A method for photochemical regeneration of coenzyme nadh

Abstract

The application relates to a method for photochemically regenerating coenzyme NADH, which comprises the following steps: (1) mixing a g-C3N4 / UiO-66 composite photosensitizer and an electron mediator in a phosphate buffer solution by ultrasonic mixing, uniformly mixing the obtained mixed solution with an electron donor and NAD + , and obtaining a photocatalytic reaction stock solution; and (2) performing light treatment on the photocatalytic reaction stock solution obtained in the step (1), and obtaining the coenzyme NADH. The application adopts the composite photosensitizer g-C3N4 / UiO-66 to photochemically regenerate the coenzyme NADH, matches reasonable photocatalytic reaction conditions, significantly improves the regeneration efficiency of the coenzyme NADH, and has a simple synthesis method and low cost, and has wide application prospects in the aspect of biotransforming carbon dioxide into high-value compounds.

Description

TECHNICAL FIELD

[0001] The application relates to the field of photocatalysis, in particular to a method for photochemical regeneration of coenzyme NADH. BACKGROUND

[0002] Carbon dioxide, as one of the main components of greenhouse gases, has caused serious environmental problems such as global warming, glacier melting and sea level rise. It is of great significance to reduce carbon emissions by converting carbon dioxide into high-value compounds such as formic acid and methanol. The use of biological catalysts with mild conditions and high selectivity, such as formate dehydrogenase, formaldehyde dehydrogenase and alcohol dehydrogenase, can realize the green conversion of carbon dioxide. An important coenzyme, namely nicotinamide adenine dinucleotide (NADH), is required in the process of using biological catalysts. About 80% of the reactions catalyzed by oxidoreductases require NAD / NADH as a coenzyme. However, the high price of NADH restricts its development, so developing an efficient NADH regeneration method has great industrial potential.

[0003] At present, the methods for NADH regeneration can be divided into four categories, namely chemical method, electrochemical method, enzyme action and photocatalytic regeneration method. Among them, the photocatalytic regeneration method is attracting more and more attention because it can utilize abundant solar energy. The efficiency of NADH regeneration by photocatalytic regeneration method mainly comes from the precise arrangement and integration of electron donors, photosensitizers and electron mediators on the nanoscale to produce an electron transfer cascade. Specifically, the photosensitizer absorbs solar energy to generate excited electrons, which are transferred to the electron mediator, and the electron donor compensates for the electron depletion in the photosensitizer. The electron mediator transfers the photoexcited electrons for NADH regeneration, so the photosensitizer is the initiator of the entire photocatalytic regeneration system, and the efficient electron transfer chain is the key factor. Commonly used photosensitizers include metal semiconductors, inorganic semiconductors, organic dyes and metal-organic framework materials (MOF).

[0004] CN 114515581A discloses a doped CdS photocatalyst, which is a CdS photocatalyst doped with Fe, In, Ce, Cu or Te elements, which is used to catalytically reduce NAD + to NADH. The application also relates to a system for photocatalytic conversion of CO2 based on a doped CdS photocatalyst, which comprises: (1) a photocatalytic enzyme coupling bifunctional catalytic composite material formed by coupling a doped CdS photocatalyst and a carrier immobilized oxidoreductase; (2) NAD + is catalytically reduced to NADH under the action of the doped CdS photocatalyst; (3) CO2 is catalytically converted to high-value compounds such as formic acid or formaldehyde by using NADH as a coenzyme under the action of oxidoreductase. However, the preparation process of the doped metal ion photocatalyst is complex and is not suitable for industrial production.

[0005] MOF materials have attracted extensive attention in photocatalytic hydrogen evolution, photocatalytic degradation of organic pollutants in water and photocatalytic reduction of CO2 due to their large specific surface area, abundant active sites and structure-tunable characteristics. However, the photocatalytic performance of traditional MOF materials is seriously affected due to high charge recombination rate and limited light absorption capacity.

[0006] CN 108579787A discloses a preparation method of a heterojunction photocatalyst for NADH regeneration. First, melamine and cyanuric acid form a hexagonal prism melamine-cyanuric acid supramolecular complex through hydrogen bonding and π-π stacking in an aqueous phase, and the supramolecular complex is further crystallized by a hydrothermal method. The supramolecular CM is calcined at high temperature to prepare hollow tubular g-C3N4. Red phosphorus is deposited on the surface of the hollow g-C3N4 nanotube by high-temperature sublimation during the gas deposition process to generate g-C3N4 nanotube loaded with red phosphorus quantum dots. However, the catalyst needs a gas deposition step, and has defects such as uneven deposition and difficult to guarantee catalytic activity.

