Application of PickeringIL emulsion microreactor constructed based on temperature-sensitive double-enzyme Janus sphere to enhanced catalysis of conversion of CO2 into formic acid

Abstract

The invention discloses a Pickering IL emulsion microreactor constructed on the basis of temperature-sensitive double-enzyme Janus spheres and application of the Pickering IL emulsion microreactor to enhanced catalysis of conversion of CO2 into formic acid. A Janus emulsion template method is combined with a photocuring technology to synthesize a nano-scale dual-functional temperature-sensitive Janus sphere, one half of the nano-scale dual-functional temperature-sensitive Janus sphere is a hydrophilic hydrocarbon polymer, the other half of the nano-scale dual-functional temperature-sensitive Janus sphere is a hydrophobic fluorocarbon polymer, and rapid inversion of a Pickering emulsion can be realized by utilizing temperature sensitivity. The method comprises the following steps: preparing a Janus particle hydrophilic / hydrophobic hemisphere, selectively immobilizing formate dehydrogenase FDH and carbonic anhydrase CA on the Janus particle hydrophilic / hydrophobic hemisphere to obtain a temperature-sensitive FDH-Janus-CA composite sphere, introducing a fluorine-functionalized ionic liquid to regulate and control the internal microenvironment of a microreactor, and constructing a Pickering IL emulsion microreactor. The CO2 absorption capacity is increased by 47 times compared with that of a pure water system, the formic acid yield reaches 27.5 mM and is higher than the maximum value 22.8 mM of current enzyme electrocatalysis, the storage and catalysis stability is good, and an efficient and sustainable scheme is provided for CO2 recycling.

Description

Technical Field

[0001] This invention belongs to the field of functional materials, specifically relating to the construction of a PickeringIL emulsion microreactor based on temperature-sensitive dual-enzyme Janus spheres and its application in enhancing the catalytic conversion of CO2 to formic acid. Background Technology

[0002] Pickering emulsion systems, with their high interfacial surface area, excellent confinement ability, and ease of separation and recycling, overcome the mass transfer limitations of traditional two-phase catalytic systems and demonstrate significant value in microreactor design. By forming a physical barrier through the irreversible adsorption of solid particles at the interface, their high desorption energy barrier effectively inhibits emulsion aggregation, Ostwald ripening, and phase separation, providing a new approach for constructing long-lasting and stable reaction interfaces.

[0003] As the most significant greenhouse gas, CO2's surge in concentration exacerbates the greenhouse effect, triggering a series of climate crises such as global warming, glacial melting, and frequent extreme weather events, posing a major challenge to human sustainable development. Catalytic conversion technology, which transforms CO2 into valuable chemical raw materials such as methane, methanol, carbon monoxide, formic acid, low-carbon olefins, and aromatic hydrocarbons, can not only effectively reduce atmospheric carbon emissions but also provide a sustainable carbon source for the chemical industry.

[0004] Currently, CO2 capture and resource utilization have become cutting-edge research directions in the fields of green chemistry and sustainable energy. Ionic liquids (ILs) have shown great application potential in the field of CO2 capture due to their designable molecular structures, low volatility, and excellent gas solubility. Therefore, constructing a PickeringIL emulsion microreactor based on temperature-sensitive dual-enzyme Janus spheres and studying its application in the CO2 conversion process is a key task. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention constructs a Pickering IL microreactor system based on the fluorinated ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6). This design utilizes the unique CO2 affinity of BMIMPF6 to create a locally high-concentration enrichment zone within the micro-reaction interface, effectively overcoming the mass transfer limitations of traditional systems. Furthermore, the precise interfacial anchoring effect of the FDH-Janus-CA composite spheres stabilizes the IL / water biphase interface while significantly enhancing the anti-demulsification ability of the emulsion system, achieving long-term stable operation of the reaction system. This synergistic mechanism not only ensures a continuous supply of substrate but also significantly improves the cascade catalytic efficiency of formate dehydrogenase (FDH) and carbonic anhydrase (CA) through micro-interface effects. This microreactor system exhibits excellent cycle stability while maintaining high catalytic activity, providing a new approach for developing efficient and sustainable CO2 resource recovery technologies.

[0006] To achieve the above-mentioned technical objectives, the present invention employs the following technical means:

[0007] The present invention first prepared a temperature-sensitive Janus sphere. The temperature-sensitive Janus sphere is spherical with a relatively obvious dividing line on the outer side of the sphere. One side of the dividing line is a hydrophilic hemisphere and the other side is a hydrophobic hemisphere.

[0008] This invention provides a method for preparing the temperature-sensitive Janus ball, specifically including the following steps:

[0009] (1) The crosslinkable thermosensitive hydrocarbon polymer PEG-b-PABP-bP (NIPAM-co-GMA) of hydrocarbon polymer PEANG was dissolved in 1,4-dioxane solvent and labeled as the H phase.

[0010] Simultaneously, the crosslinkable fluorocarbon polymer P (FMA-co-GMA-co-ABP) of fluorocarbon polymer PFAG was dissolved in 1H,1H,2H,2H-perfluorodecyl acrylate and labeled as phase F;

[0011] The H phase, F phase, free radical photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173) and 1,6-hexanediol diacrylate (HDDA) are thoroughly mixed in proportion to form a dispersed phase;

[0012] Fluorinated surfactant (Capstone FS-31) and sodium dodecyl sulfate (SDS) were dissolved in deionized water to obtain a continuous phase forming an emulsion system.

[0013] The dispersed phase was added to the continuous phase and homogenized to obtain a Janus emulsion;

[0014] (2) Janus emulsion was cured by irradiation under ultraviolet light. After the reaction was completed, it was centrifuged, washed, and freeze-dried to obtain bifunctional thermosensitive Janus spheres. The hydrocarbon polymer PEANG was a hydrophilic hemisphere and the fluorocarbon polymer PFAG was a hydrophobic hemisphere.

[0015] Preferably, in step (1), the preparation steps of the hydrocarbon polymer PEANG and the fluorocarbon compound PFGA include:

[0016] S1. In an aqueous solution of potassium hydroxide, carbon disulfide, 3-mercaptopropionic acid, and benzyl bromide are added dropwise with stirring. The mixture is then heated to reflux using a condenser. Once the reaction is complete, the product is the chain transfer agent 3-(benzylthiocarbonylthioalkyl)propionic acid (BSPA).

[0017] S2. Chain transfer agent 3-(benzylthiocarbonylthioalkyl)propionic acid (BSPA) and polyethylene glycol methyl ether (PEG) 45 -OH), N,N'-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) were added sequentially to dichloromethane, and the reaction was completed to obtain the macromolecular chain transfer agent PEG-CTA;

[0018] S3. The macromolecular chain transfer agent PEG-CTA, glycidyl methacrylate (GMA), isopropyl acrylamide (NIPAM) and initiator azobisisobutyronitrile (AIBN) were dissolved in 1,4-dioxane, and after ultrasonic dissolution, the reaction was carried out under nitrogen protection to obtain the thermosensitive block polymer PEG-bP (NIPAM-co-GMA).

