessary to modify the Si surface with a layer that can protect it from (photo)corrosion while facilitating efficient charge transfer.
In this study, pulsed laser deposition was used to create a protective layer of SrTiO3 (STO) on Si. To achieve this, a template layer composed of reduced graphene oxide (rGO) between the STO film and the Si substrate was deposited, which enabled the epitaxial growth of a high-quality STO layer. This was confirmed by a thorough examination of the crystal and microstructural properties at the STO/rGO/Si interface. Our systematic PEC measurements and durability assessments revealed a significant enhancement in the PEC performance of as-prepared Si-photocathodes.
This study demonstrates a practical methodology to improve (photo)corrosion resistance and overall performance of Si-photocathodes used in solar water splitting. Dr. Milutin Smiljanić and Prof. Nejc Hodnik from the Laboratory of Electrocatalysis, Department of Materials Chemistry (D10), contributed to this interdisciplinary study, which was conducted in collaboration between the Jožef Stefan Institute, National Institute of Chemistry, and the Institute of Physics of the Czech Academy of Sciences.
Link to article: https://pubs.acs.org/doi/10.1021/acsami.3c07747
Contact for more information: milutin.smiljanic(at)ki.si