[0007] In view of the deficiencies of the prior art, there is an urgent need to provide a method for preparing simple and efficient coenzyme NADH regeneration. SUMMARY

[0008] The purpose of the present application is to provide a method for photochemical regeneration of coenzyme NADH, which uses a composite photosensitizer g-C3N4 / UiO-66 coupled with g-C3N4 and MOF material UiO-66 that can absorb visible light and has a narrow band gap, efficiently photocatalyzing the regeneration of coenzyme NADH, with a simple synthesis method and low cost, high efficiency of coenzyme NADH regeneration, and wide application prospects in the biological catalytic conversion of CO2 into high-value compounds.

[0009] To achieve the purpose of the present application, the following technical solutions are adopted:

[0010] The present application provides a method for photochemical regeneration of coenzyme NADH, which comprises the following steps:

[0011] (1) The g-C3N4 / UiO-66 composite photosensitizer and the electron mediator are mixed in a phosphate buffer solution by ultrasonic mixing, and the obtained mixture is uniformly mixed with an electron donor and NADH to obtain a photocatalytic reaction stock solution; +

[0012] (2) The photocatalytic reaction stock solution obtained in step (1) is subjected to light treatment to obtain the coenzyme NADH.

[0013] ​The method provided by the application overcomes the low photocatalytic activity of pure-phase MOF material UiO-66, and prepares a composite photosensitizer g-C3N4 / UiO-66 coupled with g-C3N4 and UiO-66 and having high photocatalytic activity, which is used for photocatalytic regeneration of coenzyme NADH, effectively widens the light absorption range of UiO-66, reduces the photoelectron-hole recombination rate, improves the charge transfer rate, significantly improves the photocatalytic NADH regeneration efficiency under reasonable photocatalytic reaction conditions, and has a simple synthesis method and low cost, and can be used in biocatalysis technology.

[0014] Preferably, the molar ratio of the g-C3N4 / UiO-66 composite photosensitizer to the electron mediator in step (1) is 1:(9-11), for example, can be 1:9, 1:9.5, 1:10, 1:10.5 or 1:11, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0015] Preferably, the molar ratio of the electron donor to the electron mediator in step (1) is 1:(0.9-1.1), for example, can be 1:0.9, 1:0.95, 1:1, 1:1.05 or 1:1.1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0016] Preferably, the molar ratio of the NAD + Preferably, the molar ratio of the NADH to the electron mediator in step (1) is 1:(4.9-5.1), for example, can be 1:4.9, 1:4.95, 1:5, 1:5.05 or 1:5.1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0017] Preferably, the amount of the phosphate buffer used in step (1) is 35-40 mL, for example, can be 35 mL, 36 mL, 37 mL, 38 mL or 40 mL, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0018] Preferably, the g-C3N4 / UiO-66 composite photosensitizer in step (1) is prepared by the following preparation method:

[0019] (a) mixing zirconium chloride, terephthalic acid and N,N-dimethylformamide to obtain a mixed solution;

[0020] (b) first ultrasonic mixing of a g-C3N4 dissolving solution and the mixed solution obtained in step (a), and then performing hydrothermal treatment and centrifugal treatment, and sequentially washing and vacuum drying the obtained solid phase to obtain the g-C3N4 / UiO-66 composite photosensitizer;

[0021] The g-C3N4 dissolving solution in step (b) is obtained by mixing g-C3N4 and N,N-dimethylformamide by second ultrasonic mixing.

[0022] The g-C3N4 / UiO-66 composite photosensitizer prepared by the hydrothermal method has the characteristics of wide light absorption range, fast photo-generated carrier transfer rate and high coenzyme NADH regeneration efficiency, and the preparation process is simple and easy to implement, and the g-C3N4 / UiO-66 composite photosensitizer has wide application prospects in the biological catalytic conversion of CO2 into high-value compounds such as formic acid and methanol.

