Metal Hydride-Embedded Titania Coating to Coordinate Electron Transfer and Enzyme Protection in Photo-enzymatic Catalysis

Abstract

Albeit that photo-enzymatic catalysis has sparked more and more attention, its efficiency is restricted by lower electron transfer and poor compatibility between the natural enzyme and synthetic photocatalyst. Herein, a metal hydride-embedded titania (MH/TiO2) coating is engineered on graphitic carbon nitride (GCN) to coordinate electron transfer and enzyme protection for photo-enzymatic alcohol production. The MH/TiO2 coating plays two vital roles: (1) protecting alcohol dehydrogenase (ADH) from deactivation by the GCN core and MH in the coating and (2) permitting electron transfer from GCN to nicotinamide adenine dinucleotide (NAD+) and then to formaldehyde catalyzed by ADH. The coordinated photo-enzymatic system could produce methanol at a rate of 1.78 ± 0.21 μmol min–1 mg­(ADH)−1, which is 420% higher than that of the system composed of ADH and GCN without the coating. Moreover, the coordinated system could continuously produce methanol for at least three light–dark cycles, while the system composed of GCN and ADH is completely deactivated after one light–dark cycle. Our study unveils the potential of redox-active mineral coating in coordinating synthetic and biological modules for solar chemical conversion.

Granum-Inspired Photoenzyme-Coupled Catalytic System via Stacked Polymeric Carbon Nitride

“…However, majority of the abovementioned structures of photocatalysts were not suitable for enzyme immobilization. Furthermore, in most PECCSs, enzymes existed in a free form, which led to a longer diffusion distance of intermediates and ultimately led to inefficient utilization by the enzymatic module. ,,,, Therefore, a PECCS that could realize the efficient generation of intermediates by the photocatalytic module as well as efficient utilization of intermediates by the enzymatic module is particularly desired.…”

“…Furthermore, in most PECCSs, enzymes existed in a free form, which led to a longer diffusion distance of intermediates and ultimately led to inefficient utilization by the enzymatic module. 5,29,30,35,38 Therefore, a PECCS that could realize the efficient generation of intermediates by the photocatalytic module as well as efficient utilization of intermediates by the enzymatic module is particularly desired. Herein, stacked tubular polymeric carbon nitride (st-PCN*) is designed as both a photocatalyst and a carrier for chlorperoxidase (CPO), constructing the st-PCN*@CPO PECCS to implement the cascade chlorination reaction (Figure 1).…”

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

“…As shown in Figure 2g, the high-resolution Rh 3d spectrum displayed two peaks at 309.8 and 314.5 eV, which arised from the Rh 3d 5/2 and Rh 3d 3/2 states of the Rh III complex, respectively. [25,27,28] The Cl 2p spectrum demonstrated the conjugation of Rh complex onto (MIL-125-Py-Rh) 0.05 (Figure S6). The corresponding N 1s spectrum (Figure S7a) with peaks at � 403.12 and � 399.57 eV showed a slight shift toward the lower binding energy compared to that of MIL-125-NH 2 and (MIL-125-Py) 0.05 , further revealing the existence of interac-…”

“…[16][17][18] Photocatalytic NADH regeneration usually occurs in the presence of photocatalysts as well as homogeneous metal complex (such as [Cp*Rh(bpy)H 2 O] 2 + ), which act as the electron and proton mediator. [19][20][21][22][23][24][25] Previously, most of the photoinduced electrons were transferred from the heterogeneous semiconductor particles to the homogeneous Rh complex to accomplish the first step of the photocatalytic NADH regeneration, which could pose severe electron transfer loss. Moreover, the homogeneous Rh complex is prone to poisoning enzymes, reducing the reaction efficiency.…”

Photoenzymatic Activity of Artificial–Natural Bienzyme Applied in Biodegradation of Methylene Blue and Accelerating Polymerization of Dopamine

“…In addition to immobilizing or encapsulating various enzymes for combating the easy loss of enzymatic activity, strengthening the enzymatic activity upon light irradiation is also a challenge . In general, the mechanisms for modulating the enzyme activity can be briefly performed via improving the local temperature, producing electrons and holes, and using local surface plasmon resonance (LSPR) to activate the enzyme activity. In the past decades, some efforts had been reported to control the enzyme activity by irradiation with different lights such as UV, blue, and visible light .…”