A biofuel cell based on nickel-iron Prussian blue, its preparation method and application

Abstract

This invention discloses a biofuel cell based on nickel-iron Prussian blue, its preparation method, and its application, belonging to the field of fuel cell technology. First, nickel-iron Prussian blue with excellent laccase activity is synthesized as an electrocatalyst. A glassy carbon electrode modified with this electrocatalyst is used as the anode and cathode to construct a non-enzymatic biofuel cell. Using catechol or hydroquinone as fuel, it exhibits good power output and operational stability. The biofuel cell based on nickel-iron Prussian blue not only significantly improves the performance and stability of biofuel cells but also has advantages such as low cost and simple operation. The constructed enzyme-free biofuel cell enables rapid detection of catechol or hydroquinone in simulated wastewater.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically relating to a biofuel cell based on nickel-iron Prussian blue, its preparation method, and its application. Background Technology

[0002] Biofuel cells are a special type of fuel cell in which biocatalysts such as enzymes and microorganisms act as catalysts, and biomass serves as fuel. Compared to traditional fuel cells, biofuel cells are active under mild conditions (such as room temperature and neutral pH), and are therefore considered a potential green energy technology.

[0003] Enzyme-based biofuel cells are electrochemical devices that use enzymes, biocatalysts, to convert the chemical energy of various fuels into electrical energy. They possess advantages such as environmental friendliness, good biocompatibility, and mild operating conditions, making them promising for broad applications. Therefore, enzyme-based biofuel cells are considered a more reliable portable energy source. However, most biofuel cell construction paradigms (whether enzyme-based or enzyme-free) are based on a "heteroelectrode" strategy, where the anode and cathode use different types of catalysts to optimize fuel oxidation and oxidant reduction reactions, respectively. However, this strategy inevitably introduces compatibility issues between different material interfaces, potential mutual interference, and complex fabrication processes.

[0004] Laccase is a copper-containing polyphenol oxidase that can rapidly catalyze the oxidation of phenolic substances under mild reaction conditions without the generation of other pollutants. While enzyme-based biofuel cells exhibit high power generation efficiency with the assistance of natural enzymes, the fragility of natural enzymes under varying environmental conditions severely hinders their practical application. In contrast, nanozymes have attracted attention due to their inherent advantages, such as high stability under harsh conditions, ease of large-scale production, low synthesis cost, and tunable catalytic activity. Nickel-iron Prussian blue (NiFe PBA) has been found to efficiently catalyze the oxidation of phenolic fuels such as catechol on the anode side; on the cathode side, it exhibits excellent four-electron pathway oxygen reduction reaction catalysis. This "two birds with one stone" characteristic provides new insights for designing battery structures. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a biofuel cell based on nickel-iron Prussian blue, its preparation method, and its application. Using NiFePBA, which exhibits excellent laccase activity, as an electrocatalyst, and glassy carbon electrodes modified with this electrocatalyst as the anode and cathode, a non-enzymatic biofuel cell is constructed. Using catechol or hydroquinone as fuel, it exhibits good power output and operational stability. Based on the constructed enzyme-free biofuel cell, rapid detection of catechol or hydroquinone in simulated wastewater can be achieved.

[0006] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a biofuel cell based on nickel-iron Prussian blue, wherein the anode and cathode of the biofuel cell are both glassy carbon electrodes loaded with nickel-iron Prussian blue nanoparticles.

[0007] Furthermore, the biofuel cell constructed based on nickel-iron Prussian blue is a dual-chamber H-type biofuel cell, with the anode chamber and cathode chamber separated by a proton exchange membrane. The anode electrolyte is a PBS buffer solution of catechol or hydroquinone, and the cathode electrolyte is a PBS buffer solution.

[0008] Furthermore, the proton exchange membrane is a DuPont Nafion 117 membrane.

[0009] Furthermore, the concentration of the catechol or hydroquinone PBS buffer is 0.5 μM to 20 mM, and the pH value is 6 to 7; the pH value of the cathode electrolyte is 7 to 8.

[0010] Furthermore, the preparation method of the nickel-iron Prussian blue nanoparticles is as follows: (1) Mix Ni(CH3COO)2 and C6H5Na3O7 in water to obtain solution A; (2) Add K3Fe(CN)6 solution to solution A, mix and age at room temperature to obtain nickel-iron Prussian blue nanoparticles.