[0023] Preferably, the molar ratio of zirconium chloride to terephthalic acid in step (a) is (0.9-1.1):1, for example, it can be 0.9:1, 0.95:1, 1:1, 1.05:1 or 1.1:1, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0024] Preferably, the liquid-solid ratio of N,N-dimethylformamide to the total amount of zirconium chloride and terephthalic acid in step (a) is (45-50) mL:1 g, for example, it can be 45 mL:1 g, 46 mL:1 g, 47 mL:1 g, 48 mL:1 g, 49 mL:1 g or 50 mL:1 g, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0025] Preferably, the mixing time in step (a) is 28-32 min, for example, it can be 28 min, 29 min, 30 min, 31 min or 32 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0026] Preferably, the first ultrasonic mixing time in step (b) is 58-62 min, for example, it can be 58 min, 59 min, 60 min, 61 min or 62 min, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0027] Preferably, the mass fraction of g-C3N4 in the g-C3N4 / UiO-66 composite photosensitizer is 10-20 wt%, for example, it can be 10 wt%, 12 wt%, 15 wt%, 18 wt% or 20 wt%, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0028] The proportion of g-C3N4 is too high, which is not conducive to the uniform dispersion of g-C3N4 in the solution, and ultimately affects the purity of the product, and the proportion of g-C3N4 is too low, which is not conducive to the improvement of the light absorption capacity of the composite photocatalyst.

[0029] Preferably, the liquid to solid ratio of N,N-dimethylformamide to g-C3N4 in the g-C3N4 dissolving solution of step (b) is (20-50) mL:1 g, for example, it can be 20 mL:1 g, 30 mL:1 g, 40 mL:1 g or 50 mL:1 g, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0030] Preferably, the time of the second ultrasonic mixing is 58-62 min, for example, it can be 58 min, 59 min, 60 min, 61 min or 62 min, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0031] Preferably, the temperature of the hydrothermal treatment of step (b) is 118-122℃, for example, it can be 118℃, 119℃, 120℃, 121℃ or 122℃, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0032] Preferably, the time of the hydrothermal treatment of step (b) is 23-25 h, for example, it can be 23 h, 23.5 h, 24 h, 24.5 h or 25 h, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0033] Preferably, the step of washing of step (b) comprises: washing the obtained solid phase with N,N-dimethylformamide and acetone alternately until the filtrate is colorless.

[0034] Preferably, the temperature of the vacuum drying of step (b) is 78-82℃, for example, it can be 78℃, 79℃, 80℃, 81℃ or 82℃, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0035] Preferably, the time of the vacuum drying of step (b) is 7-9 h, for example, it can be 7 h, 7.5 h, 8 h, 8.5 h or 9 h, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0036] Preferably, the time of the ultrasonic mixing of step (1) is 4-6 min, for example, it can be 4 min, 4.5 min, 5 min, 5.5 min or 6 min, but is not limited to the listed values, other values not listed in the value range are also applicable.

[0037] Preferably, the electron donor of step (1) comprises triethanolamine.

[0038] Preferably, the electron mediator of step (1) comprises [Cp*Rh(bpy)Cl2]COOH.

[0039] Preferably, the [Cp*Rh(bpy)Cl2]COOH is prepared by mixing [Cp*RhCl2]2, anhydrous methanol and 2,2'-bipyridine-5,5'-dicarboxylic acid to a light yellow clear suspension, then adding anhydrous ether to form a precipitate, and vacuum drying the precipitate to obtain the [Cp*Rh(bpy)Cl2]COOH.

[0040] Preferably, the liquid-solid ratio of the [Cp*RhCl2]2 and anhydrous methanol is (75-85) mL:1 g, for example, it can be 75 mL:1 g, 78 mL:1 g, 80 mL:1 g, 82 mL:1 g or 85 mL:1 g, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0041] Preferably, the liquid-solid ratio of the 2,2'-bipyridine-5,5'-dicarboxylic acid and anhydrous methanol is (100-105) mL:1 g, for example, it can be 100 mL:1 g, 101 mL:1 g, 102 mL:1 g, 103 mL:1 g or 105 mL:1 g, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0042] Preferably, the temperature at which the anhydrous ether is added is 4°C.

[0043] Preferably, the temperature of the vacuum drying is 80°C, and the time is 2 h.

[0044] Preferably, the temperature of the light irradiation treatment in step (2) is 25-35°C, for example, it can be 25°C, 28°C, 30°C, 32°C or 35°C, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0045] Preferably, the time of the light irradiation treatment in step (2) is 1-2 h, for example, it can be 1 h, 1.2 h, 1.5 h, 1.8 h or 2 h, but is not limited to the listed values, and other values not listed in the value range are also applicable.

