Photochemical Production of Hydrogen from Water Using Microporous Porphyrin Coordination Lattices

Abstract

In this study, we investigated the photochemical production of hydrogen from water using bio-inspired heterogeneous microporous porphyrin coordination lattices (PCLs), [Ru2(MTCPP)BF4] (M = H2 (PCL-1), Zn (PCL-2); TCPP = Tetrakis(4-carboxyphenyl)porphyrin), under visible (380 nm <) and UV (320 nm <) light irradiations. In the presence of Na2EDTA (as a sacrificial donor) and MV2+ (methyl-vilologen; as a electron relay), PCLs exhibits photocatalytic activity for hydrogen evolution; the maximum amounts of turnover numbers (TONs) of PCL-1 and PCL-2 at 24 h irradiation were 20.8 and 29.9, respectively. In the catalytic reactions, the relation between PCLs and MV2+ was similar to the relation between a [cytochrome c3 hydrogenase] pair and lysine residues in enzymatic reactions. By using the hydrogen production rate and the MV+ (methyl-vilologen radical-cation) concentration, kinetic parameters such as affinities between MV+ and PCLs, maximum reaction rate, and total efficiency of the reaction are introduced using the Michaelis-Menten equation. These parameters indicated that PCLs are good artificial enzyme model catalysts. The stability of the PCLs after the catalytic reactions was confirmed by X-ray photoelectron spectroscopy and Fourier transform-infrared spectra. These results indicated that the frameworks of PCLs are stable for this catalytic reaction.

Photocatalytic Hydrogen Evolution over Exfoliated Rh-Doped Titanate Nanosheets

“…All photochemical reactions were performed in a closed gas circulation system with a Pyrex reaction cell. , The reaction solution (10 cm 3 ) containing TEA (0.36 mol/dm 3 , pH ∼ 10–11) and Ti 3 NS:Rh­( x ) or Rh­( x ) - Ti 3 NS colloidal suspension (1 mg) was degassed by repeated freeze pump–thaw cycles. The reaction solution was shifted into the reaction vessel with a glovebox under an Ar-saturated atmosphere.…”

Photocatalytic activity of α-PbO2-type TiO2

“…The essence of the closed circulatory system was described in the Supporting Information. Preparation and measurements were performed in the same manner as described elsewhere . For each measurement, it was used that 50 mg of the samples, 10 ml of water and 558 mg of EDTA‐2Na, which acted as the sacrificial reagent.…”

Energy-Related Small Molecule Activation Reactions: Oxygen Reduction and Hydrogen and Oxygen Evolution Reactions Catalyzed by Porphyrin- and Corrole-Based Systems

“…357 Other porphyrin diruthenium-based MOF materials were reported by Mori and co-workers as photocatalysts for H 2 evolution. 358 Because Ru and Fe are in the same group and share similar chemical properties, these porphyrin dirutheniumbased MOF complexes are discussed in this subsection. Photocatalytic studies showed relatively low activity.…”