Method for regenerating NADH through electro-catalysis

Abstract

The invention relates to the field of electrocatalytic hydrogenation, in particular to an electrocatalytic NADH regeneration method. The method comprises the following steps that foamy copper serves as an anode, a platinum wire serves as a cathode, a KOH solution serves as an electrolyte, in-situ oxidation is conducted through a chronopotentiometry, washing is conducted through water and ethyl alcohol, vacuum drying is conducted, calcination is conducted in a tubular furnace, CuO nanowires are obtained, the CuO nanowires serve as the cathode, the platinum wire serves as the anode, in-situ reduction is conducted on the CuO nanowires through a chronoamperometry, and the Cu nanowires are obtained. Adding thioacetamide and acetic acid into the copper sulfate solution, stirring to obtain a reaction solution, adding the Cu nanowire and the reaction solution into a chemical bath deposition container, heating, washing and drying to obtain a CuxS nanowire; in an inert gas atmosphere, carrying out electrocatalysis on NAD < + > to regenerate 1, 4-NADH; in the step S4, the electric potential of the electro-catalysis is minus 1.1 V vs.Ag / AgCl to minus 1.25 V vs.Ag / AgCl. According to the method, the NADH can be generated by hydrogenation at the 1, 4 position in a high-efficiency and high-selectivity manner.

Description

Technical Field

[0001] The invention belongs to the field of electrocatalytic hydrogenation, and in particular relates to a method for electrocatalytic NADH regeneration. Background Art

[0002] Artificial photosynthesis is currently a hot research field for solving environmental and energy problems. The main process is to convert light energy into chemical energy by simulating natural photosynthesis. Its research areas are mainly concentrated in three major directions: water splitting, carbon dioxide (CO2) fixation, and coenzyme regeneration. Among them, coenzymes are the most widely used key factors in chemical catalytic applications. More than 80% of oxidoreductase catalytic reactions are related to them. There is a huge demand in industrial production and they have very important economic value and application value. However, the production and purification costs of coenzymes are extremely high, which greatly limits their wide application. How to reduce the cost of coenzyme production and improve production efficiency has become a key and critical issue in this field. The full name of the coenzyme NADH is reduced nicotinamide adenine dinucleotide. It is an auxiliary factor involved in cellular material and energy metabolism. In nature, it is mainly produced in glycolysis and cellular respiration in the citric acid cycle. As an important biological hydrogen carrier and electron donor, it participates in the oxidative phosphorylation process of the Calvin cycle in the inner membrane of the mitochondria. It participates in the synthesis of adenosine triphosphate (ATP) by supplying energy. It plays an important role in the process of biological enzyme catalysis and participates in most redox reactions in biological organisms. NADH and NAD + It is a redox pair in the cell operation, which undergoes oxidation and reduction reactions and converts into each other in the body. Under the premise that most technical processes are complex, costly, energy-intensive and polluting, electrocatalytic coenzyme regeneration is considered to be a promising green and clean regeneration method.

[0003] In 2022, Academician Li Can and his team from the Zhang Dayu College of Dalian University of Technology and the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences studied the electrocatalytic NADH regeneration and its reaction mechanism on metal and carbon electrodes. The bioactive 1,4-NADH was relatively selective on Cu, Fe and Co electrodes without forming the common NAD2 byproduct.

[0004] In summary, there is an urgent need to provide an efficient electrocatalytic method for selective hydrogenation to generate NADH at the 1,4 positions. Summary of the invention

[0005] The present invention aims to solve the problem of how to efficiently and selectively hydrogenate NADH at the 1,4 positions using an electrocatalytic method.

[0006] In order to achieve the above object, the present invention provides a method for electrocatalytic NADH regeneration in a first aspect, which comprises the following steps:

[0007] S1a: The copper foam was immersed in HCl solution, sonicated, rinsed with water and acetone, dried and placed in an argon atmosphere for later use;

[0008] S2a: Using the copper foam treated with S1 as the anode, platinum wire as the cathode, and KOH solution as the electrolyte, the copper foam was in situ oxidized by chronopotentiometry, washed with water and ethanol, dried in vacuum, and calcined in a tube furnace to obtain CuO nanowires. Using the CuO nanowires as the cathode and the platinum wire as the anode, the CuO nanowires were in situ reduced by chronoamperometry to obtain Cu nanowires.

