Bioinspired Metalation of the Metal‐Organic Framework MIL‐125‐NH₂ for Photocatalytic NADH Regeneration and Gas‐Liquid‐Solid Three‐Phase Enzymatic CO₂ Reduction

Abstract

Coenzyme NADH regeneration is crucial for sustained photoenzymatic catalysis of CO 2 reduction. However, light-driven NADH regeneration still suffers from the low regeneration efficiency and requires the use of a homogeneous Rh complex. Herein, a Rh complex-based electron transfer unit was chemically attached onto the linker of the MIL-125-NH 2 . The coupling between the light-harvesting iminopyridine unit and electron-transferring Rh-complex facilitated the photo-induced electron transfer for the NADH regeneration with the yield of 66.4 % in 60 mins for 5 cycles. The formate dehydrogenase was further deposited onto the hydrophobic layer of the membrane by a reverse filtering technique, which forms the gas-liquid-solid reaction interface around the enzyme site. It gave an enhanced formic acid yield of 9.5 mM in 24 hours coupled with the in situ regenerated NADH. The work could shed light on the construction of integrated inorganic-enzyme hybrid systems for artificial photosynthesis.

Recent advances in porous materials for photocatalytic NADH regeneration

“…NADH is capable of coupling oxidoreductases to catalyze a very large number of important reactions, such as hydroxylation and CO 2 reduction reactions. 45,46 We take eqn (6) as an example, where α-ketoglutarate is reduced to l -glutamate under the catalysis of glutamate dehydrogenase. Among them, NADH loses electrons and protons as a reducing agent, and α-ketoglutarate gains these electrons and protons, and is converted to l -glutamate.…”

“…This coupling facilitated photogenerated electron transfer, which resulted in the NADH regeneration efficiency reaching 66.4% at 60 min. 45 In the work of another group, the Rh complex was also anchored to the organic linker, but they further enhanced the photocatalytic NADH regeneration efficiency by boosting the electronic availability and activity. The URh prepared by Wu et al (Fig.…”

Fine-Tuning the Electrocatalytic Regeneration of NADH Cofactor Using [Rh(Cp*)(bpy)Cl]+-Functionalized Metal–Organic Framework Films

“…Thus, a rational design of the porous structure and a precise control of catalyst loading is highly desirable for the development of efficient functional bioelectrodes. Different types of metal−organic framework (MOF) materials with porous crystalline structures were explored for a variety of potential applications, 13,14 including in the field of electrochemistry. 15−19 NU-1000 is a zirconium-based metal−organic framework with a modular porous structure, which can be tailored by different functional groups.…”

Room Temperature design of Ce(IV)-MOFs: from photocatalytic HER and OER to overall water splitting under simulated sunlight irradiation

“…For instance, 2-amino-1,4-benzenedicarboxylic acid, also denoted here 'BDC-NH2', is a typical commercially available electron-donating linker associated with a shift of its optical absorption toward the visible range and an enhancement of both the ligand-metal charge transfer (LMCT) and the separation of electrons and holes upon photoexcitation compared to BDC. This topical ligand has so far been combined with almost any type of metals leading to series of amino-functionalized benchmark MOFs such as Zn-MOF-5-NH2, 21 Cr-MIL-101-NH2, 22 Al-MIL-53-NH2, 23 Fe-MIL-88-NH2, 24 Ti-MIL-125-NH2, 25 Zr-UiO-66-NH2 26 , among many others. Concerning Ce-UiO-66-NH2, very recent efforts to prepare this phase have been focused on either the use of a solvent-assisted linker exchange (SALE, up to 85% linker exchange) in DMF, where the BDC-NH2 could replace the original BDC ligand from the framework, 32 or on the fabrication of Ce-UiO-66-NH2 through the use of pre-formed Ce6 oxoclusters in DMF.…”