[0011] Furthermore, the molar ratio of Ni(CH3COO)2, C6H5Na3O7 and K3Fe(CN)6 is 1:1.2~1.3:0.6~0.8; the aging time at room temperature is 22-26 hours.

[0012] Furthermore, in step (1), the concentration of Ni(CH3COO)2 in solution A is 29~32mM; in step (2), the concentration of K3Fe(CN)6 solution is 10~15mM.

[0013] In a second aspect, the present invention provides a method for preparing the aforementioned biofuel cell based on nickel-iron Prussian blue, comprising the following steps: (1) The polished glassy carbon electrode was sonicated in water and anhydrous ethanol for 5-7 s respectively. 5-10 μL of nickel-iron Prussian blue nanoparticle solution with a concentration of 1-2 mg / mL was dropped onto the glassy carbon electrode. After drying, 1-3 μL of 0.02-0.05% Nafion was added to obtain the nickel-iron Prussian blue modified electrode. (2) Nickel-iron Prussian blue modified electrodes are used as the anode and cathode of a biofuel cell, and the anode electrolyte and cathode electrolyte are used in a biofuel cell.

[0014] Furthermore, the inner diameter of the glassy carbon electrode in step (1) is 2.8~3 mm.

[0015] In a third aspect, the present invention provides the application of the aforementioned nickel-iron Prussian blue-based biofuel cell in the detection of catechol or / or hydroquinone.

[0016] This invention constructs a dual-chamber biofuel cell using catechol / hydroquinone as fuel and nickel-iron Prussian blue nanoparticle-modified electrodes as the anode / cathode. The anode modified with nickel-iron Prussian blue nanoparticles exhibits excellent electrocatalytic activity against catechol / hydroquinone, enabling oxidation at relatively low potentials, thus meeting the requirement for low anode potential. The nickel-iron Prussian blue nanoparticles, due to their laccase-like activity, can provide a suitable oxygen reduction potential. The reaction principle diagram for the detection of catechol or hydroquinone in the biofuel cell based on nickel-iron Prussian blue is shown below. Figure 1 As shown, this is the first time that a non-enzymatic biofuel cell has been constructed using a nickel-iron Prussian blue modified electrode as the anode / cathode, and a method for detecting catechol or hydroquinone based on the biofuel cell has been established.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) The biofuel cell constructed in this invention based on nickel-iron Prussian blue utilizes NiFe PBA bioanodine for electrocatalytic oxidation of catechol / hydroquinone to generate electrons, which are then transferred to the cathode for NiFe PBA catalytic oxygen reduction, accompanied by current generation; in a 5 mM catechol solution, the output potential of this cell is 165 mV and the maximum power density is 8.02 μW. cm 2 In a 5 mM hydroquinone solution, the fuel cell exhibits an output potential of 270 mV and a maximum power density of 13.3 μW. cm 2 It also has excellent stability.

[0018] (2) The NiFe PBA used in this invention was developed to mimic the activity of natural laccase. The NiFe PBA nanomaterial-modified anode exhibits good electrocatalytic performance for catechol and hydroquinone, and the NiFe PBA nanomaterial-modified cathode exhibits good oxygen reduction performance, low overpotential, stable performance, and a simple modification process. The constructed biofuel cell can not only significantly improve the performance and stability of the biofuel cell, but also has the advantages of low cost and simple operation.

[0019] (3) This invention utilizes simple stirring to synthesize nanomaterials. The synthesized materials were then used to investigate the laccase activity. The Michaelis constant was 0.086 mM, and the maximum reaction rate was [not specified]. V max 0.280 μM s 1 It is far superior to natural laccase ( V max =0.025 μM s 1 The excellent enzyme-mimicking activity further enhances the battery's power generation performance. Attached Figure Description