[0019] S4. Dissolve PEG-bP (NIPAM-co-GMA), AIBN and the photocurable monomer 4-acryloyloxybenzophenone (ABP) in 1,4-dioxane solvent, sonicate to dissolve, and then react under nitrogen protection to obtain the crosslinkable thermosensitive block polymer PEG-b-PABP-bP (NIPAM-co-GMA), abbreviated as PEANG;

[0020] S5. GMA, BSPA, AIBN, ABP and 2-(perfluorooctyl)ethyl methacrylate (FMA) are dissolved in trifluorotoluene, and after ultrasonic acceleration of dissolution, they are reacted under nitrogen protection to obtain a photocurable fluorocarbon compound P (FMA-co-GMA-co-ABP), abbreviated as PFGA.

[0021] In step S1, the ratio of potassium hydroxide aqueous solution, 3-mercaptopropionic acid, carbon disulfide, and benzyl bromide is 32 mL: 2.5 mL: 4.5 mL: 5.5 g, wherein the concentration of potassium hydroxide aqueous solution is 1.8 mol / L; the reflux reaction is carried out under the condition of stirring in an oil bath at 85°C for 12 h.

[0022] In step S2, BSPA and PEG 45 The ratio of -OH, DCC, DMAP, and dichloromethane is 0.545g:2g:0.83g:49mg:20mL; the reaction conditions are a 25°C oil bath with continuous stirring for 48 hours.

[0023] In step S3, the ratio of 1,4-dioxane solvent, PEG-CTA, GMA, NIPAM, and AIBN is 8 mL: 0.24 g: 0.142 g: 1.358 g: 9 mg; the reaction conditions are: stirring in an oil bath at 75°C under nitrogen for 24 hours.

[0024] In step S4, the ratio of PEG-bP (NIPAM-co-GMA), AIBN, 4-acryloyloxybenzophenone (ABP), and 1,4-dioxane solvent is 0.68 g: 6 mg: (0.02 g ~ 0.1 g): 6 mL; the reaction is carried out under the following conditions: 75 °C oil bath with continuous stirring for 12 hours.

[0025] In step S5, the ratio of BSPA, 2-(perfluorooctyl)ethyl methacrylate (FMA), ABP, GMA, AIBN, and trifluorotoluene is 0.0256g:1.7g:0.25g:0.142g:9mg:12mL; the reaction conditions are: sealed under nitrogen atmosphere, reaction at 70°C in an oil bath for 12 hours.

[0026] Preferably, in the dispersed phase of step (1), the ratio of PEANG solution, PFGA solution, and free radical photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173) and 1,6-hexanediol diacrylate (HDDA) is 70 μL:30 μL:50 μL:10 μL, wherein the mass percentage concentrations of PEANG solution and PFGA solution are 7% and 0.5%, respectively.

[0027] In the continuous phase, the concentration ranges of SDS and FS-31 were 5–15 mg / mL and 20–40 mg / mL, respectively.

[0028] The ratio of dispersed phase to continuous phase is 160 μL: 1 mL.

[0029] Preferably, in step (2), the curing conditions under ultraviolet light are: irradiation under a 50W ultraviolet light for 60 to 90 minutes.

[0030] This invention also prepared thermosensitive dual-enzyme Janus spheres, namely thermosensitive FDH-Janus-CA composite spheres. The thermosensitive Janus spheres immobilize formate dehydrogenase and carbonic anhydrase in specific regions, achieving dual functionality, specifically including:

[0031] (A1) Formate dehydrogenase FDH hydrophilic region fixation:

[0032] FDH was dissolved in a phosphate buffer solution, and bifunctionalized thermosensitive Janus spheres were dispersed in vegetable oil. After mixing, the mixture was placed in a constant temperature water bath and allowed to stand. After vortex emulsification, a W / O type emulsion was prepared and then cured at a constant temperature to fix FDH specifically to the hydrophilic hemispheres of the Janus spheres, thus obtaining thermosensitive FDH-Janus composite spheres.

[0033] (A2) Immobilization of the hydrophobic region of carbonic anhydrase CA:

[0034] After emulsifying the thermosensitive FDH-Janus composite spheres obtained in step (A1), the emulsion was cooled and demulsified. Then, CA was added and reverse vortex emulsification was carried out to form an O / W type emulsion. Subsequently, it was solidified at a constant temperature to achieve the positioning and fixation of CA on the hydrophobic hemisphere of the Janus sphere. Finally, the organic phase was removed by centrifugation and the spheres were washed several times with phosphate buffer to obtain the thermosensitive FDH-Janus-CA composite spheres, which are immobilized by two enzyme partitions.

[0035] In steps A1 and A2, the ratio of FDH, phosphate buffer solution, bifunctionalized thermosensitive Janus ball, vegetable oil, and CA is 10 mg: 0.5 mL: 30 mg: 0.5 mL: 5 mg.

[0036] In step A1, the concentration of the phosphate buffer solution is 50 mM and the pH is 7.0.

[0037] In step A1, the temperature of the constant temperature water bath is 50℃, and the standing time is 5 minutes; the rotation speed of the vortex emulsification is 3000 r / min, and the time is 3 minutes; the temperature of the constant temperature curing is 30℃, and the time is 30 minutes.

[0038] In step A2, the demulsification temperature is 10℃; the reverse vortex emulsification speed is 3000 r / min and the time is 3 min; the isothermal curing temperature is 20℃ and the time is 30 min.

[0039] This invention also provides a Pickering IL microreactor system based on the fluorinated ionic liquid BMIMPF6. Utilizing the unique CO2 affinity of BMIMPF6, a localized high-concentration enrichment zone is formed within the microreaction interface, overcoming the mass transfer limitations of traditional systems. Furthermore, the precise interfacial anchoring effect of the FDH-Janus-CA composite spheres stabilizes the IL / water biphase interface while significantly enhancing the anti-demulsification ability of the emulsion system, achieving long-term stable operation of the reaction system. It can significantly improve the cascade catalytic efficiency of formate dehydrogenase (FDH) and carbonic anhydrase (CA).

[0040] The application of temperature-sensitive dual-enzyme Janus spheres in constructing Pickering IL emulsion microreactors to absorb CO2 and catalyze the conversion of CO2 to formic acid includes the following steps:

[0041] The temperature-sensitive dual-enzyme Janus, namely FDH-Janus-CA complex spheres, were dispersed in phosphate buffer according to a certain ratio to obtain FDH-Janus-CA complex sphere phosphate buffer. Then, 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (BMIMPF6-IL) was added, followed by emulsification treatment using intermittent shaking to prepare O / W type Pickering IL emulsion. Subsequently, NADH was added, and the mixture was transferred to a round-bottom flask. N2 was continuously bubbled through the flask to remove other gases, and then CO2 gas was continuously introduced at the same flow rate. The reaction was carried out under a sealed environment at a constant temperature, and the formic acid content was determined.