[0009] S3a: Add thioacetamide to the copper sulfate solution, stir it for the first time, add acetic acid, stir it for the second time, obtain a reaction solution, add the Cu nanowires and the reaction solution into a chemical bath deposition container, heat it, wash it, and dry it to obtain Cu x S nanowire, wherein x is 1 to 2;

[0010] S4a: Cu x S nanowires were used as working electrodes, Pt sheets were used as counter electrodes, and Ag / AgCl electrodes were used as reference electrodes. Electrocatalysis of NAD + Regenerate 1,4-NADH;

[0011] or,

[0012] S1b: immerse the copper foam in HCl solution, sonicate, rinse with water and acetone, dry and place in argon atmosphere for later use;

[0013] S2b: The copper foam treated with S1 was used as the anode, the platinum wire as the cathode, and the KOH solution as the electrolyte. The copper foam was in situ oxidized by chronopotentiometry, washed with water and ethanol, dried in vacuum, and calcined in a tube furnace to obtain CuO nanowires.

[0014] S3b: Add thioacetamide to the copper sulfate solution, stir it for the first time, add acetic acid, stir it for the second time, obtain a reaction solution, add the CuO nanowires and the reaction solution into a chemical bath deposition container, heat it, wash it, and dry it to obtain Cu x S nanowire, wherein x is 1 to 2;

[0015] S4b: Cu x S nanowires were used as working electrodes, Pt sheets were used as counter electrodes, and Ag / AgCl electrodes were used as reference electrodes. Electrocatalysis of NAD + Regenerate 1,4-NADH;

[0016] Wherein, in S4a or S4b, the electrocatalytic potential is -1.1 to -1.25 V vs. Ag / AgCl.

[0017] The second aspect of the present invention provides Cu prepared by the above methodx S nanowires.

[0018] The third aspect of the present invention provides the above method or the above Cu x Application of S nanowires in electrocatalysis.

[0019] The beneficial effects of the present invention are as follows: the method provided by the present invention can generate NADH by hydrogenation at the 1,4 positions with high efficiency and selectivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The Cu prepared in Example 1 x Scanning electron microscope (SEM) image of S.

[0021] Figure 2 This is a scanning electron microscope (SEM) image of the Cu nanowires prepared in Example 1.

[0022] Figure 3 The foam copper, Cu nanowires, and Cu prepared in Example 1 x Comparison of the selectivity of S nanowires for NADH hydrogenation. DETAILED DESCRIPTION

[0023] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0024] A first aspect of the present invention provides a method for electrocatalytic NADH regeneration, comprising the following steps:

[0025] S1a: The copper foam was immersed in HCl solution, sonicated, rinsed with water and acetone, dried and placed in an argon atmosphere for later use;

[0026] S2a: Using the copper foam treated with S1 as the anode, platinum wire as the cathode, and KOH solution as the electrolyte, the copper foam was in situ oxidized by chronopotentiometry, washed with water and ethanol, dried in vacuum, and calcined in a tube furnace to obtain CuO nanowires. Using the CuO nanowires as the cathode and the platinum wire as the anode, the CuO nanowires were in situ reduced by chronoamperometry to obtain Cu nanowires.

[0027] S3a: Add thioacetamide to the copper sulfate solution, stir it for the first time, add acetic acid, stir it for the second time, obtain a reaction solution, add the Cu nanowires and the reaction solution into a chemical bath deposition container, heat it, wash it, and dry it to obtain Cu x S nanowire, wherein x is 1 to 2;

[0028] S4a: Cu x S nanowires were used as working electrodes, Pt sheets were used as counter electrodes, and Ag / AgCl electrodes were used as reference electrodes. Electrocatalysis of NAD + Regenerate 1,4-NADH;

[0029] or,

[0030] S1b: immerse the copper foam in HCl solution, sonicate, rinse with water and acetone, dry and place in argon atmosphere for later use;

[0031] S2b: The copper foam treated with S1 was used as the anode, the platinum wire as the cathode, and the KOH solution as the electrolyte. The copper foam was in situ oxidized by chronopotentiometry, washed with water and ethanol, dried in vacuum, and calcined in a tube furnace to obtain CuO nanowires.

