Visible Light-Driven H₂ Production by Hydrogenases Attached to Dye-Sensitized TiO₂ Nanoparticles

Abstract

A study of hybrid, enzyme-modified nanoparticles able to produce H(2) using visible light as the energy source has been carried out to establish per-site performance standards for H(2) production catalysts able to operate under ambient conditions. The [NiFeSe]-hydrogenase from Desulfomicrobium baculatum (Db [NiFeSe]-H) is identified as a particularly proficient catalyst. The optimized system consisting of Db [NiFeSe]-H attached to Ru dye-sensitized TiO(2), with triethanolamine as a sacrificial electron donor, produces H(2) at a turnover frequency of approximately 50 (mol H(2)) s(-1) (mol total hydrogenase)(-1) at pH 7 and 25 degrees C, even under the typical solar irradiation of a northern European sky. The system shows high electrocatalytic stability not only under anaerobic conditions but also after prolonged exposure to air, thus making it sufficiently robust for benchtop applications.

Hydrogen production at high Faradaic efficiency by a bio-electrode based on TiO2 adsorption of a new [FeFe]-hydrogenase from Clostridium perfringens

“…5 To this end both [NiFe]-and [FeFe]-hydrogenases (H2ases) have been used on a wide variety of solid electrodes, such as pyrolytic graphite edge (PGE), glassy carbon and carbon felt electrodes, gold electrodes, TiO2 electrodes but also carbon nanotubes and nanowires, CdTe nanocrystals and CdS nanorods. Electrochemical, photoluminescence and Raman spectroscopy studies demonstrate that the hydrogenases remain catalytically active and therefore can be exploited as efficient catalysts [5][6][7][8][9][10]. Several electrochemical setups have been proposed exploiting the catalytic properties of both 10 [NiFe]-and [FeFe]-hydrogenases from various bacterial and some algal species [6,[11][12].…”

“…In fact, the ability of RuP-TiO2 nanoparticles to absorb both UV and visible light has been exploited for light-driven H2 production by 20 D. baculatum [NiFeSe]-H2ase absorbed on it [7]. Not only titanium oxide, but also other materials like CdTe and CdS show intrinsic photochemical properties so the photochemical H2 production by CdS nanorod and CdTe nanocrystal [FeFe]-H2ase complexes has been well investigated [8,13].…”

Photobiocatalysis: The Power of Combining Photocatalysis and Enzymes

“…Considering the well documented efficiency of hydrogenases in electrochemical H 2 generation, it is not surprising that these enzymes can also act as replacement of Pt NPs in [85] Scheme 20. Operation and advantages of a photobiocatalytic system based on TiO 2 semiconductor, ruthenium polypyridyl dye as light harvester and a {NiFeS} hydrogenase as cocatalyst in the absence of cofactors and electron mediators (TEOA: triethanolamine).…”

“…Operation and advantages of a photobiocatalytic system based on TiO 2 semiconductor, ruthenium polypyridyl dye as light harvester and a {NiFeS} hydrogenase as cocatalyst in the absence of cofactors and electron mediators (TEOA: triethanolamine). (Figure taken with permission from ref [85] ).…”

“…The excellent anchoring of [NiFeS]-hydrogenase to TiO 2 seems to derive from the presence in the enzyme of lateral carboxylate groups. Carboxylic acid groups are known to attach strongly to the TiO 2 surface [85] .…”