[0042] The volume ratio of the phosphate buffer to the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid in the FDH-Janus-CA composite spheres is 50:1.

[0043] The ratio of FDH-Janus-CA complex spheres, phosphate buffer, and NADH is 60 mg: 2 mL: 20 mM.

[0044] The phosphate buffer solution has a concentration of 50 mM and a pH of 7.0.

[0045] The intermittent oscillation method is as follows: manually oscillate for 20 seconds, then let it stand still for 10 seconds, and repeat 3 times.

[0046] The N2 is introduced and bubbled continuously for 5-10 minutes; the constant temperature reaction time is 1-2 hours.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0048] (1) Based on the Janus emulsion template method combined with photocuring technology, bifunctional thermosensitive Janus spheres with strict affinity-relativity region separation structure were prepared. The continuous and reversible phase inversion of Pickering emulsion was realized through temperature response characteristics, which broke through the limitations of spatial isolation and positioning of incompatible catalysts and provided an interface carrier for the spatial partitioning and fixation of multiple enzymes.

[0049] (2) Using bifunctional thermosensitive Janus spheres and fluorine-functionalized ionic liquid BMIMPF6, a Pickering IL emulsion microreactor with CO2 enrichment and high-efficiency catalysis was designed. The microenvironmental regulation capability of the ionic liquid was used to increase the CO2 concentration in the reactor. At the same time, the stable emulsion interface provided long-term protection for the enzyme, realizing the efficient synergy of CO2 enrichment and catalysis and improving the formic acid generation efficiency. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the synthetic route for the crosslinkable thermosensitive hydrocarbon polymer PEG-b-PABP-bP (NIPAM-co-GMA).

[0051] Figure 2 This is a schematic diagram of the synthetic route for crosslinkable fluorocarbon polymer P (FMA-co-ABP-co-GMA).

[0052] Figure 3 This is a schematic diagram of the synthesis process for bifunctional temperature-sensitive Janus spheres.

[0053] Figure 4 The images show the infrared spectra of the intermediate and final products of each polymer, as well as Janus spheres.

[0054] Figure 5 The images show the 1H NMR spectra of the intermediate and final products of each polymer.

[0055] Figure 6 The morphology of emulsions stabilized by compound surfactants composed of different concentrations of SDS and FS-31.

[0056] Figure 7 SEM (a), EDS (b), and dynamic laser light scattering (c) images of Janus particles at 15 °C are shown.

[0057] Figure 8 Contact angles (a) of hydrocarbon polymer PEG-b-PABP-bP (NIPAM-co-GMA) at 15°C; (b) of fluorocarbon polymer P (FMA-co-ABP-co-GMA); (c) of Janus ball at 15°C; and (d) of Janus ball at 35°C.

[0058] Figure 9 Macroscopic images of Janus sphere-stabilized Pickering emulsion (a, b), optical electron microscope images (c, d), and inverted fluorescence microscope images (e, f).

[0059] Figure 10 Images taken with an inverted fluorescence microscope of W / O type Pickering emulsion immobilized FDH (a) and O / W type Pickering emulsion immobilized CA (b).

[0060] Figure 11 A schematic diagram of the dual-functional temperature-sensitive Janus sphere with immobilized FDH and CA.

[0061] Figure 12XPS spectra of (a) Janus spheres and FDH-Janus-CA composite spheres; high resolution (b) N 1s spectra, (c) C 1s spectra, (d) O 1s spectra, and (e) F 1s spectra.

[0062] Figure 13 This is a laser confocal image of a temperature-sensitive FDH-Janus-CA composite sphere.

[0063] Figure 14 Photographs and optical microscope images of emulsions of BMIMPF6 ionic liquid stabilized by FS-31 and bifunctional thermosensitive Janus spheres; (b) comparison of the emulsion state of BMIMPF6 ionic liquid stabilized by Janus spheres.

[0064] Figure 15 The emulsification of Janus sphere suspensions of different concentrations with ionic liquids at different volume ratios is shown.

[0065] Figure 16 (a) Optical microscopy image, (b) SEM image, and (c) inverted fluorescence microscopy image of Pickering IL emulsion stabilized by bifunctionalized thermosensitive Janus spheres.

[0066] Figure 17 The absorption capacity of the Pickering IL emulsion microreactor for H2-Ar mixed gas and CO2 gas is given.

[0067] Figure 18 (a) The absorption capacity of deionized water and IL / W emulsion for CO2 gas and (b) its change over time.

[0068] Figure 19 Comparison of formic acid concentration generated by (a) Pickering CO2 bubble system and Pickering IL emulsion system constructed with FDH-Janus-CA composite spheres; (b) Change in formic acid concentration generated by CO2 catalyzed by Pickering IL emulsion microreactor over time.

[0069] Figure 20 This is a schematic diagram illustrating the mechanism of the Pickering IL emulsion microreactor catalyzing the conversion of CO2 to formic acid. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0071] Example 1

[0072] (1) Preparation of crosslinkable thermosensitive hydrocarbon polymer PEG-b-PABP-bP (NIPAM-co-GMA)

[0073] (S1) Preparation of the chain transfer agent 3-(benzylthiocarbonylthioalkyl)propionic acid (BSPA) The synthetic steps of the chain transfer agent benzyl trithiocarbonate (BSPA) are as follows: Figure 1 As shown in (a). Potassium hydroxide (KOH, 3.3 g, 59 mmol) was weighed into a single-necked round-bottom flask, and 32 mL of deionized water was added. The mixture was stirred continuously until completely dissolved. Then, 3-mercaptopropionic acid (C3H6O2S, 2.5 mL, 28.5 mmol) and carbon disulfide (CS2, 5 mL, 82.8 mmol) were added dropwise with stirring. When the solution turned orange-red, the reaction was carried out at 25 °C for 5 hours. After the reaction was complete, benzyl bromide (C7H7Br, 5.5 g, 32.2 mmol) was slowly added dropwise to the flask over 1 hour. After the addition was complete, a condenser was installed, and the oil bath temperature was raised to 85 °C. The reaction was continued for 12 hours. After the reaction was complete, the mixture was cooled to room temperature, and appropriate amounts of chloroform and hydrochloric acid were added. The solution gradually separated into layers. The upper layer was removed, and the lower layer was washed repeatedly with distilled water until it became clear. The lower layer solution after washing was subjected to rotary evaporation at 45°C to remove most of the solvent. Two to three drops of dichloromethane were added to the remaining solution, and the mixture was sealed and frozen in a refrigerator. After crystallization, the product was filtered and washed with water to obtain a yellow powdery crude BSPA product. Subsequently, after two cycles of dissolving in chloroform, vacuum distillation, freezing, filtration, and washing with water, the product was transferred to a vacuum drying oven at 30°C and dried for 36 hours to obtain high-purity BSPA.

