Photocatalytic Water Oxidation by Molecular Assemblies Based on Cobalt Catalysts

Abstract

Chromophore-catalyst molecular assemblies towards visible light-driven water oxidation were synthesized by covalent integration of a light-harvesting complex [Ru(bpy)3](2+) (bpy=2,2'-bipyridine) and a Co4O4 cubane water oxidation catalyst. The two components were assembled either in linear or macrocyclic configurations. In the presence of the sacrificial reagent, the Ru-Co metallocycle exhibits remarkable photocatalytic activity for oxygen evolution, which is one order of magnitude higher than that of a multicomponent system and exceeds that of a linear assembly by a factor of five, offering access to highly active photocatalyst through molecular design.

Visible light-driven water oxidation with a ruthenium sensitizer and a cobalt-based catalyst connected with a polymeric platform

“…Although the [Ru-P4VP-CoFe] assembly showed enhanced activity and stability compared with its cobalt-based dyad (TON of 5) reported by Sun et al 38 The stability of molecular dyads have generally been investigated with relatively short-term experiments, which are in the order of minutes. This study, however, represents a dyad that maintains its activity during a 6 h photocatalytic experiment.…”

Recent Advances in First‐Row Transition Metal Clusters for Photocatalytic Water Splitting

“…From the view of the coordination chemistry, the cubane unit is the most widespread molecular structure type, and many of the 3d-metal clusters show the cubane unit. Therefore, a large series of metal clusters, such as Co/Cu/Ni/Ti-based cluster photocatalysts, [18,[28][29][30][31][32][33][34][35] were studied as photocatalytic water splitting catalysts.…”

Photoelectrochemical Water Oxidation Efficiency of a Core/Shell Array Photoanode Enhanced by a Dual Suppression Strategy

“…[4] Narrow band-gap materials, such as hematite (a-Fe 2 O 3 ), BiVO 4 ,a nd Ta ON, can improvel ight absorption, especially in the visible region. [6] An effective way to lower the barrieri st oa ttach am etal oxide or molecular electrocatalyst (EC) onto the surface of photoanodes.F or instance, Co 4 O 4 cubane, [7] IrO 2 , [8] Mn 2 O 3 , [9] Co(OH) 2 , [10] FeOOH, [11] Ni(OH) 2 ,o rN iOOH, [12] andc obalt-phosphate (Co-Pi), have been deposited onto semiconductors to lower the threshold overpotential, and thus, achieved high water oxidation reactivity. [6] An effective way to lower the barrieri st oa ttach am etal oxide or molecular electrocatalyst (EC) onto the surface of photoanodes.F or instance, Co 4 O 4 cubane, [7] IrO 2 , [8] Mn 2 O 3 , [9] Co(OH) 2 , [10] FeOOH, [11] Ni(OH) 2 ,o rN iOOH, [12] andc obalt-phosphate (Co-Pi), have been deposited onto semiconductors to lower the threshold overpotential, and thus, achieved high water oxidation reactivity.…”

“…[5] However,t he photocurrento nset potential of these semiconductors is much more positive than that of TiO 2 because of slower water oxidation kinetics that originate from severe photogenerated carrierrecombination. [6] An effective way to lower the barrieri st oa ttach am etal oxide or molecular electrocatalyst (EC) onto the surface of photoanodes.F or instance, Co 4 O 4 cubane, [7] IrO 2 , [8] Mn 2 O 3 , [9] Co(OH) 2 , [10] FeOOH, [11] Ni(OH) 2 ,o rN iOOH, [12] andc obalt-phosphate (Co-Pi), have been deposited onto semiconductors to lower the threshold overpotential, and thus, achieved high water oxidation reactivity. [13,14] Another way to modify photoanodesisthe introduction of an electron-hole-separating overlayer,which can also result in surface-state passivation.…”