Unbiased biocatalytic solar-to-chemical conversion by FeOOH/BiVO4/perovskite tandem structure

Abstract

Redox enzymes catalyze fascinating chemical reactions with excellent regio- and stereo-specificity. Nicotinamide adenine dinucleotide cofactor is essential in numerous redox biocatalytic reactions and needs to be regenerated because it is consumed as an equivalent during the enzymatic turnover. Here we report on unbiased photoelectrochemical tandem assembly of a photoanode (FeOOH/BiVO4) and a perovskite photovoltaic to provide sufficient potential for cofactor-dependent biocatalytic reactions. We obtain a high faradaic efficiency of 96.2% and an initial conversion rate of 2.4 mM h−1 without an external applied bias for the photoelectrochemical enzymatic conversion of α-ketoglutarate to l-glutamate via l-glutamate dehydrogenase. In addition, we achieve a total turnover number and a turnover frequency of the enzyme of 108,800 and 6200 h−1, respectively, demonstrating that the tandem configuration facilitates redox biocatalysis using light as the only energy source.

CO2‐Reductive, Copper Oxide‐Based Photobiocathode for Z‐Scheme Semi‐Artificial Leaf Structure

“…We selected a FeOOH|BiVO 4 photoanode as the counterpart of the photobiocathode because of its excellent water‐oxidizing photoelectrocatalysis, strong absorption of visible light, and PEC stability in aqueous media . We characterized BiVO 4 and FeOOH|BiVO 4 by using multiple tools (Figures S29–S32) and the analytical results were consistent with prior reports . Unbiased photoelectrocatalysis using two photoabsorber materials requires the onset potential of an oxidation reaction to be more negative than that of a reduction reaction under illumination.…”

In situ observation of pH change during water splitting in neutral pH conditions: impact of natural convection driven by buoyancy effects

“…78,79 The (photo)electrochemical reduction of nicotinamide adenine dinucleotide (NAD + ) results in a versatile reducing agent that can be used for a wide range of biocatalytic redox reactions to produce valuable chemicals. 80,81 All of these reactions involve proton coupled electron transfer reactions without forming product gas bubbles, and in all these cases it is desirable to minimize pH shifts during reactions. In order to shed light on the potential impact of buoyancy-driven convection for such reactions at current densities beyond 2 mA/cm 2 , additional calculations were performed.…”

Continuous 3D Titanium Nitride Nanoshell Structure for Solar‐Driven Unbiased Biocatalytic CO2 Reduction

“…We confirmed that ClFDH was not degraded to W‐ or Fe 4 S 4 ‐based heterogeneous catalysts on the surface of the 3D TiN nanoshell electrode even after the long‐term operation under high photopotential (Figures S20 and S21, Supporting Information). Nonetheless, the operating current and formate generation rate of biocatalytic tandem PEC system gradually declined with prolonged reaction time, which is ascribed to the instability of triple‐cation perovskite PV cells under ambient humid conditions . Further studies about the enhancement of perovskite durability are needed for robust and sustainable biocatalytic PEC cells.…”