[0074] (S2) Preparation of macromolecular chain transfer agent (PEG-CTA)

[0075] The synthetic steps of macromolecular chain transfer (PEG-CTA) are as follows: Figure 1 As shown in (b). Weigh out the chain transfer agent (BSPA, 0.545 g, 2 mmol) and polyethylene glycol methyl ether (PEG). 45In a round-bottom flask, dissolve 2 g (1 mmol) of N,N'-dicyclohexylcarbodiimide (DCC, 0.83 g, 4 mmol) and 4-dimethylaminopyridine (DMAP, 49 mg, 0.4 mmol) in 20 mL of dichloromethane. Slowly add this mixture dropwise to the flask over 1 hour. After the addition is complete, raise the reaction temperature to 25 °C and stir continuously for 48 hours. After the reaction is complete, remove the insoluble salts from the reaction solution by vacuum filtration and collect the filtrate for vacuum distillation. Slowly add the resulting oily product dropwise to excess ice-cold anhydrous diethyl ether. After the precipitate has completely formed, filter the precipitate. Repeat the process of dissolving in dichloromethane, vacuum distillation, precipitation with anhydrous diethyl ether, and filtration twice. Finally, the product was transferred to a vacuum drying oven at 30°C and dried for 36 hours to obtain a high-purity, pale yellow solid product, PEG-CTA.

[0076] (S3) Preparation of thermosensitive block polymer PEG-bP (NIPAM-co-GMA)

[0077] The synthesis steps of the thermosensitive block polymer PEG-bP (NIPAM-co-GMA) are as follows: Figure 1 As shown in (c). First, the macromolecular chain transfer agent PEG-CTA (0.24 g, 0.1 mmol), isopropylacrylamide (NIPAM, 1.358 g, 12 mmol), glycidyl methacrylate (GMA, 0.142 g, 1 mmol), and the initiator azobisisobutyronitrile (AIBN, 9 mg, 54 μmol) were fully dissolved in 8 mL of 1,4-dioxane solvent and added to a single-necked round-bottom flask. Nitrogen gas was bubbled continuously for 30 minutes, followed by vacuum for 10 minutes to remove oxygen from the reaction system. The reaction system was then placed in a constant-temperature oil bath and stirred continuously at 75 °C for 24 hours, maintaining a nitrogen atmosphere throughout the process. After the reaction was completed, the round-bottom flask was rapidly cooled in an ice-water bath to quench the reaction. After diluting the reaction product with a small amount of 1,4-dioxane, the product was slowly added dropwise to an excess of cold anhydrous diethyl ether for precipitation and centrifugation. The precipitate was redissolved in 1,4-dioxane solvent, precipitated again with ice-cold anhydrous diethyl ether, and centrifuged to obtain a preliminarily purified pale yellow solid product. The solid product was vacuum dried at 60°C for 12 hours, dissolved in deionized water to prepare an aqueous solution, dialyzed (MWCO: 10 kDa) for 24 hours, and then freeze-dried to obtain the thermosensitive block polymer PEG-bP (NIPAM-co-GMA).

[0078] (S4) Preparation of crosslinkable thermosensitive block polymer PEG-b-PABP-bP (NIPAM-co-GMA)

[0079] PEG-bP (NIPAM-co-GMA) (0.68 g, 63.6 μmol), acryloyloxybenzophenone (ABP, 0.02 g, 79 μmol; 0.06 g, 238 μmol; 0.1 g, 396 μmol), and the initiator azobisisobutyronitrile (AIBN, 6 mg, 36 μmol) were weighed and completely dissolved by sonication in 6 mL of 1,4-dioxane solvent. The mixed solution was continuously purged with nitrogen for 30 minutes, evacuated by vacuum pump for 10 minutes, sealed under nitrogen atmosphere, and placed in an oil bath at 75 °C with continuous stirring for 12 hours. After the reaction was completed, the flask was quickly placed in ice water to quench the reaction, and then the reaction solution was slowly added dropwise to an excess of ice-cold anhydrous diethyl ether until a white solid precipitated. The solid product was collected by centrifugation. Finally, the product was dissolved twice in 1,4-dioxane solvent, precipitated with ice-cold anhydrous diethyl ether, and centrifuged. It was then placed in a vacuum drying oven at 60°C overnight. The resulting white solid was the crosslinkable thermosensitive block polymer PEG-b-PABP-bP (NIPAM-co-GMA). The synthesis steps are as follows: Figure 1 As shown in (d).

[0080] (2) Preparation of crosslinkable fluorocarbon polymer P (FMA-co-ABP-co-GMA)

[0081] Weigh the chain transfer agent (BSPA, 0.0256 g, 1 mmol), 2-(perfluorooctyl)ethyl methacrylate (FMA, 1.7 g, 3.2 mmol), 4-acryloyloxybenzophenone (ABP, 0.25 g, 1 mmol), glycidyl methacrylate (GMA, 0.142 g, 1 mmol), and the initiator azobisisobutyronitrile (AIBN, 9 mg, 54 μmol) into a round-bottom flask. Add 12 mL of trifluorotoluene solvent and sonicate until the solids are completely dissolved. Purge the solution with nitrogen gas and bubble continuously for 30 minutes. After evacuation for 10 minutes, seal the flask under nitrogen atmosphere and place it in an oil bath at 70 °C for 12 hours. After the reaction is complete, place the flask in ice water to terminate the reaction. Slowly add the reaction solution dropwise to excess n-hexane, and obtain the crude solid product by precipitation and centrifugation. Finally, the product was subjected to two cycles of trifluorotoluene dissolution, n-hexane precipitation, and centrifugation, and then dried overnight in a vacuum drying oven at 60°C to obtain the crosslinkable fluorocarbon polymer P (FMA-co-GMA-co-ABP), abbreviated as PFAG. The synthesis steps are as follows: Figure 2 As shown.

[0082] (3) Preparation of Janus emulsion and bifunctionalized temperature-sensitive Janus beads

[0083] like Figure 3As shown, the dispersed phase was prepared as follows: the hydrocarbon polymer PEANG was dissolved in a 1,4-dioxane solvent (7 wt%), labeled as phase H. Simultaneously, the fluorocarbon polymer PFAG was dissolved in 1H,1H,2H,2H-perfluorodecyl acrylate (0.5 wt%), labeled as phase F. 70 μL of phase H, 30 μL of phase F, 50 μL of the photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173), and 10 μL of 1,6-hexanediol diacrylate (HDDA) were thoroughly mixed.