[0020] Figure 1 A schematic diagram illustrating the reaction principle for detecting catechol or hydroquinone in a biofuel cell constructed based on nickel-iron Prussian blue. Figure 2 The images show the scanning electron microscope (SEM) image and elemental mapping image of NiFePBA. A is the SEM image, and B is the elemental mapping image. Figure 3 X-ray diffraction pattern of NiFePBA; Figure 4 The X-ray photoelectron spectra of NiFe PBA are shown below. A is the full XPS spectrum, B is the Ni 2p XPS spectrum, and C is the Fe 2p XPS spectrum. Figure 5 The graph shows the activity results of NiFe PBA laccase assay. Figure 6 The double reciprocal plot is shown for the enzyme activity dynamics analysis of NiFe PBA. Figure 7 Cyclic voltammetry curves for nickel-iron Prussian blue anodes; Figure 8 Cyclic voltammetry curves for nickel-iron Prussian blue cathodes; Figure 9 The graphs show the polarization curves and power density curves of the biofuel cell based on nickel-iron Prussian blue prepared in Example 3. Line a is the polarization curve and line b is the power density curve. Figure 10 Power density curves of biofuel cells based on nickel-iron Prussian blue with different catechol concentrations; Figure 11 The figure shows the stability test results of the biofuel cell based on nickel-iron Prussian blue prepared in Example 3; Figure 12 The graphs show the polarization curves and power density curves of the biofuel cell based on nickel-iron Prussian blue prepared in Example 4. Line a is the polarization curve and line b is the power density curve. Figure 13 Power density curves of biofuel cells based on nickel-iron-Prussian blue for different hydroquinone concentrations; Figure 14 Power density curves and linear relationship curves between substrate concentration and maximum power density of biofuel cells based on nickel-iron-Prussian blue constructed with different hydroquinone / catechol concentrations are shown in Figure A. Power density curves of biofuel cells based on nickel-iron-Prussian blue constructed with different hydroquinone concentrations are shown in Figure B. Power density curves of biofuel cells based on nickel-iron-Prussian blue constructed with different catechol concentrations are shown in Figure C. Linear relationship curves between maximum power density and substrate concentration are shown in Figure C. Figure 15 The specific detection results of biofuel cells based on nickel-iron Prussian blue constructed for different anolytes are shown in the figure. Detailed Implementation

[0021] The present invention is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods not specifically described in the following examples are generally performed under conventional conditions or as recommended by the manufacturer.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of skill in the art. All reagents and materials used in this invention are readily available through conventional means, and unless otherwise specified, they shall be used in accordance with conventional methods in the art or as per the product instructions.

[0023] Example 1 Preparation of nickel-iron Prussian blue nanoparticles (NiFe PBA): (1) Ni(CH3COO)2 and C6H5Na3O7 solution are dissolved in water to obtain solution A. The concentration of Ni(CH3COO)2 in solution A is 30 mM and the concentration of C6H5Na3O7 is 37 mM. (2) K3Fe(CN)6 dissolves in water to obtain solution B, and the concentration of K3Fe(CN)6 in solution B is 13.3 mM; (3) Add 60 mL of solution B to 40 mL of solution A, stir continuously for 1 min, age at room temperature for 24 hours, centrifuge the reaction solution, wash with deionized water and ethanol alternately 3 times, and vacuum dry at 60 °C overnight to obtain nickel-iron Prussian blue nanoparticles (NiFe PBA).

[0024] Scanning electron microscope image of NiFePBA as follows Figure 2As shown in Figure A, NiFePBA exists in a cubic shape with a size of approximately 90-110 nm; the elemental mapping image of NiFePBA is as follows. Figure 2 As shown in Figure B, the image shows that C, N, O, Ni, and Fe elements are uniformly distributed in NiFe PBA.

[0025] The X-ray diffraction pattern of NiFePBA is as follows: Figure 3 As shown, by Figure 3 It can be seen that in 2 θ Strong and sharp diffraction peaks were observed at 14.0°, 17.3°, 24.6°, 28.9°, 30.2°, 35.1°, 39.4°, 43.3°, 46.1°, 50.4°, 53.7°, 56.9°, 59.2°, 62.9°, 65.8°, and 68.6°, corresponding to the lattice planes (111), (200), (220), (311), (222), (400), (420), (422), (511), (440), (600), (620), (533), (444), (640), and (642), respectively, indicating that the crystal has high crystallinity and large grain size. The X-ray photoelectron spectrum of NiFePBA is as follows: Figure 4 As shown, A is the XPS full spectrum, B is the Ni 2p XPS spectrum, and C is the Fe 2p XPS spectrum. The elemental composition and valence states of NiFePBA were analyzed using XPS. Electronic energy peaks for C, O, N, Fe, and Ni were observed in the XPS full spectrum. In the Ni 2p XPS spectrum, the two peaks at 854.67 eV and 856.71 eV are attributed to Ni. 2+ and Ni 3+ Ni 2p 3 / 2 The two peaks at 871.86 eV and 874.27 eV are attributed to Ni, respectively. 2+ and Ni 3+ Ni 2p 1 / 2 The binding energy indicates that the material contains nickel in two valence states simultaneously (Ni). 2+ and Ni 3+ In the Fe2p XPS spectrum, the two peaks at 709.73 eV and 711.85 eV are attributed to Fe. 2+ and Fe 3+ Fe 2p 3 / 2 The binding energy, with peaks at 722.91 eV and 725.2 eV, is attributed to Fe. 2+ and Fe 3+ Fe 2p 1 / 2 The binding energies correspond to [Fe(CN)6], respectively.4 and [Fe(CN)6] 3 .