[0032] S3b: Add thioacetamide to the copper sulfate solution, stir it for the first time, add acetic acid, stir it for the second time, obtain a reaction solution, add the CuO nanowires and the reaction solution into a chemical bath deposition container, heat it, wash it, and dry it to obtain Cu x S nanowire, wherein x is 1 to 2;

[0033] S4b: Cu x S nanowires were used as working electrodes, Pt sheets were used as counter electrodes, and Ag / AgCl electrodes were used as reference electrodes. Electrocatalysis of NAD + Regenerate 1,4-NADH;

[0034] Wherein, in S4a or S4b, the electrocatalytic potential is -1.1 to -1.25 V vs. Ag / AgCl.

[0035] In the present invention, copper sulfate is introduced as a copper source and a sulfur source, thioacetamide is used as a sulfur source and a complexing agent, and Cu is directly synthesized in one step under a relatively low temperature (below 100° C.). x S (x = 1-2) nanowires, the inventors found that thioacetamide contains an amine group that coordinates with Cu, which helps Cu at low temperatures x The synthesis of S, using thioacetamide (TA) as S 2- Cu was synthesized at room temperature via a microemulsion template route. x S nanoparticles.

[0036] In the present invention, thioacetamide is used as a monomer to combine with metal ions. In the Cu / thioacetamide system, the shear vibration frequency of -NH2 is significantly reduced, while the main CN stretching frequency remains unchanged. If the link between the thioacetamide molecule and the metal surface is through the S atom, the main contribution of the electronic structure will come from the resonance structure (IV). In this case, the order of the CS bond will be reduced, so the C—S stretching frequency is expected to be reduced. On the other hand, if the bonding is through the N atom, the expected result is the opposite. The introduction of the N atom reduces the energy required for the formation of the Cu-S bond, so that the sulfurization efficiency is higher and the Cu-S bond strength is greater.

[0037] In the present invention, the method of S3 promotes the low-temperature synthesis of copper sulfide nanowires.

[0038] In the present invention, the synthesis of the copper nanowire precursor is successful, so that the copper sulfide can maintain the morphology of the nanowire during formation. When CuO or Cu(OH)2 is used as a precursor, the sulfidation at this time will cause the Cu in the generated CuS nanowire to 2+ The ratio of Cu nanowires can be increased. + The proportion is relatively high, and currently in the field of hydrogenation reduction, Cu + Relative to Cu 2+ The effect is better.

[0039] According to the present invention, in S1a or S1b, the concentration of the HCl solution is 0.1-1 M, and the ultrasonic time is 5-10 min.

[0040] According to the present invention, in S2a or S2b, the concentration of the KOH solution is 2-5M.

[0041] According to the present invention, in S2a or S2b, the in-situ oxidation conditions include: the potential range of the in-situ oxidation is 0-2V, the current of the in-situ oxidation is 5-20mAcm -2 The reaction time of in-situ oxidation is 15-25min.

[0042] According to the present invention, in S2a or S2b, the vacuum drying conditions include: a drying temperature of 60-80°C.

[0043] According to the present invention, in S2a or S2b, the calcination conditions include: in an air atmosphere, a calcination temperature of 160-200° C., and a calcination time of 2-3 h.

[0044] According to the present invention, in S2a, the conditions for in-situ reduction include: the electrolyte is a PBS solution, the electrolyte pH is 6-8, the electrolyte concentration is 0.05-0.2M, the potential is -1.1 to -1.25Vvs.Ag / AgCl, and the power-on time is 10-20min.

[0045] According to the present invention, in S3a or S3b, the molar ratio of copper sulfate to thioacetamide is 1:0.4-0.6, and the molar ratio of copper sulfate to acetic acid is 1:0.2-0.5.

[0046] According to the present invention, in S3a or S3b, the first stirring time is 5-10 min, and the second stirring time is 5-10 min.

[0047] According to the present invention, in S3a or S3b, the heating conditions include: heating time is 1.5-2.5h, and heating temperature is 60-80°C.

[0048] According to the present invention, in S3a or S3b, the vacuum drying conditions include: a drying temperature of 60-70°C.

[0049] According to the present invention, in S34 or S34, the electrocatalytic conditions include: the substrate is reduced nicotinamide adenine dinucleotide disodium salt NAD + , Nicotinamide adenine dinucleotide disodium salt (NAD) + The concentration is 0.5-2 mM, the electrocatalytic pH is 6.8-7.2, and the electrocatalytic time is 60-120 min.