[0046] Preferably, the light source used for the light irradiation treatment in step (2) is visible light or ultraviolet light.

[0047] Preferably, the light irradiation treatment in step (2) is carried out in an argon atmosphere.

[0048] Preferably, the light irradiation treatment in step (2) is carried out under the condition of circulating cooling water.

[0049] As a preferred technical solution of the method of the present application, the method comprises the following steps:

[0050] (1) ultrasonic mixing g-C3N4 / UiO-66 composite photosensitizer and electron mediator in phosphate buffer for 4-6 min, uniformly mixing the obtained mixture, triethanolamine and NAD + to obtain a photocatalytic reaction stock solution; the molar ratio of g-C3N4 / UiO-66 composite photosensitizer to electron mediator is 1:(9-11); the molar ratio of triethanolamine to electron mediator is 1:(0.9-1.1); the molar ratio of NAD + to electron mediator is 1:(4.9-5.1); the amount of phosphate buffer is 35-40 mL;

[0051] The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

[0052] (a) mixing zirconium chloride, terephthalic acid and N,N-dimethylformamide for 28-32 min to obtain a mixed solution; the molar ratio of zirconium chloride to terephthalic acid is (0.9-1.1):1; the liquid-solid ratio of N,N-dimethylformamide to the total amount of zirconium chloride and terephthalic acid is (45-50) mL:1 g;

[0053] (b) ultrasonic mixing g-C3N4 dissolving solution with the mixed solution obtained in step (a) for 58-62 min, then hydrothermal treatment at 118-122℃ for 23-25 h, centrifugal treatment, washing the obtained solid phase with N,N-dimethylformamide and acetone alternately until the filtrate is colorless, vacuum drying at 78-82℃ for 7-9 h to obtain the g-C3N4 / UiO-66 composite photosensitizer; the mass fraction of g-C3N4 in the g-C3N4 / UiO-66 composite photosensitizer is 10-20 wt%; the liquid-solid ratio of N,N-dimethylformamide to g-C3N4 in the g-C3N4 dissolving solution is (20-50) mL:1 g; the g-C3N4 dissolving solution is obtained by ultrasonic mixing g-C3N4 and N,N-dimethylformamide for 58-62 min;

[0054] The electron mediator is [Cp*Rh(bpy)Cl2]COOH, which is prepared by the following method:

[0055] Mixing [Cp*RhCl2]2, anhydrous methanol and 2,2'-bipyridine-5,5'-dicarboxylic acid to a suspension, which is light yellow and clear, then adding anhydrous ether at 4℃ to form a precipitate, and the obtained precipitate is dried at 80℃ under vacuum for 2h to obtain the [Cp*Rh(bpy)Cl2]COOH; the liquid-solid ratio of [Cp*RhCl2]2 and anhydrous methanol is (75-85)mL:1g; the liquid-solid ratio of 2,2'-bipyridine-5,5'-dicarboxylic acid and anhydrous methanol is (100-105)mL:1g;

[0056] (2) The photocatalytic reaction stock solution obtained in step (1) is treated with visible light or ultraviolet light at 25-35℃, under an argon atmosphere and with circulating cooling water for 1-2h to obtain the coenzyme NADH.

[0057] Compared with the prior art, the present application has the following beneficial effects:

[0058] The method provided by the present application overcomes the low photocatalytic activity of pure-phase MOF material UiO-66, and prepares a composite photosensitizer g-C3N4 / UiO-66 coupled with g-C3N4 and UiO-66, which has high photocatalytic activity and is used for photocatalytic regeneration of coenzyme NADH, effectively widens the light absorption range of UiO-66, reduces the recombination rate of photo-generated electrons and holes, improves the charge transfer rate, and combines with reasonable photocatalytic reaction conditions, so that the photocatalytic NADH regeneration efficiency can reach 61%, the synthesis method is simple and low in cost, and has wide application prospects in the aspect of bioconversion of CO2 into high-value compounds. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 is the FTIR spectrum of the g-C3N4 / UiO-66 photosensitizer provided by the embodiments 1 and 2 of the present application. DETAILED DESCRIPTION

[0060] The technical solutions of the present application are further illustrated by specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations on the present application.