[0026] The above characterization results demonstrate that nickel-iron Prussian blue nanoparticles (NiFe PBA) were successfully prepared.

[0027] Example 2 Preparation of electrodes for biofuel cells based on nickel-iron Prussian blue After the NiFe PBA prepared in Example 1 was ground into powder in a mortar, 2 mg was weighed out, dispersed in 1 mL of ultrapure water, and sonicated for 30 min to prepare a uniformly dispersed nanomaterial suspension. Because NiFe PBA is small in size and difficult to fix on the electrode surface, a certain amount of chitosan is added during the modification process to enable NiFe PBA to be successfully fixed on the electrode surface. 1 mg of chitosan is weighed and dispersed in 1 mL of 1% acetic acid. The mixture is sonicated for 30 min to prepare a completely dissolved chitosan solution. 180 μL of NiFe PBA nanomaterial suspension and 20 μL of completely dissolved chitosan solution are mixed and sonicated for 30 min to obtain a mixture containing NiFe PBA nanomaterial. A glassy carbon electrode (GCE, inner diameter 3 mm) was polished with 0.3 μm alumina powder, and then sonicated in water and anhydrous ethanol for 6 s to remove residual alumina particles. Subsequently, 8 μL of a mixture containing NiFe PBA nanomaterials was drop-coated onto the cleaned glassy carbon electrode and dried under an infrared lamp. After the electrode was dried, 5 μL of 0.05% Nafion 117 solution was added to prevent material detachment, thus preparing a nickel-iron Prussian blue modified electrode.

[0028] Example 3 Preparation of biofuel cells based on nickel-iron Prussian blue In this embodiment, the nickel-iron Prussian blue biofuel cell is a dual-chamber H-type biofuel cell, comprising an anode chamber, a cathode chamber, and a proton exchange membrane. The proton exchange membrane uses Nafion 117 (183 μm) to divide the cell into an anode chamber and a cathode chamber, each with a volume of 10 mL. Using the nickel-iron Prussian blue modified electrode prepared in Example 2 as the anode, and 5 mM catechol in PBS buffer (pH 6) as the anode electrolyte, and using the nickel-iron Prussian blue modified electrode prepared in Example 2 as the cathode, and PBS buffer (pH 7) as the cathode electrolyte, the above-mentioned dual-chamber H-type biofuel cell was constructed, which is a biofuel cell based on nickel-iron Prussian blue.

[0029] Example 4 Preparation of biofuel cells based on nickel-iron Prussian blue (unlike Example 3, in Example 4 the anolyte is 5 mM hydroquinone in PBS buffer (pH 6)).

[0030] In this embodiment, the nickel-iron Prussian blue biofuel cell is a dual-chamber H-type biofuel cell, comprising an anode, an anode chamber, a cathode, a cathode chamber, and a proton exchange membrane. The proton exchange membrane uses Nafion 117 to divide the cell into an anode chamber and a cathode chamber, each with a volume of 10 mL. Using the nickel-iron Prussian blue modified electrode prepared in Example 2 as the anode, and 5 mM hydroquinone in PBS buffer (pH 6) as the anode electrolyte, and using the nickel-iron Prussian blue modified electrode prepared in Example 2 as the cathode, and PBS buffer (pH 7) as the cathode electrolyte, the above-mentioned dual-chamber H-type biofuel cell was constructed, which is a biofuel cell based on nickel-iron Prussian blue.

