A bismuth oxide nanowire composite electrode material, a composite electrode and application

Abstract

The application relates to a bismuth oxide nanowire composite electrode material, a composite electrode and application, the bismuth oxide nanowire composite electrode material is prepared by mixing ferrocene-based modified beta bismuth oxide nanowires and multi-walled carbon nanotubes grafted with ferrocene groups, drying after ball milling treatment by a nanoball mill; a preparation method of the ferrocene-based modified beta bismuth oxide nanowires comprises the following steps: after deionized water is adjusted to pH 4-6, KH560 is added, reaction is carried out at room temperature for 10-40 min, beta bismuth oxide nanowires are added, reaction is carried out at 50-80 DEG C for 2-5 h, ferrocene-based partially grafted linear polyethylene imine solution is added, reaction is continuously carried out at 50-80 DEG C for 2-5 h, then the reaction is stopped, filtration is carried out, water washing, ethanol washing and drying are carried out, and the ferrocene-based modified bismuth oxide nanowires and the carbon nanotube composite electrode material and the composite electrode are obtained; the ferrocene-based modified bismuth oxide nanowires and the carbon nanotube composite electrode material and the composite electrode are novel and have high efficient electrocatalytic degradation performance on printing and dyeing wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrochemical catalysis and sewage treatment, and particularly relates to a bismuth oxide nanowire composite electrode material, a composite electrode and application. BACKGROUND

[0002] Printing and dyeing wastewater contains pollutants such as azo dyes, optical brighteners, polyvinyl alcohol and polyacrylic slurry, nitrogen-containing bleaching agents, and aromatic amine dyes. Compared with other wastewater, printing and dyeing wastewater has the characteristics of high colority, difficulty in degradation, and great environmental hazards, and is classified as a refractory organic wastewater.

[0003] Electrochemical catalytic degradation technology can degrade non-biodegradable organic pollutants into biodegradable compounds, which is one of the important means to improve the efficiency of biological treatment of organic pollutants. At present, the commercially available catalytic electrode in the field of wastewater treatment is a Bi2O3 electrode, but it still needs to be improved for printing and dyeing wastewater. Since the concept of three-dimensional electrode was proposed by Backhurst et al. in the late 1960s, the electrocatalytic efficiency of the electrode has been improved by constructing a three-dimensional electrode, and it has gradually become a research hotspot for electrocatalytic degradation of organic wastewater.

[0004] Therefore, it is crucial to develop a new structure of bismuth oxide nanowire composite electrode material with high electrocatalytic efficiency and high degradation rate of organic pollutants, and to apply it to the treatment of printing and dyeing wastewater. SUMMARY

[0005] The present application aims to overcome the defects in the prior art and provides a bismuth oxide nanowire composite electrode material, a composite electrode and application, which has a regular nanowire and nanotube structure and has high electrocatalytic degradation performance for printing and dyeing wastewater, and can be applied to the electrocatalytic degradation of printing and dyeing wastewater.

[0006] To achieve the above-mentioned purpose, the technical solutions adopted by the present application are as follows:

[0007] A bismuth oxide nanowire composite electrode material is prepared by mixing ferrocene-based modified β-type bismuth oxide nanowires and multi-walled carbon nanotubes grafted with ferrocene groups in a mass ratio of 1-4:1, and then drying after ball milling treatment by a nanoball mill.

[0008] As a further technical solution, the ball milling time is 10-30 min,

[0009] As a further technical solution, the drying temperature is room temperature.

[0010] As a further technical solution, the preparation method of the ferrocene-based modified β-type bismuth oxide nanowires is as follows:

[0011] Step a, preparing β-type bismuth oxide nanowires;

[0012] Step b, preparing ferrocenyl moiety grafted linear polyethyleneimine;

[0013] Step c, preparing ferrocenyl moiety grafted linear polyethyleneimine solution: ferrocenyl moiety grafted linear polyethyleneimine is added into aqueous ethanol solution to prepare ferrocenyl moiety grafted linear polyethyleneimine solution with mass concentration of 10-50 g / L;

[0014] Step d, modification: first, deionized water is adjusted to pH 4-6, then silane coupling agent KH560 is added, and the reaction is carried out at room temperature for 10-40 min, then β-type bismuth oxide nanowires are added, and the reaction is carried out at 50-80 °C for 2-5 h under stirring, then ferrocenyl moiety grafted linear polyethyleneimine solution is added, and the reaction is continued at 50-80 °C for 2-5 h, then the reaction is stopped, and the solid is filtered, washed with water for 2-5 times, washed with ethanol for 2-5 times, and dried to obtain ferrocenyl modified β-type bismuth oxide nanowires.