[0084] Continuous phase preparation: Different concentrations of the anionic surfactant sodium dodecyl sulfonate (SDS) and the fluorinated surfactant (Capstone FS-31) were dissolved in deionized water.

[0085] Emulsion preparation: 160 μL of dispersed phase was added to 1 mL of continuous phase, and emulsified at 3000 r / min for 1 minute to obtain a uniform Janus emulsion;

[0086] Preparation of bifunctional temperature-sensitive Janus spheres: The prepared Janus emulsion was transferred to a water bath circulating reactor and cured with a 50W UV lamp for 1.5 hours. After curing, the product was washed multiple times with deionized water, the supernatant was removed by centrifugation, and then freeze-dried to obtain bifunctional temperature-sensitive Janus spheres.

[0087] The infrared spectra of each intermediate and product in the examples are as follows: Figure 4 As shown, by Figure 4As shown in (a), in the FT-IR spectrum of BSPA, the OH and C=O stretching vibration peaks of the carboxyl group are at 3031 cm⁻¹ and 1700 cm⁻¹, respectively; the CH stretching vibration peaks of the methylene and methine groups on the benzene ring and the stretching vibration peak of the benzene ring skeleton appear at 2917 cm⁻¹ and 1495 cm⁻¹, respectively; and the C=S stretching vibration peak of the trithiocarbonate appears at 1073 cm⁻¹. In the FT-IR spectrum of the macromolecular chain transfer agent PEG-CTA, the OH absorption peak of the carboxyl group at 3031 cm⁻¹ disappears, and the C=O stretching vibration absorption peak shows a red shift (1734 cm⁻¹). At the same time, new CH stretching and bending vibration absorption peaks appear at 2885 cm⁻¹ and 1467 cm⁻¹, indicating that the terminal group (-COOH) of CTA has undergone an esterification reaction, and PEG-CTA has been successfully synthesized. In the FT-IR spectrum of the block polymer PENG, the epoxy group absorption peaks of glyceryl methacrylate (GMA) appeared at 910 cm⁻¹ and 840 cm⁻¹; the CN, C=O, and NH stretching vibration peaks of the amide group of N-isopropylacrylamide (NIPAM) appeared at 1541 cm⁻¹, 1652 cm⁻¹, and 3312 cm⁻¹, respectively; and the CH stretching vibration peak of the isopropyl tertiary carbon and the bending vibration peak of the methyl group appeared at 2974 cm⁻¹ and 1387 cm⁻¹, respectively, indicating the successful synthesis of the block polymer PENG. Figure 4 As shown in (b), compared to PENG, PEANG exhibits the characteristic absorption peak of the benzene ring in acryloyloxybenzophenone (ABP) at 838-925 cm⁻¹, indicating the successful introduction of the ABP structural unit. Meanwhile, the FT-IR spectrum of PFAG shows that the asymmetric stretching vibration peak, symmetric stretching vibration peak, and bending vibration peak of -CF₂ appear at 1205 cm⁻¹, 1245 cm⁻¹, and 703 cm⁻¹, respectively; the characteristic absorption peaks of the ester carbonyl C=O and unsaturated double bond C=C appear at 1733 cm⁻¹ and 1655 cm⁻¹, respectively; the characteristic absorption peaks of single and double substitution of the benzene ring appear at 838-925 cm⁻¹; and the characteristic absorption peak of the epoxy group appears at 838 cm⁻¹. These characteristic peaks all indicate the successful polymerization of FMA, ABP, and GMA. Comparing the FT-IR spectra of PEANG and PFAG, the Janus sphere retains the characteristic absorption peaks of PEANG and PFAG, indicating the successful preparation of the bifunctionalized temperature-sensitive Janus sphere.

[0088] Figure 5 The following are the 1H NMR spectra of the intermediates and products, and BSPA. 1 HNMR spectrum ( Figure 5In A), the characteristic peaks at chemical shifts of 7.27–7.41 ppm (standard a), 4.68 ppm (standard b), 3.57 ppm (standard c), and 2.71 ppm (standard d) are attributed to Ph-H, Ph-CH2, -CH2-S-, and -CH2–C=O, respectively, confirming the successful synthesis of BSPA. PEG-CTA 1 In the 1H NMR spectrum, a characteristic peak of the PEG repeating unit -CH2CH2O- appears at chemical shifts of 3.43-3.70 ppm (e), indicating that the carboxyl group of CTA forms a covalent bond with the hydroxyl group on PEG-OH through an esterification reaction, yielding the target product PEG-CTA. (PENG) 1 H NMR spectrum ( Figure 5 B) shows that the peaks at chemical shifts of 1.04 ppm (g), 1.43 ppm (k), and 1.95 ppm (j) are attributed to the proton peaks of -CH3, -CH2-, and ≡CH in PNIPAM and GMA, respectively. Proton peaks of -CH(CH3)2 and -CO-NH- in PNIPAM appear at chemical shifts of 3.51 ppm (h) and 7.24 ppm (i). Chemical shifts of 3.84 ppm and 4.27 ppm (l) correspond to the proton peaks of the methylene group adjacent to the epoxy group in GMA, confirming the successful synthesis of polymer PENG. 1 H NMR ( Figure 5 B) indicates that the multiplet at chemical shifts of 6.88-7.95 ppm (standard m) corresponds to the proton peak of the benzene ring in ABP, indicating the successful introduction of the ABP monomer.

[0089] PFAG 1 H NMR such as ( Figure 5 As shown in C), the multiplet at chemical shifts of 7.47-7.84 ppm (label a) corresponds to the proton peak of the benzene ring in ABP; chemical shifts of 3.76 ppm and 4.27 ppm (label b) correspond to the proton peak of the methylene group adjacent to the epoxy group in GMA; chemical shift of 2.46 ppm (label c) corresponds to the absorption peak of -CH2CH2CF2- on FMA; chemical shifts of 1.45 ppm (label d) and 1.97 ppm (label e) correspond to the proton peaks of -CH2- and ≡CH on the main chain, respectively; and chemical shift of 1.10 ppm (label f) corresponds to the proton peak of -CH3 in FMA and GMA, proving the successful synthesis of the fluorocarbon polymer PFAG.

[0090] In summary, in this embodiment, crosslinkable thermosensitive hydrocarbon polymer PEG-b-PABP-bP (NIPAM-co-GMA), crosslinkable fluorocarbon polymer P (FMA-co-ABP-co-GMA), Janus emulsion, and bifunctionalized thermosensitive Janus spheres were successfully prepared.

