Enzyme-Photo-Membrane Artificial Photosynthetic System

Enzyme-photo-coupled catalytic system（EPCCSs）integrate the advantages of enzymatic and photocatalytic process.Compared with chemical catalyst-photo-coupled and microorganism-photo-coupled artificial photosynthetic systems,EPCCSs exert unique advantages of mild reaction conditions,designable reaction pathways as well as easy-to-parse mechanism and emerge as a frontier direction of green biomanufacturing technology.This study introduced membrane as a bridge between enzyme catalysis and photocatalysis,proposing a new idea of constructing enzyme-photo-membrane artificial photosynthetic systems.Based on"four effects"of microcapsular membrane,such as confinement effect,proximity effect,compartmentalization effect and channeling effect,a photo-membrane catalytic system,an enzyme-membrane catalytic system and an enzyme-photo-membrane artificial photosynthetic system were constructed,respectively.The method of coordinating the enzymatic and photocatalytic process through the microcapsular membrane was explored.The coordination mechanism between electron-proton-molecule transfer and catalytic reaction as well as the mass-energy coupled relationship were revealed,which realized the efficient conversion of solar energy to chemical energy.Construction of a photo-membrane catalytic system based on"confinement-channeling effect"and synergistic enhancement of electron-proton transfer process:the photo-membrane catalytic system was constructed by the hetero-conductive conjugated organic polymer membrane through the solvothermal method.The influence law of the monomer ratio and monomer type on the electron transfer as well as proton transfer in microcapsular membrane was explored.The influence mechanism of"confinement effect"and"channeling effect"on photocatalytic cofactor regeneration activity was revealed.The cofactor regeneration yield of the system was 97.0±2.6%,which was one of the highest values reported in the literature.Construction of an enzyme-membrane catalytic system based on"proximity-channeling effect"and enhancement of substrate molecule transfer process:the enzyme-membrane catalytic system was constructed by the enzyme immobilized zeolite imidazolate framework with hierarchical porous structure through polyphenol chemistry method.The influence law of the hierarchical porous structure on the substrate molecule transfer was explored.The influence mechanism of"proximity effect"and"channeling effect"on the enzymatic activity was revealed.Compared with the unoptimized system,the enzyme-membrane catalytic system improved both the enzymatic activity and enzyme stability by 1.5-8 times.Construction of an enzyme-photo-membrane artificial photosynthetic system based on"compartmentalization-channeling effect"and enhancement of cofactor molecule transfer process:the enzyme-photo-membrane artificial photosynthetic system was constructed by cadmium sulfide quantum dots photocatalyst,alcohol dehydrogenase and porous titanium dioxide microcapsule membrane through the biomimetic mineralization method.The influence laws of light,photocatalyst,free radicals and other environmental factors on the structure and function of enzyme,as well as the enzyme-photocatalyst distance on the shuttling behavior of cofactor molecule were explored.The influence mechanism of"compartmentalization effect"and"channeling effect"on enzyme-photocatalyst compatibility as well as catalytic activity of the system was revealed.The solar-to-chemical efficiency of the system was 0.69±0.12%,and the turnover frequency of the system reached 37635.2 h^-1,which was an order of magnitude higher than other reported EPCCSs.