Solar‐Assisted eBiorefinery: Photoelectrochemical Pairing of Oxyfunctionalization and Hydrogenation Reactions

Abstract

Inspired by natural photosynthesis, biocatalytic photoelectrochemical (PEC) platforms are gaining prominence for the conversion of solar energy into useful chemicals by combining redox biocatalysis and photoelectrocatalysis. Herein, we report a dual biocatalytic PEC platform consisting of a molybdenum (Mo)‐doped BiVO4 (Mo:BiVO4) photoanode and an inverse opal ITO (IO‐ITO) cathode that gives rise to the coupling of peroxygenase and ene‐reductase‐mediated catalysis, respectively. In the PEC cell, the photoexcited electrons generated from the Mo:BiVO4 are transferred to the IO‐ITO and regenerate reduced flavin mononucleotides to drive ene‐reductase‐catalyzed trans‐hydrogenation of ketoisophrone to (R)‐levodione. Meanwhile, the photoactivated Mo:BiVO4 evolves H2O2 in situ via a two‐electron water‐oxidation process with the aid of an applied bias, which simultaneously supplies peroxygenases to drive selective hydroxylation of ethylbenzene into enantiopure (R)‐1‐phenyl‐1‐hydroxyethane. Thus, the deliberate integration of PEC systems with redox biocatalytic reactions can simultaneously produce valuable chemicals on both electrodes using solar‐powered electrons and water.

Paired photoelectrochemical conversion of CO2/H2O and glycerol at high rate

“…Using a molecular redox mediator a near-quantitative yield and 100% Faradaic efficiency (FE) was achieved. In another, bio-PEC approach 33 , a Mo:BiVO 4 photoanode was employed to generate H 2 O 2 in situ, which simultaneously supplied peroxygenases to drive a selective hydroxylation reaction.…”

Ene‐Reductase: A Multifaceted Biocatalyst in Organic Synthesis

“…Advantageously, the reaction was more facile and productive under light illumination (>420 nm) and the reaction impeded the enantioselectivity in the absence of Ts OYE. A further report by the Park group unveiled a dual biocatalytic photoelectrochemical method using hexavalent molybdenum doped BiVO 4 as photoanode and an inverse opal ITO (IO‐ITO) as a photocathode [98] . Upon irradiation of solar light, a photoelectron was generated in the photoanode, which was transferred to the photocathode via an external circuit and regenerated the flavin cofactor to carry out the trans ‐hydrogenation by ene‐reductase enzymes.…”

Optical and Photocatalytic Properties of Three-Dimensionally Ordered Macroporous Ta2O5 and Ta3N5 Inverse Opals

“…These properties make it a particularly attractive material for creating optical and optoelectronic devices, including sensors, filters, lasers, and photographic lenses. − Further, the combination of a high dielectric constant (ε = 29, increasing to 90–110 in thin films) and wide electronic band gap ( E g = 4.0) lead to further application in capacitors and other electronic devices. Surprisingly, given the excellent optical properties of Ta 2 O 5 , very little work has been reported to date relating to the fabrication of Ta 2 O 5 inverse opals operating in the visible regime. − The 3DOM structure of inverse opals, together with their inherent photonic crystal properties, is expected to create new opportunities for Ta 2 O 5 in optical sensor development, − photocatalysis, − and catalysis, ,,− motivating a detailed investigation. Furthermore, Ta 2 O 5 is an important starting material in the preparation of TaON and Ta 3 N 5 photocatalysts for visible-light-driven hydrogen production.…”