[0091] Figure 6 The images show the stable emulsion morphology of a complex surfactant composed of SDS and FS-31 at different concentrations. When the SDS concentration is 5 mg / mL, as the FS-31 concentration increases from 20 mg / mL to 40 mg / mL, the emulsion topology successively undergoes transformations from H < F / W to H|F / W and then to H / F / W. When the SDS concentration is increased to 10 mg / mL, the topological evolution path is the same. At an SDS / FS-31 ratio of 10 / 30 mg / mL, the H|F / W droplets exhibit uniform particle size and complete structure due to the equilibrium of interfacial tension between the two phases, representing the optimal preparation condition. Further increasing the SDS concentration to 15 mg / mL causes excess SDS to induce interfacial competitive adsorption, leading to a topological evolution from F / H / W to H|F / W and then back to F < H / W. When the ratio is 10 / 30 mg / mL, the H|F / W type emulsion formed exhibits a clear and stable two-phase interface and has strictly symmetrical hemispherical hydrophilic / hydrophobic partitions, thus it can be used for photocuring to obtain Janus spheres.

[0092] Figure 7 (a) shows the SEM observation results. This figure clearly shows that the Janus nanospheres prepared by ultrasonic emulsification still retain the same clear H|F phase boundary separation as those prepared by vortex emulsification. EDS elemental analysis ( Figure 7 (b) further confirms that the rough hemisphere (H phase) is enriched in N, while the smooth hemisphere (F phase) is dominated by F, verifying the chemical heterogeneity of the Janus structure. Dynamic light scattering test ( Figure 7 (c) shows that the average hydration dynamic diameter of Janus spheres prepared by vortex emulsification is 8627 nm, while ultrasonic emulsification reduces the particle size to 943 nm, a reduction of 89%.

[0093] Figure 8 This diagram shows the contact angles at different temperatures. At 15°C, PEANG (H phase) exhibits a contact angle of 61.40° due to the dominance of hydrophilic amide groups in the NIPAM chain, while PFAG (F phase) reaches a contact angle of 109.90° due to the strong hydrophobic effect of fluorine atoms. The Janus spheres formed by the combination of the two have a contact angle of 89.22° in equilibrium, close to the theoretical ideal value of 90°. After heating to 35°C (above LCST), the contact angle of the Janus spheres increases to 134.14°.

[0094] Figure 9 (a, b) indicates that when the oil / water volume ratio is 2:8, an oil-in-water (O / W) emulsion is formed, and the fluorocarbon oil droplets settle at the bottom of the aqueous phase due to density differences; when the volume ratio is adjusted to 8:2, it transforms into a water-in-oil (W / O) emulsion, and the aqueous phase droplets accumulate at the top of the oil phase. Figure 9Images (c, d) show that the Janus spheres exhibit a highly ordered and dense arrangement at the oil-water interface, forming a continuous protective layer. Fluorescence microscopy characterization of the aqueous phase using FITC labeling was employed. Figure 9 As shown in (e, f), the droplets of both O / W and W / O emulsions maintained their intact morphology, and no dispersed phase droplets appeared in the continuous phase, confirming that the emulsion system has excellent interfacial integrity.

[0095] Application example:

[0096] Formate dehydrogenase and carbonic anhydrase were immobilized in separate compartments of bifunctional thermosensitive Janus spheres to prepare thermosensitive dual-enzyme Janus spheres, namely FDH-Janus-CA composite spheres.

[0097] A1: Formate dehydrogenase (FDH) hydrophilic region fixation:

[0098] 10 mg of FDH was dissolved in 0.5 mL of phosphate buffer solution (50 mM, pH 7.0), while 30 mg of bifunctionalized thermosensitive Janus spheres were dispersed in 0.5 mL of vegetable oil. The mixture was placed in a 50°C water bath and allowed to stand for 5 minutes. Then, it was vortexed at 3000 rpm for 3 minutes to prepare a W / O emulsion. Finally, it was cured at 30°C for 30 minutes to specifically immobilize FDH onto the hydrophilic hemispheres of the thermosensitive Janus spheres, thus obtaining thermosensitive FDH-Janus composite spheres.

[0099] A2 carbonic anhydrase (CA) hydrophobic region immobilization:

[0100] After emulsifying the thermosensitive FDH-Janus composite spheres, the resulting emulsion was cooled to 10°C to break the emulsion. Then, 5 mg of CA was added, and the mixture was vortexed in reverse (3000 rpm, 3 min) to form an O / W emulsion. Subsequently, the emulsion was fixed at 20°C for 30 min to achieve the localization and immobilization of CA on the hydrophobic hemispheres of the Janus spheres. Finally, the organic phase was removed by centrifugation, and the spheres were washed three times with phosphate buffer to obtain the thermosensitive FDH-Janus-CA composite spheres, a dual-enzyme regional immobilization product.

[0101] Figure 10The results show that in the W / O emulsion system (a), without the addition of thermosensitive Janus spheres, FITC-labeled FDH is uniformly distributed within the water droplets (approximately 190 μm in diameter). After the introduction of thermosensitive Janus spheres, the droplet diameter shrinks to 100 μm, and yellow-green fluorescence is significantly enriched in the interfacial region. This fluorescence migration from the bulk phase to the interface confirms that FDH is selectively immobilized on the hydrophilic hemispheres of the Janus spheres. In contrast, in the O / W emulsion system (b), without the addition of FDH-Janus spheres, RhBITC-labeled CA exhibits a diffuse distribution within the oil droplets (approximately 200 μm in diameter). After the addition of FDH-Janus particles, the oil droplet diameter shrinks to 145 μm, and red fluorescence forms a characteristic ring-shaped interfacial distribution, confirming that CA is selectively immobilized on the hydrophobic hemispheres of the Janus spheres.

[0102] Figure 11 This is a mechanism diagram of the partitioning and immobilization of FDH and CA in a bifunctional thermosensitive Janus sphere, proving that a thermosensitive FDH-Janus-CA composite sphere has been obtained.

[0103] Figure 12 XPS analysis and characterization Figure 13 The laser confocal microscopy images showed that green fluorescence (FITC-FDH) and red fluorescence (RhBITC-CA) appeared in two different hemispherical regions of the Janus sphere with clear partitioning. This phenomenon strictly corresponds to the functional partitioning of the hydrophilic / hydrophobic hemispheres of the Janus sphere, confirming that the precise partitioning and immobilization of the two enzymes by the Janus particles has been achieved. FDH is preferentially immobilized in the hydrophilic CH hemisphere through aqueous phase wetting, while CA is oriented and immobilized in the hydrophobic CF hemisphere after phase inversion in the emulsion. The thermosensitive FDH-Janus-CA composite sphere was successfully prepared.

[0104] For comparison, a Pickering IL emulsion microreactor was first constructed based on bifunctionalized temperature-sensitive Janus spheres.