[0050] In the present invention, the highest 1,4-NADH regeneration selectivity was measured at pH = 7, and at pH = 8, due to the + The concentration is low, so the NADH regeneration speed is slow and the selectivity is not high enough. When pH = 6, the regeneration speed is fast due to the high concentration of hydrogen protons, but it is the high concentration that leads to the disorder of hydrogenation and produces a large amount of biologically inactive 1,6-NADH. Subsequently, at pH = 7, different potential tests were carried out. When the potential reached -1.3Vvs.Ag / AgCl, due to the HER process, a large amount of current was used in the hydrogen production process, resulting in lower selectivity and Faraday efficiency. When the potential was lower than -1.1Vvs.Ag / AgCl, the selectivity and speed of regeneration were lower than -1.2Vvs.Ag / AgCl.

[0051] The second aspect of the present invention provides Cu prepared by the above method x S nanowires.

[0052] The third aspect of the present invention provides the above method or the above Cu x Application of S nanowires in electrocatalysis.

[0053] Test Method

[0054] The electrochemical test was conducted by a three-electrode system. The reactor was an H-type electrolytic cell with a Nafion 117 diaphragm. The counter electrode was a Pt sheet (2 cm × 1 cm), the reference electrode was Ag / AgCl (saturated KCl), and all potentials were controlled by a CHI 660E electrochemical workstation. No iR compensation was performed during the test. The electrocatalytic NADH regeneration experiment was conducted by constant potential electrolysis.

[0055] The method for measuring the selectivity of electrocatalytic regeneration of 1,4-NADH is the glutamate dehydrogenase method, and the specific operation is as follows:

[0056] The amount of 1,4-NADH was measured by the conversion of glutamate into L-glutamate by reaction with α-ketoglutarate and ammonium sulfate catalyzed by glutamate dehydrogenase (GDH), in which the entire active 1,4-NADH formed during the electrolysis was consumed by the enzymatic reaction.

[0057] The preparation method of GDH solution is as follows: add 120 mg of ammonium sulfate, 20 mg of α-ketoglutaric acid, and 12 μL of glutamate dehydrogenase into 10 mL of 0.1 M PBS solution, dissolve and store in a refrigerator for later use.

[0058] In this reaction process, after reacting with the GDH solution (glutamate dehydrogenase + α-ketoglutarate + ammonium sulfate), 1,4-NADH is consumed and the absorbance at 340nm on the UV spectrum decreases. Therefore, based on the change in UV-Vis absorption at 340nm during the electrolysis process, the concentration of enzyme active 1,4-NADH formed before and after the enzymatic reaction can be calculated by the following formula.

[0059] C 1,4-NADH =[A0-(A t -A e )] / ε 1,4-NADH

[0060] Where A0 is the initial absorbance before the enzyme catalyzed reaction, A t A is the final absorbance after the enzyme catalyzed reaction e is the absorbance of the enzyme solution system, ε 1,4-NADH This is the absorbance coefficient obtained by measuring the 1,4-NADH UV standard curve.

[0061] The technical scheme of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the embodiments described herein are only some embodiments of the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments implemented by ordinary technicians in this field without making creative improvements belong to the protection scope of the present invention.

[0062] Embodiment 1:

[0063] S1a: Cut the copper foam (CF) into 1x2 cm size, immerse it in 1M HCl solution, and clean it by ultrasonic for 10 min to remove the surface oxide layer. Then take out the copper foam, rinse it with water and acetone, blow dry it, and place it in argon atmosphere for later use.

[0064] S2a: First, prepare the CuO nanowire precursor as follows: first, dissolve 3.0M KOH in deionized water as the electrolyte, and put the pretreated CF as the anode and the platinum wire electrode as the cathode into a two-electrode electrolytic cell, and perform in-situ oxidation by means of chronopotentiometry, with a potential range of 0.00-2.00V and a current density of 10mAcm -2 , the reaction time is 20min, and blue Cu(OH)2 nanowires are formed on the surface of CF after the reaction. After continuous rinsing with water and ethanol, it is placed in a vacuum drying oven at 65℃ overnight. The Cu(OH)2 nanowires obtained after drying are then placed in a tube furnace and calcined in an air atmosphere at 180℃ for 2h. After cooling, black CuO nanowires are obtained. The CuO nanowires are in situ reduced using the chronoamperometry method. The cathode is CuO nanowires, the anode is platinum wire, the electrolyte is 0.1M PBS solution with pH=7, and the potential is -1.1Vvs.Ag / AgCl. After 15min of power on, it is observed that the electrode slowly turns red, and Cu nanowires (Cu NWs / CF) are obtained.