[0031] Experimental Example 1 The laccase-mimicking activity assay of NiFe PBA showed that, under air-saturated conditions, 2,4-DP, as a substrate for laccase, was oxidized by laccase to 2,4-dichlorobenzoquinone. This benzoquinone further reacted with 4-AP to generate quinone imine (QI), which exhibited a strong absorption peak at 510 nm. The molar extinction coefficient of QI was ε = 12600 cm⁻¹. L mol -1 The reaction formulas for NiFePBA and 2,4-DP, and NiFePBA and 2,4-DP, 4-AP are shown below: The method for testing the laccase mimicry activity of NiFe PBA is as follows: 2,4-Dichlorophenol (2,4-DP) (10 mM, 30 μL) and 4-aminoantipyrine (4-AP) (10 mM, 30 μL), along with NiFe PBA synthesized in Example 1 (1 mg / mL, 30 μL), were sonicated into phosphate buffer (pH 7, 210 μL) and incubated at 25 °C for 10 min. A control group without NiFe PBA was used. 200 μL of the solution was transferred to a 96-well plate, and its absorbance at 510 nm was measured (A). 510nm ).

[0032] The laccase activity test results of NiFe PBA prepared in Example 1 are shown in the figure below. Figure 5 As shown, by Figure 5It can be seen that, compared with the control groups 2,4-DP+NiFe PBA (a), 4-AP+NiFe PBA (b), 2,4-DP (d), 4-AP (e), NiFe PBA (f), and 2,4-DP+4-AP (g), only the 2,4-DP+4-AP+NiFe PBA mixture (curve c) showed a significant absorption peak at 510 nm, indicating that NiFe PBA possesses laccase-mimicking activity. The double reciprocal curves for the enzyme activity analysis of NiFe PBA are shown below. Figure 6 As shown, by Figure 6 It can be seen that the Michaelis constant of NiFePBA is 0.086 mM, and the maximum reaction rate is 0.280 μM s. 1 .

[0033] Experimental Example 2 Electrocatalytic oxidation performance test of nickel-iron Prussian blue anode The electrocatalytic oxidation performance of the nickel-iron Prussian blue anode was tested using a standard three-electrode system. The nickel-iron Prussian blue anode was used as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum sheet as the counter electrode. The electrolyte was phosphate-buffered saline (PBS, pH 6.0) containing 5 mM catechol. Electrochemical tests were conducted at room temperature in an air-saturated environment, and the electrocatalytic oxidation activity of the nickel-iron Prussian blue anode was tested using cyclic voltammetry (CV). The cyclic voltammetric (CV) curves of the nickel-iron Prussian blue anode are shown below. Figure 7 As shown, lines a and b represent the CV curves of a bare glassy carbon electrode in 1 mM and 5 mM catechol, respectively, while lines c and d represent the CV curves of a nickel-iron Prussian blue anode in 1 mM and 5 mM catechol, respectively. In catechol solutions of the same concentration, the oxidation peak current of the nickel-iron Prussian blue anode is significantly higher than that of the bare glassy carbon electrode, and the oxidation peak current of 5 mM catechol (line d) is significantly higher than that of 1 mM catechol (line c). This indicates that the nickel-iron Prussian blue anode effectively catalyzes the oxidation of catechol.

[0034] Experimental Example 3 Electrocatalytic oxygen reduction activity test of nickel-iron Prussian blue cathode The electrocatalytic oxygen reduction activity of the nickel-iron Prussian blue cathode was detected using a standard three-electrode system. The nickel-iron Prussian blue cathode was used as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum sheet as the counter electrode. The electrolyte was phosphate-buffered saline (PBS, pH 7), and electrochemical tests were performed at room temperature in an air-saturated environment. First, linear sweep voltammetry (LSV) was used to analyze the nickel-iron Prussian blue cathode. Tests were conducted under argon-saturated and air-saturated environments to investigate the onset potential of NiFe PBA-catalyzed oxygen reduction. The LSV curves of the nickel-iron Prussian blue cathode are shown below. Figure 8As shown, curve a is in an argon-saturated environment, and curve b is in an air-saturated environment. Figure 8 The results showed that the oxygen reduction onset potential of the nickel-iron Prussian blue cathode was 527 mV, indicating that the nickel-iron Prussian blue cathode has a relatively low overpotential for catalytic oxygen reduction and can be used as a cathode for biofuel cells.

