TY - JOUR
T1 - Hematite-Based Solar Water Splitting in Acidic Solutions
T2 - Functionalization by Mono- and Multilayers of Iridium Oxygen-Evolution Catalysts
AU - Li, Wei
AU - Sheehan, Stafford W.
AU - He, Da
AU - He, Yumin
AU - Yao, Xiahui
AU - Grimm, Ronald L.
AU - Brudvig, Gary W.
AU - Wang, Dunwei
PY - 2015/9/1
Y1 - 2015/9/1
N2 - Solar water splitting in acidic solutions has important technological implications, but has not been demonstrated to date in a dual absorber photoelectrochemical cell. The lack of functionally stable water-oxidation catalysts (WOCs) in acids is a key reason for this slow development. The only WOCs that are stable at low pH are Ir-based systems, which are typically too expensive to be implemented broadly. It is now shown that this deficiency may be corrected by applying an ultra-thin monolayer of a molecular Ir WOC to hematite for solar water splitting in acidic solutions. The turn-on voltage is observed to shift cathodically by 250 mV upon the application of a monolayer of the molecular Ir WOC. When the molecular WOC is replaced by a heterogeneous multilayer derivative, stable solar water splitting for over 5 h is achieved with near-unity Faradaic efficiency.
AB - Solar water splitting in acidic solutions has important technological implications, but has not been demonstrated to date in a dual absorber photoelectrochemical cell. The lack of functionally stable water-oxidation catalysts (WOCs) in acids is a key reason for this slow development. The only WOCs that are stable at low pH are Ir-based systems, which are typically too expensive to be implemented broadly. It is now shown that this deficiency may be corrected by applying an ultra-thin monolayer of a molecular Ir WOC to hematite for solar water splitting in acidic solutions. The turn-on voltage is observed to shift cathodically by 250 mV upon the application of a monolayer of the molecular Ir WOC. When the molecular WOC is replaced by a heterogeneous multilayer derivative, stable solar water splitting for over 5 h is achieved with near-unity Faradaic efficiency.
KW - hematite
KW - homogeneous catalysis
KW - iridium
KW - photoelectrochemistry
KW - solar water splitting
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U2 - 10.1002/anie.201504427
DO - 10.1002/anie.201504427
M3 - Article
AN - SCOPUS:84942134166
VL - 54
SP - 11428
EP - 11432
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
SN - 1433-7851
IS - 39
ER -