[0065] S3a: First, dissolve 0.1M copper sulfate pentahydrate, stir continuously in 50mL distilled water with a magnetic stirrer for 10min, add 50mmol of thioacetamide, and stir evenly. Finally, add 35mmol of acetic acid dropwise and stir for 30min. Transfer the final reaction solution to a chemical bath deposition (CBD) container, place the prepared Cu nanowires vertically in the container, heat at 65°C for 2h, cool the container naturally, then wash the electrode with ethanol and distilled water in turn, and finally dry it in a vacuum drying oven at 65°C for 24h.

[0066] S4a: NADH directed regeneration is carried out in a three-electrode system, where Cu x S NWs / CF was used as the working electrode, Pt sheet as the counter electrode, Ag / AgCl electrode as the reference electrode, the on-state potential was -1.2 V vs. Ag / AgCl, the electrolyte solution was 0.1 M phosphate buffer (PBS) with pH = 7, a sealed H-type electrolytic cell was used, the reaction temperature was room temperature (25 ° C), the electrolysis process was protected under Ar atmosphere, and the substrate was 1 mM reduced nicotinamide adenine dinucleotide disodium salt (NAD + ).

[0067] Example 2

[0068] Electrocatalysis of NAD was carried out according to the method of Example 1+ , the difference is that the electrocatalytic potential in S4a is -1.1 V vs. Ag / AgCl.

[0069] Example 3

[0070] Electrocatalysis of NAD was carried out according to the method of Example 1 + , the difference is that the electrocatalytic potential in S4a is -1.25 V vs. Ag / AgCl.

[0071] Example 4

[0072] Electrocatalysis of NAD was carried out according to the method of Example 1 + , the difference is that the electrocatalytic pH in S4a is 6.8.

[0073] Example 5

[0074] Electrocatalysis of NAD was carried out according to the method of Example 1 + , the difference is that the electrocatalytic pH in S4a is 7.2.

[0075] Example 6

[0076] S1b: Cut the copper foam (CF) into 1x2 cm size, immerse it in 1M HCl solution, and clean it by ultrasonic for 10 min to remove the surface oxide layer. Then take out the copper foam, rinse it with water and acetone, blow dry it, and place it in argon atmosphere for later use.

[0077] S2b: First, the CuO nanowire precursor was prepared as follows: 3.0 M KOH was dissolved in deionized water as the electrolyte, and the pretreated CF was used as the anode and the platinum wire electrode was used as the cathode in a two-electrode electrolytic cell. In situ oxidation was performed by chronopotentiometry with a potential range of 0.00-2.00 V and a current density of 10 mA cm -2 , the reaction time is 20min. After the reaction, blue Cu(OH)2 nanowires are formed on the surface of CF. After continuous washing with water and ethanol, it is placed in a vacuum drying oven at 70℃ overnight. Subsequently, the Cu(OH)2 nanowires obtained after drying are placed in a tubular furnace and calcined at 180℃ in air atmosphere for 2h. After cooling, black CuO nanowires are obtained.

[0078] S3b: First, dissolve 0.1M copper sulfate pentahydrate, stir continuously in 50mL distilled water with a magnetic stirrer for 10min, add 50mmol of thioacetamide, and stir evenly. Finally, add 35mmol of acetic acid dropwise and stir for 30min. Transfer the final reaction solution to a chemical bath deposition (CBD) container, place the prepared Cu nanowires vertically in the container, heat at 65°C for 2h, cool the container naturally, then wash the electrode with ethanol and distilled water in turn, and finally dry it in a vacuum drying oven at 65°C for 24h.

[0079] S4b: NADH directed regeneration is carried out in a three-electrode system, where Cu x S NWs / CF was used as the working electrode, Pt sheet as the counter electrode, Ag / AgCl electrode as the reference electrode, and the on-state potential was -1.2 V vs. Ag / AgCl. The electrolyte solution was 0.1 M phosphate buffer (PBS) with pH = 7. A sealed H-type electrolytic cell was used. The reaction temperature was room temperature (25 °C). The electrolysis process was protected under Ar atmosphere throughout. The substrate was 1 mM reduced nicotinamide adenine dinucleotide disodium salt (NAD + ).