[0105] This experiment employed an intermittent oscillation method (manual oscillation for 20 seconds followed by 10 seconds of rest, repeated 3 times) to emulsify and prepare an O / W type Pickering IL emulsion. 10 mg of bifunctional thermosensitive Janus spheres were mixed with 1 mL of phosphate buffer (50 mM, pH 7.0) and dispersed by ultrasonication to prepare a thermosensitive Janus sphere suspension. The suspension was incubated in a 10°C water bath for 5 minutes, and then 20 μL of 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (BMIMPF6-IL) was added, resulting in a volume ratio of phosphate buffer to 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (BMIMPF6-IL) of 50:1.

[0106] Figure 14Figure (a) shows the BMIMPF6 ionic liquid stained with Sudan IV. The comparison revealed that while the FS-31 surfactant could emulsify IL into micron-sized droplets, insufficient emulsion stability led to significant droplet aggregation within 10 minutes. In contrast, the bifunctional thermosensitive Janus spheres, through tight interfacial adsorption, formed a stable O / W-type picking IL emulsion, and no droplet aggregation was observed under optical microscopy. This confirms that the bifunctional thermosensitive Janus spheres can not only successfully construct picking IL emulsion microreactors but also maintain emulsion structural stability. Comparative analysis of Figure (b) in Figure 14 shows that in cases of emulsification failure, the ionic liquid severely adhered to the walls, and no emulsion layer appeared at the bottom; in cases of successful emulsification, no wall adhesion occurred, and a thick bottom emulsion layer was formed.

[0107] Figure 15 To systematically observe the effect of the volume ratio of bifunctionalized thermosensitive Janus spheres to intraluminal (IL) on emulsification by preparing suspensions of different concentrations, experiments showed that under a fixed volume ratio of 100:2 (v / v) for bifunctionalized thermosensitive Janus sphere suspension to IL, only 2 mg / mL of Janus spheres was required to form a stable emulsion system. The emulsion volume reached saturation when the Janus sphere concentration was increased to 10 mg / mL. When the volume ratio increased to 100:3 (v / v), the Janus sphere concentration required to maintain emulsion stability significantly increased to 10 mg / mL. In conclusion, this experiment used a 10 mg / mL Janus sphere suspension with IL at a volume ratio of 100:2 (v / v) for emulsification, ensuring emulsion stability while also being economical.

[0108] Figure 16The morphology of Pickering IL emulsion was analyzed using a combination of optical microscopy and scanning electron microscopy (SEM). Optical microscopy image (a) shows that bifunctionalized thermosensitive Janus spheres are densely adsorbed at the IL / W interface, forming uniformly dispersed spherical Pickering IL emulsion droplets. SEM characterization (b) further reveals that the Pickering IL emulsion droplets maintain a complete spherical structure (average diameter 10 μm), and the surface exhibits micro-roughness due to the encapsulation of bifunctionalized thermosensitive Janus spheres. The stable structure under vacuum pressure confirms its excellent mechanical strength. To further elucidate the interfacial behavior, multi-channel imaging was performed using a FITC / RhBITC dual-fluorescence microscope combined with an inverted fluorescence microscope. As shown in Figure (c), both bright-field and fluorescence images confirm the spherical characteristics of the Pickering IL emulsion droplets (average diameter 10 μm), and the specific anchoring of the bifunctionalized thermosensitive Janus spheres at the IL / W interface, which is highly consistent with the optical microscopy observations. The above results indicate that the bifunctional temperature-sensitive Janus spheres effectively prevent droplet coalescence through irreversible interfacial adsorption, and their unique directional anchoring effect and interfacial stabilization ability together endow Pickering IL emulsion with long-lasting anti-coalescence properties.

[0109] Application of bifunctional thermosensitive dual-enzyme Janus sphere-stabilized IL / W emulsion for selective absorption and conversion of CO2 gas into formic acid.

[0110] This step assesses the CO2 absorption performance of the emulsion system by weighing the mass change before and after CO2 absorption. 60 mg of FDH-Janus-CA composite spheres were dispersed in 2 mL of phosphate buffer (50 mM, pH 7.0), followed by the addition of 40 μL of 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (BMIMPF6-IL), resulting in a 50:1 volume ratio of FDH-Janus-CA composite spheres in phosphate buffer to 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid. Emulsification was then performed using intermittent shaking (20 seconds of manual shaking followed by 10 seconds of resting, repeated 3 times) to prepare an O / W type Pickering IL emulsion. Subsequently, 20 mM NADH (26.56 mg) was added, and the mixture was transferred to a round-bottom flask. N2 was bubbled continuously for 5-10 minutes to purge other gases, followed by continuous bubbling of CO2 gas at the same flow rate. The mixture was then reacted at a constant temperature in a sealed environment for 1-2 hours. After the reaction was completed, the mixture was allowed to stand for 10 minutes, and the amount of formic acid produced was detected by HPLC.

[0111] Figure 17The results show that the maximum absorption capacity of the IL / W emulsion for the H2-Ar mixed gas is 46.92 mg H2-Ar / g IL, while its absorption capacity for pure CO2 reaches 172.31 mg CO2 / g IL, which is 3.67 times that of the former. Therefore, the CO2 absorption capacity of the IL / W emulsion is significantly better than that of the H2-Ar mixed gas, proving that the IL / W emulsion can selectively absorb CO2 gas.

[0112] Figure 18 The CO2 absorption capacity of the pure water system and the IL / W emulsion system was compared. Figure (a) shows that the maximum CO2 absorption capacity of deionized water was only 3.59 mg CO2 / g H2O, while the maximum absorption capacity of the IL / W emulsion reached 172.31 mg CO2 / g IL, approximately 47 times higher than that of the pure water system. Furthermore, Figure (b) shows that the CO2 absorption rate of the IL / W emulsion rapidly increased and reached equilibrium within the initial 3 minutes, while the absorption capacity of the pure water system remained below 3.6 mg CO2 / g H2O for 9 minutes. This demonstrates that the Janus sphere-stabilized IL / W emulsion can significantly enhance the CO2 absorption rate and strengthen CO2 enrichment within the microenvironment system.

[0113] Figure 19 As shown in Figure (a), the formic acid concentration produced by the Pickering CO2 bubble system was 21.0 mM, while the Pickering IL emulsion system reached 27.5 mM, representing a 31% increase in yield. As shown in Figure (b), the formic acid concentration rapidly increased to 20.27 mM within the initial 10 min, then the rate of increase slowed, reaching a maximum of 27.5 mM at 120 min. However, when the reaction time was extended to 140 min, the formic acid concentration dropped back to 26.5 mM, a decrease of 3.6%.

[0114] Figure 20 This is a schematic diagram of the catalytic enhancement mechanism of the Pickering IL emulsion microreactor enzyme. The system selectively absorbs and stores CO2 through an ionic liquid phase (with an absorption capacity of 172.31 mg CO2 / g IL). Subsequently, the CA catalyzes the conversion of the captured CO2 into HCO3-, which diffuses through the interface to the CH hemispherical surface of the Janus particles. The immobilized FDH then completes the formic acid synthesis and NADH oxidation processes.