[0035] Test Example 4 Performance testing of biofuel cells based on nickel-iron Prussian blue prepared in Example 3 (1) Using linear scanning voltammetry at a scan rate of 10 mV / s, the polarization curve and power density curve of the biofuel cell based on nickel-iron Prussian blue prepared in Example 3 are shown below. Figure 9 As shown, line a is the polarization curve, and line b is the power density curve; from Figure 9 It can be seen that the output potential of the biofuel cell based on nickel-iron Prussian blue prepared in Example 3 is 165mV, and the maximum power density is 8.02 μWcm³. 2 .

[0036] By varying the concentration of catechol in the anolyte of Example 3 (PBS buffer containing 1, 2, 3, 5, 10, and 20 mM catechol, respectively), biofuel cells based on nickel-iron Prussian blue with different catechol concentrations were constructed, and their power density curves were measured. The results are as follows: Figure 10 As shown, the maximum power output density and open-circuit voltage of the biofuel cell based on nickel-iron Prussian blue increase with the increase of catechol concentration.

[0037] (2) The stability of the biofuel cell based on nickel-iron Prussian blue prepared in Example 3 was tested, and the results are as follows: Figure 11 As shown, by Figure 11 It can be seen that the biofuel cell based on nickel-iron Prussian blue prepared in Example 3 can still maintain 98% of its output voltage after running continuously for 6 hours.

[0038] The above results indicate that the biofuel cell constructed using NiFe PBA as both anode and cathode catalysts in this invention exhibits good potential output and power output.

[0039] Experimental Example 5 Performance testing of biofuel cells based on nickel-iron Prussian blue prepared in Example 4 (1) Using linear scanning voltammetry at a scan rate of 10 mV / s, the polarization curve and power density curve of the biofuel cell based on nickel-iron Prussian blue prepared in Example 4 are shown below. Figure 12 As shown, line a is the polarization curve, and line b is the power density curve; from Figure 12It can be seen that the output potential of the biofuel cell based on nickel-iron Prussian blue prepared in Example 4 is 270 mV, and the maximum power density is 13.3 μW / cm³. 2 .

[0040] By varying the hydroquinone concentration in the anolyte of Example 4 (PBS buffer containing 1, 2, 3, 5, 10, and 20 mM hydroquinone, respectively), biofuel cells based on nickel-iron Prussian blue with different hydroquinone concentrations were constructed, and their power density curves were measured. The results are as follows: Figure 13 As shown, the maximum power output density and open-circuit voltage of the biofuel cell based on nickel-iron Prussian blue increase with the increase of catechol concentration.

[0041] Experimental Example 6 Application of Nickel-Iron Prussian Blue-Based Biofuel Cells in Sensor Fabrication By varying the hydroquinone concentration (0.5 μM-5 mM) in Example 4, biofuel cells based on nickel-iron Prussian blue with different hydroquinone concentrations were constructed, and their power density curves were measured. The results are as follows: Figure 14 As shown in Figure A; by changing the concentration of catechol in Example 3 (5 μM-5 mM), biofuel cells based on nickel-iron Prussian blue with different catechol concentrations were constructed, and their power density curves were measured. The results are shown in Figure A. Figure 14 As shown in B; with the concentrations of catechol and hydroquinone on the x-axis and the maximum power density on the y-axis, the results are as follows. Figure 14 As shown in Figure C, the maximum power density increases with increasing concentrations of hydroquinone (HQ) and catechol (CC). The maximum power density value is related to the concentration of hydroquinone (C). HQ The equations show three linear relationships: 0.5-20 μM (linear regression equation). P max =0.0272C HQ +0.571, R 2 =0.995), 20μM-1mM (linear regression equation) P max =0.00480C HQ +0.993, R 2 =0.992), 1mM -5mM (linear regression equation) P max =0.0021 C HQ +3.776, R 2 =0.977). Maximum power density value and catechol (C CC The concentration of ) showed three linear relationships: 5μM-20μM (linear regression equation) P max=0.0142C CC +0.466,R 2 =0.995), 20μM-0.5mM (linear regression equation) P max = 0.00572 C CC +0.637, R 2 =0.992), 1mM -5mM (linear regression equation) P max = 0.00121 C CC +2.49, R 2 =0.989). The calculated limit of detection (LOD) for hydroquinone was 0.23 μM, and the limit of detection (LOD) for catechol was 0.45 μM.

