Research output: Contribution to journal › Article › peer-review
Irreversible surface changes upon n-type doping – A photoelectrochemical study on rutile single crystals. / Haisch, Christoph; Günnemann, Carsten; Melchers, Stephanie; Fleisch, Manuel; Schneider, Jenny; Emeline, Alexei V.; Bahnemann, Detlef W.
In: Electrochimica Acta, Vol. 280, 01.08.2018, p. 278-289.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Irreversible surface changes upon n-type doping – A photoelectrochemical study on rutile single crystals
AU - Haisch, Christoph
AU - Günnemann, Carsten
AU - Melchers, Stephanie
AU - Fleisch, Manuel
AU - Schneider, Jenny
AU - Emeline, Alexei V.
AU - Bahnemann, Detlef W.
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Single crystal wafers need to provide sufficient electrical conductivity to be employed in photoelectrochemical investigations. Usually, their defect concentrations and donor densities are too low to allow electrochemical measurements. Accordingly, TiO2 rutile single crystal surfaces have to be n-type doped before their electrochemical activity can be evaluated. The doping itself, however, leads to irreversible changes in the surface morphology of the initially smooth crystalline surfaces. In this study, the effects of n-type doping and photoetching on TiO2 rutile single crystal surfaces have been investigated. The photocatalytic and photoelectrochemical activities of the rutile single crystal wafers have been quantified by methanol photooxidation. The results indicate that n-type doping has different impacts on the employed rutile (100) and (110) surfaces. Subsequent photoetching is necessary to achieve comparable donor densities for both single crystal electrodes. Moreover, the rutile (100) surface is producing different product ratios depending on the applied external bias as compared with the rutile (110) surface for methanol and water oxidation.
AB - Single crystal wafers need to provide sufficient electrical conductivity to be employed in photoelectrochemical investigations. Usually, their defect concentrations and donor densities are too low to allow electrochemical measurements. Accordingly, TiO2 rutile single crystal surfaces have to be n-type doped before their electrochemical activity can be evaluated. The doping itself, however, leads to irreversible changes in the surface morphology of the initially smooth crystalline surfaces. In this study, the effects of n-type doping and photoetching on TiO2 rutile single crystal surfaces have been investigated. The photocatalytic and photoelectrochemical activities of the rutile single crystal wafers have been quantified by methanol photooxidation. The results indicate that n-type doping has different impacts on the employed rutile (100) and (110) surfaces. Subsequent photoetching is necessary to achieve comparable donor densities for both single crystal electrodes. Moreover, the rutile (100) surface is producing different product ratios depending on the applied external bias as compared with the rutile (110) surface for methanol and water oxidation.
KW - Methanol oxidation
KW - n-type doping
KW - Photoelectrochemistry
KW - Photoetching
KW - Rutile
KW - Single crystal
KW - Titanium dioxide photocatalysis
KW - PHOTOCATALYTIC PROPERTIES
KW - METHANOL
KW - SEMICONDUCTOR
KW - WATER-OXIDATION
KW - DEPENDENCE
KW - TIO2 SURFACES
KW - OH RADICAL FORMATION
KW - PHOTOOXIDATION REACTION
KW - MORPHOLOGY
KW - ELECTRONIC-STRUCTURE
UR - http://www.scopus.com/inward/record.url?scp=85047642196&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2018.05.105
DO - 10.1016/j.electacta.2018.05.105
M3 - Article
AN - SCOPUS:85047642196
VL - 280
SP - 278
EP - 289
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
ER -
ID: 28700255