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

Abstract

Photoenzyme-coupled catalysis has become a powerful platform for chemical manufacturing, in which energybearing intermediates are often shuttled between a photocatalytic module and an enzymatic module. A photoenzyme-coupled catalytic system (PECCS) to realize the generation of intermediates by the photocatalytic module and utilization of intermediates by the enzymatic module is highly desired. Inspired by the structure and function of a granum, 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. st-PCN* ensures oriented electron transfer, achieving the H 2 O 2 evolution rate of 150 μmol h −1 g −1 (st-PCN*), over 55-and 2-fold that of bulky PCN (b-PCN) and bulky PCN* (b-PCN*). Meanwhile, st-PCN* shortens the diffusion distance of H 2 O 2 from st-PCN* to CPO. Under simulated sunlight irradiation, our st-PCN*@CPO PECCS realizes in situ, continuous, and controllable supply of H 2 O 2 to CPO, followed by converting monochlorodimedone (MCD) into dichlordimedone (DCD) with a final conversion ratio of ∼39.5%. The initial reaction rate could reach 0.29 mM h −1 , over 20-fold that of its counterpart PECCS with a nonstacked structured photocatalyst. Our study unveils the potential of exploring the stacked structure to coordinate cascade catalytic processes.

Artificial photosynthesis systems for solar energy conversion and storage: platforms and their realities

“…Jiang and coworkers developed stacked tubular polymeric carbon nitride (st-PCN*) as both the photocatalyst and carrier for chlorperoxidase (CPO). 178 Under irradiation, the obtained st-PCN*@CPO composite could realize the cascade chlorination reaction of monochlorodimedone into dichlordimedone driven by st-PCN*-catalyzed water photooxidation and H 2 O 2 photogeneration. The continuous bioconversion illustrates the great potential of the O 2 /H 2 O 2 cycle in coupling APS's cascade reactions.…”

“…166 A recent research has proven H 2 O 2 as a potential alternative to NAD(P)H for photoexcited electron delivery. 178 Its further development, however, depends on the solution for overwhelming the negative effects of H 2 O 2 on the enzyme system. In addition, as compared with NAD(P)H-dependent oxidoreductases, NAD(P)H-independent oxidoreductases can be activated directly with low electron loss; hence, they are suitable for easy integration into photocatalysts for high-performance system construction.…”

Enhanced Photobiocatalytic Cascades at Pickering Droplet Interfaces

“…Photobiocatalysis is emerging as an advanced synthetic technology for green chemical synthesis because it allows to integrate of the unique reactivity of photocatalysts and the superior selectivity of enzymes for the solar to chemical energy conversions. − By cascading photocatalysts with enzymes, several important chemical transformations, including photocatalytic regeneration of cofactor for CO 2 reduction, − biocatalytic oxidations with photogenerated H 2 O 2 , − and enantioselective hydroxylation/amination of C–H bond, − have been developed. Despite significant progress, highly reactive oxygen species produced over photocatalysts may damage the molecular structure of enzymes and then seriously deactivate them.…”

Mesoporous Carbon Nitride with π-Electron-Rich Domains and Polarizable Hydroxyls Fabricated via Solution Thermal Shock for Visible-Light Photocatalysis

“…10,11 Therefore, narrowing semiconductor bandgaps will strengthen the Coulomb interaction between photoinduced electrons and holes, thus decreasing the dissociation efficiency and concurrently increasing the probability of backward recombination. 12,13 Methods developed to extend the inherent optical absorption of carbon nitride include geometry engineering, 14,15 elemental doping, 16,17 donor−acceptor copolymerization, 18,19 and vacancy formation, 20,21 generating structures that show expanded photoresponsive range, but exhibit restricted exciton dissociation and unsatisfactory visible-light photoactivity. Recent advances are the ability to infuse π-rich conjugated aromatic domains into carbon nitride by replacing nitrogen with carbon considering the larger valence electron of carbon than that of nitrogen.…”

“…Methods developed to extend the inherent optical absorption of carbon nitride include geometry engineering, , elemental doping, , donor–acceptor copolymerization, , and vacancy formation, , generating structures that show expanded photoresponsive range, but exhibit restricted exciton dissociation and unsatisfactory visible-light photoactivity. Recent advances are the ability to infuse π-rich conjugated aromatic domains into carbon nitride by replacing nitrogen with carbon considering the larger valence electron of carbon than that of nitrogen. , However, feasible routes enabling carbon replacement are relatively limited, owing to the marked energetic barrier induced by the lower electronegativity of carbon than that of nitrogen, irreversible phase separation between components of large lattice mismatch, and different onset/platform pyrolysis temperatures between monomers. , To overcome these issues, supramolecular assembly and copolymerization are frequently performed, , in which molecules with π-rich skeletons and/or monomers with structures resembling precursors of carbon nitride are typically involved.…”