TY - JOUR
T1 - Protection of Si photocathode using TiO2 deposited by high power impulse magnetron sputtering for H2 evolution in alkaline media
AU - Bae, Dowon
AU - Shayestehaminzadeh, Seyedmohammad
AU - Thorsteinsson, Einar B.
AU - Pedersen, Thomas
AU - Hansen, Ole
AU - Seger, Brian
AU - Vesborg, Peter C.K.
AU - Ólafsson, Sveinn
AU - Chorkendorff, Ib
N1 - Publisher Copyright:
© 2015 Elsevier B.V.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Si is an excellent absorber material for use in photoelectrochemical (PEC) hydrogen production. Only a few studies have been done using Si in alkaline electrolyte for hydrogen evolution due to its poor chemical stability in high pH electrolyte, indicating that a chemically stable protection layer is essential. Here we investigate thin TiO2 films deposited by high power impulse magnetron sputtering (HiPIMS) as a protection layer for a p-type silicon photocathode for photoelectrochemical H2 evolution in a high pH electrolyte. The X-ray reflectometry analysis reveals that the HiPIMS process provides improved film density for TiO2 films (4.15 g/cm3), and consequently results in a significantly less corroded Si surface. The Si photocathode protected by the HiPIMS grown TiO2 film along with Pt as co-catalyst produced a photocurrent onset potential of ~0.5 V vs. RHE in 1 M KOH and showed a 4% decay over 24 h in KOH. In contrast, the sample with the TiO2 deposited using conventional DC sputtering technique of similar thickness shows 20% loss in photocurrent for the same time interval. Considering the fact that the experiments were carried out not in the cleanroom, much less corrosion loss can be obtained if done in dust-free condition. Hence, these results suggest the HiPIMS technique as an improved approach for the protection of photoelectrodes, which are unstable in alkaline solution.
AB - Si is an excellent absorber material for use in photoelectrochemical (PEC) hydrogen production. Only a few studies have been done using Si in alkaline electrolyte for hydrogen evolution due to its poor chemical stability in high pH electrolyte, indicating that a chemically stable protection layer is essential. Here we investigate thin TiO2 films deposited by high power impulse magnetron sputtering (HiPIMS) as a protection layer for a p-type silicon photocathode for photoelectrochemical H2 evolution in a high pH electrolyte. The X-ray reflectometry analysis reveals that the HiPIMS process provides improved film density for TiO2 films (4.15 g/cm3), and consequently results in a significantly less corroded Si surface. The Si photocathode protected by the HiPIMS grown TiO2 film along with Pt as co-catalyst produced a photocurrent onset potential of ~0.5 V vs. RHE in 1 M KOH and showed a 4% decay over 24 h in KOH. In contrast, the sample with the TiO2 deposited using conventional DC sputtering technique of similar thickness shows 20% loss in photocurrent for the same time interval. Considering the fact that the experiments were carried out not in the cleanroom, much less corrosion loss can be obtained if done in dust-free condition. Hence, these results suggest the HiPIMS technique as an improved approach for the protection of photoelectrodes, which are unstable in alkaline solution.
KW - High power impulse magnetron sputtering
KW - Hydrogen evolution
KW - Photocatalysis
KW - Titanium dioxide
UR - http://www.scopus.com/inward/record.url?scp=84946595032&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2015.10.020
DO - 10.1016/j.solmat.2015.10.020
M3 - Article
AN - SCOPUS:84946595032
SN - 0927-0248
VL - 144
SP - 758
EP - 765
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
ER -