[0115] Therefore, the introduced O / W type Pickering IL emulsion microreactor provides a simple and efficient method for the absorption of CO2 and its conversion into formic acid.

[0116] In summary, the thermosensitive FDH-Janus-CA composite spheres and their stable Pickering ionic liquid (IL) emulsion microreactor prepared by this invention demonstrate highly efficient synergy between CO2 enrichment and catalysis, thereby improving the formic acid generation efficiency and exhibiting great practicality.

[0117] The embodiments described herein are preferred embodiments of the present invention. All other embodiments obtained by those skilled in the art without making any obvious improvements, substitutions or modifications are within the scope of protection of the present invention.

Claims

1. A method for preparing a temperature-sensitive Janus ball, characterized in that, Includes the following steps: (1) The crosslinkable thermosensitive hydrocarbon polymer PEG-b-PABP-bP (NIPAM-co-GMA) of hydrocarbon polymer PEANG was dissolved in 1,4-dioxane solvent and labeled as phase H; Simultaneously, the crosslinkable fluorocarbon polymer P (FMA-co-GMA-co-ABP) of fluorocarbon polymer PFAG was dissolved in 1H,1H,2H,2H-perfluorodecyl acrylate and labeled as phase F; The H phase, F phase, free radical photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1,6-hexanediol diacrylate (HDDA) are thoroughly mixed in proportion to form a dispersed phase. The fluorinated surfactant Capstone FS-31 and sodium dodecyl sulfate (SDS) were dissolved in deionized water to obtain a continuous phase that forms an emulsion system. The dispersed phase was added to the continuous phase and homogenized to obtain a Janus emulsion; (2) Janus emulsion was cured by irradiation under ultraviolet light. After the reaction was completed, it was centrifuged, washed, and freeze-dried to obtain bifunctional thermosensitive Janus spheres. The hydrocarbon polymer PEANG was a hydrophilic hemisphere and the fluorocarbon polymer PFAG was a hydrophobic hemisphere.

2. The method for preparing the temperature-sensitive Janus ball as described in claim 1, characterized in that, In the dispersed phase of step (1), the ratio of PEANG solution, PFGA solution, free radical photoinitiator 2-hydroxy-2-methyl-1-phenyl-1-propanone and 1,6-hexanediol diacrylate HDDA is 70 μL:30 μL:50 μL:10 μL, wherein the mass percentage concentrations of PEANG solution and PFGA solution are 7% and 0.5%, respectively. In the continuous phase, the concentration ranges of SDS and FS-31 were 5–15 mg / mL and 20–40 mg / mL, respectively. The ratio of dispersed phase to continuous phase is 160 μL: 1 mL.

3. The method for preparing the temperature-sensitive Janus ball as described in claim 1, characterized in that, In step (2), the curing conditions under ultraviolet light are: irradiation under a 50W ultraviolet light for 60 to 90 minutes.

4. A method for preparing temperature-sensitive dual-enzyme Janus spheres, characterized in that, Includes the following steps: (A1) Formate dehydrogenase FDH hydrophilic region fixation: FDH was dissolved in a phosphate buffer solution, and bifunctionalized thermosensitive Janus spheres were dispersed in vegetable oil. After mixing, the mixture was placed in a constant temperature water bath and allowed to stand. After vortex emulsification, a W / O type emulsion was prepared and then cured at a constant temperature to fix FDH specifically to the hydrophilic hemispheres of the Janus spheres, thus obtaining thermosensitive FDH-Janus composite spheres. (A2) Immobilization of the hydrophobic region of carbonic anhydrase CA: After emulsifying the thermosensitive FDH-Janus composite spheres obtained in step (A1), the emulsion was cooled and demulsified. Then, CA was added and reverse vortex emulsification was carried out to form an O / W type emulsion. Subsequently, it was solidified at a constant temperature to achieve the positioning and fixation of CA on the hydrophobic hemisphere of the Janus sphere. Finally, the organic phase was removed by centrifugation and the spheres were washed several times with phosphate buffer to obtain the thermosensitive FDH-Janus-CA composite spheres, which are immobilized by two enzyme partitions.

5. The method for preparing temperature-sensitive dual-enzyme Janus spheres as described in claim 4, characterized in that, In steps A1 and A2, the ratio of FDH, phosphate buffer solution, bifunctionalized thermosensitive Janus ball, vegetable oil, and CA is 10 mg: 0.5 mL: 30 mg: 0.5 mL: 5 mg.

6. The method for preparing temperature-sensitive dual-enzyme Janus spheres as described in claim 4, characterized in that, In step A1, the concentration of the phosphate buffer solution is 50 mM and the pH is 7.0; The temperature of the constant temperature water bath is 50℃, and the standing time is 5 minutes; the rotation speed of the vortex emulsification is 3000 r / min, and the time is 3 minutes; the temperature of the constant temperature curing is 30℃, and the time is 30 minutes.

7. The method for preparing temperature-sensitive dual-enzyme Janus spheres as described in claim 4, characterized in that, In step A2, the demulsification temperature is 10℃; the reverse vortex emulsification speed is 3000 r / min and the time is 3 min; the isothermal curing temperature is 20℃ and the time is 30 min.

8. The use of temperature-sensitive dual-enzyme Janus spheres in the construction of Pickering IL emulsion microreactors to absorb CO2 and catalyze the conversion of CO2 into formic acid.

9. The use as described in claim 8, characterized in that, The specific steps include: The temperature-sensitive dual-enzyme Janus, namely FDH-Janus-CA complex spheres, were dispersed in phosphate buffer according to a certain ratio to obtain FDH-Janus-CA complex sphere phosphate buffer. Then, 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (BMIMPF6-IL) was added, followed by emulsification treatment using intermittent shaking to prepare O / W type Pickering IL emulsion. Subsequently, NADH was added, and the mixture was transferred to a round-bottom flask. N2 was continuously bubbled through the flask to remove other gases, and then CO2 gas was continuously introduced at the same flow rate. The reaction was carried out under a sealed environment at a constant temperature, and the formic acid content was determined.

10. The use as described in claim 9, characterized in that, The volume ratio of the phosphate buffer to the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid in the FDH-Janus-CA composite spheres is 50:

1. The ratio of FDH-Janus-CA complex spheres, phosphate buffer, and NADH is 60 mg: 2 mL: 20 mM. The phosphate buffer solution has a concentration of 50 mM and a pH of 7.

0. The intermittent oscillation method is as follows: manually oscillate for 20 seconds, then let it stand still for 10 seconds, and repeat 3 times. The N2 is introduced and bubbled continuously for 5-10 minutes; the constant temperature reaction time is 1-2 hours.

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