[0080] Example 7

[0081] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic potential in S4b is -1.1 V vs. Ag / AgCl.

[0082] Example 8

[0083] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic potential in S4b is -1.25 V vs. Ag / AgCl.

[0084] Example 9

[0085] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic pH in S4b is 6.8.

[0086] Example 10

[0087] Electrocatalysis of NAD was carried out according to the method of Example 6 + , except that the electrocatalytic pH in S4b is 7.2.

[0088] Comparative Example 1

[0089] Electrocatalysis of NAD according to the method of Example 1 + , the difference is that Cu x S is copper sulfide generated by high-temperature heat treatment of copper foam (CF) as a substrate with sulfur powder in a tube furnace.

[0090] Comparative Example 2

[0091] Electrocatalysis of NAD according to the method of Example 1 + , the difference is that the electrocatalytic potential in S4a is -1.0 Vvs.Ag / AgCl.

[0092] Comparative Example 3

[0093] Electrocatalysis of NAD according to the method of Example 1+ , the difference is that the electrocatalytic potential in S4a is -1.4 Vvs.Ag / AgCl.

[0094] Comparative Example 4

[0095] Electrocatalysis of NAD according to the method of Example 1 + , the difference is that the electrocatalytic pH in S4a is 6.5.

[0096] Comparative Example 5

[0097] Electrocatalysis of NAD according to the method of Example 1 + , the difference is that the electrocatalytic pH in S4a is 7.5.

[0098] Comparative Example 6

[0099] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic potential in S4b is -1.0 Vvs.Ag / AgCl.

[0100] Comparative Example 7

[0101] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic potential in S4b is -1.3 Vvs.Ag / AgCl.

[0102] Comparative Example 8

[0103] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic pH in S4b is 6.5.

[0104] Comparative Example 9

[0105] Electrocatalysis of NAD was carried out according to the method of Example 6 + , the difference is that the electrocatalytic pH in S4b is 7.5.

[0106] The selectivity of electrocatalytic hydrogenation of 1,4-NADH in Examples 1-10 and Comparative Examples 1-9 is shown in Table 1.

[0107] Table 1

[0108]

[0109]

[0110] It can be seen from the examples and comparative examples that the preparation method of the present invention can be used to electrocatalyze the reaction of NAD with high selectivity. + 1,4-NADH is produced as a substrate.

[0111] The electrocatalytic potential of Comparative Examples 3 and 7 was -1.4 V vs. Ag / AgCl. The reason for the poor selectivity was that the excessively high potential caused H ad The energy is too high and the hydrogenation sites become disordered.

[0112] The method provided in the present application uses Cu nanowires or CuO nanowires as precursors and performs in-situ growth thereon to prepare copper sulfide nanowires (Cu x The highest hydrogenation selectivity at the 1,4 position of the S NWs / CF) catalyst was 90.3%.

[0113] Figure 1 The Cu prepared in Example 1 x Scanning electron microscopy (SEM) images of S NWs / CF show that Cu x SNWs / CF has the morphology of nanowires, and the overall morphology is the same as that of Cu NWs / CF precursor. The length of the nanowires is about 100-800nm, and the diameter is 15-40nm. Some nanospheres appear on the nanowires, confirming that the morphology of copper sulfide nanowires is correctly synthesized.

[0114] Figure 2 This is a scanning electron microscope (SEM) image of the Cu nanowires prepared in Example 1. It can be seen that the Cu nanowires grow uniformly on the CF skeleton. The length of the nanowires is about 100-800nm ​​and the diameter is 15-40nm, which confirms that the precursor morphology is synthesized correctly.

[0115] Figure 3 The foam copper, Cu nanowires, and Cu prepared in Example 1 x The comparison of the selectivity of Cu NWs / CF catalyst for NADH hydrogenation shows that the selectivity of 1,4-NADH regeneration is higher than that of unmodified copper foam, indicating that this morphology has certain advantages for selective hydrogenation. x The hydrogenation selectivity of the S NWs / CF electrode has been significantly improved, indicating that the introduction of sulfur doping has a significant promoting effect on improving its hydrogenation at the 1,4 positions.

