TY - JOUR
T1 - A Molecular Silane-Derivatized Ru(II) Catalyst for Photoelectrochemical Water Oxidation
AU - Wu, Lei
AU - Eberhart, Michael
AU - Nayak, Animesh
AU - Brennaman, M. Kyle
AU - Shan, Bing
AU - Meyer, Thomas J.
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/11/7
Y1 - 2018/11/7
N2 - Photoanodes in dye-sensitized photoelectrosynthesis cells integrate molecular chromophore/catalyst assemblies on mesoporous n-type metal oxide electrodes for light-driven water oxidation. One limitation for sustainable photoanodes is the stability of chromophore/catalyst assembly on electrode surfaces for long periods. Progress has been made in stabilizing chromophores based on atomic layer deposition, polymer dip coating, C-C cross-coupling by electropolymerization, and silane surface binding, but little progress has been made on catalyst stabilization. We report here the silane-derivatized catalyst, Ru(bda)(L)2 (bda = 2,2′-bipyridine-6,6′-dicarboxylate, L = 4-(6-(triethoxysilyl)hexyl)pyridine), catalyst 1, which is stabilized on metal oxide electrode surfaces over an extended pH range. A surface stabilization study shows that it maintains its reactivity on the electrode surface toward electrochemical oxidation over a wide range of conditions. Its electrochemical stability on electrode surfaces has been systematically evaluated, and its role as a catalyst for water oxidation has been explored. On surfaces of mesoporous nanostructured core/shell SnO2/TiO2, with a TiO2 stabilized inner layer of the Ru(II) polypyridyl chromophore, [Ru(4,4′-(PO3H2)2bpy)(bpy)2]2+ (RuP2+ bpy = 2,2′-bipyridine), highly efficient photoelectrochemical water oxidation catalysis occurs to produce O2 with a maximum efficiency of ∼1.25 mA/cm2. Long-term loss of catalytic activity occurs with time owing to catalyst loss from the electrode surface by axial ligand dissociation in the high oxidation states of the catalyst.
AB - Photoanodes in dye-sensitized photoelectrosynthesis cells integrate molecular chromophore/catalyst assemblies on mesoporous n-type metal oxide electrodes for light-driven water oxidation. One limitation for sustainable photoanodes is the stability of chromophore/catalyst assembly on electrode surfaces for long periods. Progress has been made in stabilizing chromophores based on atomic layer deposition, polymer dip coating, C-C cross-coupling by electropolymerization, and silane surface binding, but little progress has been made on catalyst stabilization. We report here the silane-derivatized catalyst, Ru(bda)(L)2 (bda = 2,2′-bipyridine-6,6′-dicarboxylate, L = 4-(6-(triethoxysilyl)hexyl)pyridine), catalyst 1, which is stabilized on metal oxide electrode surfaces over an extended pH range. A surface stabilization study shows that it maintains its reactivity on the electrode surface toward electrochemical oxidation over a wide range of conditions. Its electrochemical stability on electrode surfaces has been systematically evaluated, and its role as a catalyst for water oxidation has been explored. On surfaces of mesoporous nanostructured core/shell SnO2/TiO2, with a TiO2 stabilized inner layer of the Ru(II) polypyridyl chromophore, [Ru(4,4′-(PO3H2)2bpy)(bpy)2]2+ (RuP2+ bpy = 2,2′-bipyridine), highly efficient photoelectrochemical water oxidation catalysis occurs to produce O2 with a maximum efficiency of ∼1.25 mA/cm2. Long-term loss of catalytic activity occurs with time owing to catalyst loss from the electrode surface by axial ligand dissociation in the high oxidation states of the catalyst.
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U2 - 10.1021/jacs.8b10132
DO - 10.1021/jacs.8b10132
M3 - Article
C2 - 30371065
AN - SCOPUS:85056125020
SN - 0002-7863
VL - 140
SP - 15062
EP - 15069
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 44
ER -