[0061] In the following examples, NAD + Triethanolamine is purchased from Shanghai Aladdin Company; the light treatment is carried out in a quartz photocatalytic reaction kettle equipped with a CEL-S500 simulated sunlight xenon lamp light source system; the regeneration efficiency of coenzyme NADH is detected by an enzyme marker at 340nm and calculated by a standard curve.

[0062] Preparation Example 1

[0063] The preparation example provides a preparation method of an electron mediator [Cp*Rh(bpy)Cl2]COOH required in a photochemical regeneration coenzyme NADH process, and the preparation method comprises the following steps:

[0064] The [Cp*RhCl2]2, anhydrous methanol and 2,2'-bipyridine-5,5'-dicarboxylic acid are mixed to form a light yellow clear suspension, then anhydrous ether is added at 4°C to form a precipitate, and the obtained precipitate is dried at 80°C under vacuum for 2h to obtain the [Cp*Rh(bpy)Cl2]COOH; the liquid-solid ratio of the [Cp*RhCl2]2 and anhydrous methanol is 80mL:1g; and the liquid-solid ratio of the 2,2'-bipyridine-5,5'-dicarboxylic acid and anhydrous methanol is 100mL:1g.

[0065] Example 1

[0066] The example provides a method for photochemical regeneration of coenzyme NADH, and the method comprises the following steps:

[0067] (1) The g-C3N4 / UiO-66 composite photosensitizer and [Cp*Rh(bpy)Cl2]COOH are mixed in a phosphate buffer solution under ultrasonic for 5min, the obtained mixture is uniformly mixed with triethanolamine and NAD + H, to obtain a photocatalytic reaction stock solution; the molar ratio of the g-C3N4 / UiO-66 composite photosensitizer and [Cp*Rh(bpy)Cl2]COOH is 1:10; the molar ratio of the triethanolamine and [Cp*Rh(bpy)Cl2]COOH is 1:1; the molar ratio of the NAD + H and [Cp*Rh(bpy)Cl2]COOH is 1:5; and the amount of the phosphate buffer solution is 35mL;

[0068] The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following preparation method:

[0069] (a) The zirconium chloride, terephthalic acid and N,N-dimethylformamide are mixed for 30min to obtain a mixed solution; the molar ratio of the zirconium chloride and terephthalic acid is 1:1; and the liquid-solid ratio of the N,N-dimethylformamide and the total amount of the zirconium chloride and terephthalic acid is 45mL:1g;

[0070] (b) the first ultrasonic mixing g-C3N4 solution is mixed with the mixed solution obtained in step (a) for 60 min, and then is subjected to hydrothermal treatment at 120°C for 24 h and centrifugal treatment, and the obtained solid phase is washed with N,N-dimethylformamide and acetone alternately until the filtrate is colorless, and is vacuum dried at 80°C for 8 h to obtain the g-C3N4 / UiO-66 composite photosensitizer; the mass fraction of the g-C3N4 in the g-C3N4 / UiO-66 composite photosensitizer is 20 wt%; the liquid-solid ratio of N,N-dimethylformamide to g-C3N4 in the g-C3N4 solution is 20 mL:1 g; and the g-C3N4 solution is obtained by mixing g-C3N4 and N,N-dimethylformamide by the second ultrasonic mixing for 60 min;

[0071] The [Cp*Rh(bpy)Cl2]COOH is prepared by the preparation method provided in Preparation Example 1.

[0072] (2) The photocatalytic reaction stock solution obtained in step (1) is treated with visible light at 30°C under an argon atmosphere and with circulating cooling water for 2 h to obtain the coenzyme NADH.

[0073] The FTIR spectrum of the 20 wt%-g-C3N4 / UiO-66 composite photosensitizer is shown in Figure 1 FIG. 1, and the characteristic peaks at 1497 cm -1 , 1423 cm -1 and 1377 cm -1 are attributed to asymmetric and symmetric stretching changes of carboxyl groups, the characteristic peaks at 736 cm -1 and 651 cm -1 are attributed to Z-O stretching vibration, and the characteristic peaks at 1579 cm -1 and 1683 cm -1 are related to carbon-nitrogen bonds; and the regeneration efficiency of the coenzyme NADH is 61%.