[0116] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for electrocatalytic NADH regeneration, characterized in that: The following steps are involved: S1a: The copper foam was immersed in HCl solution, sonicated, rinsed with water and acetone, dried and placed in an argon atmosphere for later use; S2a: Using the copper foam treated with S1 as the anode, platinum wire as the cathode, and KOH solution as the electrolyte, the copper foam was in situ oxidized by chronopotentiometry, washed with water and ethanol, dried in vacuum, and calcined in a tube furnace to obtain CuO nanowires. Using the CuO nanowires as the cathode and the platinum wire as the anode, the CuO nanowires were in situ reduced by chronoamperometry to obtain Cu nanowires. S3a: Add thioacetamide to the copper sulfate solution, stir it for the first time, add acetic acid, stir it for the second time, obtain a reaction solution, add the Cu nanowires and the reaction solution into a chemical bath deposition container, heat it, wash it, and dry it to obtain Cu x S nanowire, wherein x is 1 to 2; S4a: Cu x S nanowires were used as working electrodes, Pt sheets were used as counter electrodes, and Ag / AgCl electrodes were used as reference electrodes. Electrocatalysis of NAD + Regenerate 1,4-NADH; or, S1b: immerse the copper foam in HCl solution, sonicate, rinse with water and acetone, dry and place in argon atmosphere for later use; S2b: The copper foam treated with S1 was used as the anode, the platinum wire as the cathode, and the KOH solution as the electrolyte. The copper foam was in situ oxidized by chronopotentiometry, washed with water and ethanol, dried in vacuum, and calcined in a tube furnace to obtain CuO nanowires. S3b: Add thioacetamide to the copper sulfate solution, stir it for the first time, add acetic acid, stir it for the second time, obtain a reaction solution, add the CuO nanowires and the reaction solution into a chemical bath deposition container, heat it, wash it, and dry it to obtain Cu x S nanowire, wherein x is 1 to 2; S4b: Cu x S nanowires were used as working electrodes, Pt sheets were used as counter electrodes, and Ag / AgCl electrodes were used as reference electrodes. Electrocatalysis of NAD + Regenerate 1,4-NADH; Wherein, in S4a or S4b, the electrocatalytic potential is -1.1 to -1.25 V vs. Ag / AgCl.

2. The method according to claim 1, characterized in that In S1a or S1b, the concentration of the HCl solution is 0.1-1 M, and the ultrasonic time is 5-10 min.

3. The method according to claim 1, characterized in that In S2a or S2b, the concentration of the KOH solution is 2-5M.

4. The method according to claim 1, characterized in that In S2a or S2b, the in-situ oxidation conditions include: the potential range of the in-situ oxidation is 0-2V, the current of the in-situ oxidation is 5-20mAcm -2 The reaction time of in-situ oxidation is 15-25min.

5. The method according to claim 1, characterized in that In S2a or S2b, the vacuum drying conditions include: a drying temperature of 60-80°C; In S2a or S2b, the calcination conditions include: in an air atmosphere, a calcination temperature of 160-200° C., and a calcination time of 2-3 h; In S2a, the conditions for the in-situ reduction include: the electrolyte is a PBS solution, the electrolyte pH is 6-8, the electrolyte concentration is 0.05-0.2M, the potential is -1.1 to -1.3Vvs.Ag / AgCl, and the power-on time is 10-20min.

6. The method according to claim 1, characterized in that In S3a or S3b, the molar ratio of copper sulfate to thioacetamide is 1:0.4-0.6, and the molar ratio of copper sulfate to acetic acid is 1:0.2-0.

5.

7. The method according to claim 1, characterized in that In S3a or S3b, the first stirring time is 5-10 min, and the second stirring time is 5-10 min; In S3a or S3b, the heating conditions include: heating time of 1.5-2.5h, heating temperature of 60-80°C; In S3a or S3b, the vacuum drying conditions include: the drying temperature is 60-70°C.

8. The method according to claim 1, characterized in that In S4a or S4b, the electrocatalytic conditions include: the substrate is reduced nicotinamide adenine dinucleotide disodium salt NAD + , Nicotinamide adenine dinucleotide disodium salt (NAD) + The concentration is 0.5-2 mM, the electrocatalytic pH is 6.8-7.2, and the electrocatalytic time is 60-120 min.

9. Cu prepared by the method according to any one of claims 1 to 9 x S nanowires.

10. The method according to any one of claims 1 to 8 or the Cu according to claim 9 x Application of S nanowires in electrocatalysis.

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