[0042] To investigate the specificity of nickel-iron Prussian blue-constructed biofuel cells as sensors for detecting catechol and / or hydroquinone, several phenolic contaminants with structures similar to catechol and hydroquinone, such as bisphenol A (BPA), phenol (PhOH), salicylic acid (SA), p-nitrophenol (PNP), and resorcinol (R), were selected as components of the anolyte at a concentration of 10 mM. CC and HQ, at concentrations of 5 mM, were used to construct the biofuel cell, and its open-circuit potential (OCP) was tested. The results are as follows: Figure 15 As shown in the figure, the OCP of the interfering substances is significantly lower than that of CC and HQ, proving that the sensor has good anti-interference ability.

[0043] Interfering substances BPA, PhOH, SA, PNP, R, and benzoic acid (80 μM each), pesticide residues thiamethoxam, fipronil, imidacloprid, chlorothalonil, and thiamethoxam (1 μM each), and anions and cations Hg were added to nearshore seawater and river water samples. 2+ , Pb 2+ NO3 - SO4 2- Simulated wastewater samples were prepared using a spiking method (10 μM each). The results are shown in Table 1 below. The prepared sensor showed a recovery rate of 94.8–97.6% for hydroquinone with an RSD of less than 5.2% and a recovery rate of 91.7–104.2% for catechol with an RSD of less than 8.3%.

[0044] Table 1 The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, alterations, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A biofuel cell based on nickel-iron Prussian blue, characterized in that, The anode and cathode of the biofuel cell are both glassy carbon electrodes loaded with nickel-iron Prussian blue nanoparticles.

2. The biofuel cell based on nickel-iron Prussian blue construction according to claim 1, characterized in that, The biofuel cell based on nickel-iron Prussian blue is a dual-chamber H-type biofuel cell, with the anode chamber and cathode chamber separated by a proton exchange membrane. The anode electrolyte is a PBS buffer solution of catechol or hydroquinone, and the cathode electrolyte is a PBS buffer solution.

3. The biofuel cell based on nickel-iron Prussian blue construction according to claim 2, characterized in that, The proton exchange membrane is a DuPont Nafion 117 membrane.

4. The biofuel cell based on nickel-iron Prussian blue construction according to claim 2, characterized by, The concentration of the catechol or hydroquinone PBS buffer is 0.5 μM to 20 mM, and the pH value is 6 to 7; the pH value of the cathode electrolyte is 7 to 8.

5. The biofuel cell based on nickel-iron Prussian blue construction according to claim 1, characterized by, The preparation method of the nickel-iron Prussian blue nanoparticles is as follows: (1) Mix Ni(CH3COO)2 and C6H5Na3O7 in water to obtain solution A; (2) Add K3Fe(CN)6 solution to solution A, mix and age at room temperature to obtain nickel-iron Prussian blue nanoparticles.

6. The biofuel cell based on nickel-iron Prussian blue construction according to claim 5, characterized by, The molar ratio of Ni(CH3COO)2, C6H5Na3O7 and K3Fe(CN)6 is 1:1.2~1.3:0.6~0.8; the aging time at room temperature is 22-26 hours.

7. The biofuel cell based on nickel-iron Prussian blue construction according to claim 5, characterized by, In step (1), the concentration of Ni(CH3COO)2 in solution A is 29~32mM; in step (2), the concentration of K3Fe(CN)6 solution is 10~15mM.

8. A method for preparing a biofuel cell based on nickel-iron Prussian blue according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) The polished glassy carbon electrode was sonicated in water and anhydrous ethanol for 5-7 s respectively. 5-10 μL of nickel-iron Prussian blue nanoparticle solution with a concentration of 1-2 mg / mL was dropped onto the glassy carbon electrode. After drying, 1-3 μL of 0.02-0.05% Nafion was added to obtain the nickel-iron Prussian blue modified electrode. (2) The nickel-iron Prussian blue modified electrodes were used as the anode and cathode of the biofuel cell, respectively, and the anode electrolyte and cathode electrolyte were used to construct the biofuel cell.

9. The method for preparing a biofuel cell constructed from nickel-iron Prussian blue according to claim 8, characterized in that, The inner diameter of the glassy carbon electrode in step (1) is 2.8~3mm.

10. The application of the biofuel cell based on nickel-iron Prussian blue as described in any one of claims 1 to 7, or the biofuel cell based on nickel-iron Prussian blue prepared according to claim 8 or 9, in the detection of simulated wastewater containing catechol and / or hydroquinone.

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