[0074] Example 2

[0075] The present embodiment provides a method for photochemical regeneration of coenzyme NADH, which comprises the following steps:

[0076] (1) The g-C3N4 / UiO-66 composite photosensitizer and [Cp*Rh(bpy)Cl2]COOH are mixed by ultrasonic mixing in a phosphate buffer for 4 min, and the obtained mixed solution is uniformly mixed with triethanolamine and NAD + ; to obtain a photocatalytic reaction stock solution; the molar ratio of the g-C3N4 / UiO-66 composite photosensitizer to [Cp*Rh(bpy)Cl2]COOH is 1:9; the molar ratio of the triethanolamine to [Cp*Rh(bpy)Cl2]COOH is 1:0.9; and the molar ratio of the NAD +The molar ratio of [Cp*Rh(bpy)Cl2]COOH to the phosphate buffer is 1:4.9; the amount of the phosphate buffer is 40 mL;

[0077] The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

[0078] (a) mixing zirconium chloride, terephthalic acid and N,N-dimethylformamide for 32 min to obtain a mixed solution; the molar ratio of the zirconium chloride to the terephthalic acid is 0.9:1; the liquid-solid ratio of the N,N-dimethylformamide to the total amount of the zirconium chloride and the terephthalic acid is 50 mL:1 g;

[0079] (b) first ultrasonic mixing of the g-C3N4 dissolving solution and the mixed solution obtained in step (a) for 58 min, then hydrothermal treatment at 118℃ for 25 h, centrifugal treatment, washing of the obtained solid phase with N,N-dimethylformamide and acetone alternately until the filtrate is colorless, and vacuum drying at 78℃ for 9 h to obtain the g-C3N4 / UiO-66 composite photosensitizer; the mass fraction of the g-C3N4 in the g-C3N4 / UiO-66 composite photosensitizer is 10 wt%; the liquid-solid ratio of the N,N-dimethylformamide to the g-C3N4 in the g-C3N4 dissolving solution is 50 mL:1 g; the g-C3N4 dissolving solution is obtained by second ultrasonic mixing of g-C3N4 and N,N-dimethylformamide for 58 min;

[0080] The [Cp*Rh(bpy)Cl2]COOH is prepared by the preparation method provided in Preparation Example 1:

[0081] (2) the photocatalytic reaction stock solution obtained in step (1) is treated with visible light at 25℃ under an argon atmosphere and with circulating cooling water for 2 h to obtain the coenzyme NADH.

[0082] The FTIR spectrum of the 10wt%-g-C3N4 / UiO-66 composite photosensitizer is shown in Figure 1 The FTIR spectrum of the 10wt%-g-C3N4 / UiO-66 composite photosensitizer is shown in -1 The FTIR spectrum of the 10wt%-g-C3N4 / UiO-66 composite photosensitizer is shown in -1 The FTIR spectrum of the 10wt%-g-C3N4 / UiO-66 composite photosensitizer is shown in

[0083] Example 3

[0084] The method for photochemical regeneration of the coenzyme NADH provided in this example is different from that in Example 1 in that, in addition to adjusting the light treatment time in step (2) to 1 h, the rest is the same as in Example 1.

[0085] Due to the shorter light time, the degree of photocatalytic reaction is relatively reduced, and the regeneration efficiency of coenzyme NADH is 34%.

[0086] Example 4

[0087] The embodiment provides a method for photochemical regeneration of coenzyme NADH, which is different from example 2 in that, in addition to adjusting the light treatment time in step (2) to 1h, the rest is the same as example 2.

[0088] Due to the shorter light time, the degree of photocatalytic reaction is relatively reduced, and the regeneration efficiency of coenzyme NADH is 34%.

[0089] Comparative Example 1

[0090] The comparative example provides a method for photochemical regeneration of coenzyme NADH, which is different from example 1 in that, in step (1), the g-C3N4 / UiO-66 composite photosensitizer is replaced by a single UiO-66 photosensitizer with equal molar amount, and the rest is the same as example 1.

[0091] Due to the high charge recombination rate of the UiO-66 photosensitizer and the limited light absorption capacity, the photocatalytic performance of the UiO-66 photosensitizer is relatively reduced, and the regeneration efficiency of coenzyme NADH is only 10-20%.

[0092] In summary, the method provided by the application overcomes the low photocatalytic activity of the pure-phase MOF material UiO-66, and prepares the composite photosensitizer g-C3N4 / UiO-66 coupled by g-C3N4 and UiO-66 with high photocatalytic activity for photocatalytic regeneration of coenzyme NADH, effectively widens the light absorption range of UiO-66, reduces the photoelectron-hole recombination rate, improves the charge transfer rate, and matches the reasonable photocatalytic reaction conditions, so that the photocatalytic NADH regeneration efficiency can reach 61%, the synthesis method is simple and low in cost, and has wide application prospects in the field of biological conversion of CO2 into high-value compounds.

[0093] The above merely provides a specific implementation manner of the application, but the protection scope of the application is not limited to this, and the person skilled in the art should understand that any change or replacement within the technical scope disclosed by the application can be easily thought of by the person skilled in the art, and falls within the protection scope and disclosure scope of the application.

Claims

1. A method for photochemical regeneration of coenzyme NADH, characterized by, The method comprises the following steps: (1) The g-C3N4 / UiO-66 composite photosensitizer and the electron mediator [Cp*Rh(bpy)Cl2]COOH are mixed in a phosphate buffer solution by ultrasonic mixing, and the obtained mixture is uniformly mixed with an electron donor and NAD + to obtain a photocatalytic reaction stock solution; (2) The photocatalytic reaction stock solution obtained in step (1) is subjected to light treatment to obtain the coenzyme NADH; In step (1), the g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method: (a) Zirconium chloride, terephthalic acid and N,N-dimethylformamide are mixed to obtain a mixed solution; (b) The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method: The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method: The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method: The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

2. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

3. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

4. The method of claim 1, wherein, The NAD of step (1) + The molar ratio with the electron mediator is 1 : (4.9-5.1).

5. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

6. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

7. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

8. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

9. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

10. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

11. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

12. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

13. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

14. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

15. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

16. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

17. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method: The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

18. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

19. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

20. The method of claim 1, wherein, The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method:

21. 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The method of claim 1, wherein, The method comprises the following steps: (1) ultrasonic mixing g-C3N4 / UiO-66 composite photosensitizer and electron mediator in phosphate buffer for 4-6 min, uniformly mixing the obtained mixture with triethanolamine and NAD + to obtain a photocatalytic reaction stock solution; the molar ratio of g-C3N4 / UiO-66 composite photosensitizer to electron mediator is 1:(9-11); the molar ratio of triethanolamine to electron mediator is 1:(0.9-1.1); the molar ratio of NAD + to electron mediator is 1:(4.9-5.1); and the amount of phosphate buffer is 35-40 mL; The g-C3N4 / UiO-66 composite photosensitizer is prepared by the following method: (a) mixing zirconium chloride, terephthalic acid and N,N-dimethylformamide for 28-32 min to obtain a mixed solution; the molar ratio of the zirconium chloride to the terephthalic acid is (0.9-1.1):1; the liquid-solid ratio of the N,N-dimethylformamide to the total amount of the zirconium chloride and the terephthalic acid is (45-50) mL:1 g; (b) first ultrasonic mixing of a g-C3N4 dissolving solution and the mixed solution obtained in step (a) for 58-62 min, then hydrothermal treatment at 118-122 ℃ for 23-25 h, centrifugal treatment, washing of the obtained solid phase with N,N-dimethylformamide and acetone alternately until the filtrate is colorless, vacuum drying at 78-82 ℃ for 7-9 h to obtain the g-C3N4 / UiO-66 composite photosensitizer; the mass fraction of the g-C3N4 in the g-C3N4 / UiO-66 composite photosensitizer is 10-20 wt%; the liquid-solid ratio of the N,N-dimethylformamide to the g-C3N4 in the g-C3N4 dissolving solution is (20-50) mL:1 g; the g-C3N4 dissolving solution is obtained by second ultrasonic mixing of g-C3N4 and N,N-dimethylformamide for 58-62 min; The electron mediator is [Cp*Rh(bpy)Cl2]COOH, which is prepared by the following method: mixing [Cp*RhCl2]2, anhydrous methanol and 2,2'-bipyridine-5,5'-dicarboxylic acid until the suspension is light yellow and clear, then adding anhydrous ether until a precipitate is formed, vacuum drying the obtained precipitate to obtain the [Cp*Rh(bpy)Cl2]COOH; (2) the photocatalytic reaction stock solution obtained in step (1) is treated with visible light or ultraviolet light at 25-35 ℃, in an argon atmosphere and with circulating cooling water for 1.5-2 h to obtain the coenzyme NADH.

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