[0015] As a further technical solution, in step c, the mass concentration of the aqueous ethanol solution is 75%;

[0016] As a further technical solution, in step d, the mass-volume ratio of deionized water, silane coupling agent, β-type bismuth oxide nanowires, and ferrocenyl moiety grafted linear polyethyleneimine is 20-40 mL: 10-25 mg: 0.05-0.1 g: 10-50 mg;

[0017] As a further technical solution, in step d, acetic acid is used to adjust the pH to 4-6;

[0018] As a further technical solution, in step d, the filtration uses a microporous filter membrane with a pore size of 0.22-0.45 microns;

[0019] As a further technical solution, in step d, the drying uses vacuum drying, and the vacuum drying temperature is 60 °C, and the time is 4-24 hours.

[0020] As a further technical solution, the preparation of β-type bismuth oxide nanowires uses metal oxide gas phase deposition technology.

[0021] A preparation method of a bismuth oxide nanowire composite electrode material, comprising the following steps:

[0022] Step 1, preparation of ferrocenyl modified β-type bismuth oxide nanowires:

[0023] Step 1-1: Prepare a ferrocene-based partially grafted linear polyethyleneimine solution: Add 10-50 mg of ferrocene-based partially grafted linear polyethyleneimine to a 75% ethanol aqueous solution to prepare a ferrocene-based partially grafted linear polyethyleneimine solution with a mass concentration of 10-50 g / L.

[0024] Steps 1-2, Modification: First, add 20-40 mL of deionized water to a 100 mL flask, adjust the pH to 4-6 with acetic acid, add 10-25 mg of silane coupling agent KH560, react at room temperature for 10-40 min, then add 0.05-0.10 g of β-bismuth oxide nanowires (β-Bi2O3 NW), react under magnetic stirring in an oil bath at 50-80ºC for 2-5 h, then add the ferrocene-based partially grafted linear polyethyleneimine solution prepared in Step 1, continue the reaction at 50-80ºC for 2-5 h, then stop the reaction, filter with a 0.22-0.45 μm microporous membrane, wash the solid with water 2-5 times, wash with ethanol 2-5 times, and then vacuum dry at 30-60ºC for 4-24 h to obtain ferrocene-based modified β-bismuth oxide nanowires;

[0025] Step 2, Preparation of composite electrode material: At room temperature, ferrocene-modified β-type bismuth oxide nanowires and ferrocene-grafted multi-walled carbon nanotubes are mixed at a mass ratio of 1-4:1, then ball-milled for 10-30 minutes using a nanoball mill, and dried at room temperature to obtain bismuth oxide nanowire composite electrode material (β-Bi2O3-Fc NW / CNT-Fc composite material).

[0026] A method for preparing a bismuth oxide nanowire composite electrode includes the following steps:

[0027] The bismuth oxide nanowire composite electrode material was mixed with glue and acetylene black to form a paste, which was then pressed onto a nickel foam sheet and baked at 100ºC for 10 hours to obtain the bismuth oxide nanowire composite electrode.

[0028] As a further technical solution, by weight, the bismuth oxide nanowire composite electrode material comprises 8 parts; the adhesive comprises 0.5 parts; and the acetylene black comprises 1.5 parts.

[0029] As a further technical solution, the adhesive is a 60 wt% polytetrafluoroethylene aqueous solution.

[0030] Application of the bismuth oxide nanowire composite electrode material or the bismuth oxide nanowire composite electrode prepared by the preparation method described above in the treatment of dyeing and printing wastewater.

[0031] In this invention,

[0032] 1) The structure of β-type bismuth oxide nanowires is shown in Equation 1:

[0033]

[0034] Formula 1

[0035] The structural formula of KH560 is shown in Formula 2:

[0036]

[0037] Formula 2

[0038] The structural formula of ferrocene-based partially grafted linear polyethyleneimine is shown in Formula 3:

[0039]

[0040] Formula 3

[0041] Synthetic route of ferrocene-based modified β-type bismuth oxide nanowires (β-Bi₂O₃-Fc NW):

[0042]

[0043] The structural formula of surface-grafted ferrocene-based multi-walled carbon nanotubes is shown in Formula 4:

[0044]

[0045] Formula 4

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] This invention presents the first preparation of a novel ferrocene-based modified bismuth oxide nanowire and carbon nanotube composite electrode material and electrode, named β-Bi₂O₃-Fc NW / CNT-Fc. Through structural and electrocatalytic performance studies, it was found that the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode prepared in this invention possesses a regular nanowire and nanotube structure and exhibits highly efficient electrocatalytic degradation performance for dyeing and printing wastewater. It can be applied to the electrocatalytic degradation of dyeing and printing wastewater, providing a new approach for developing efficient and low-cost electrodes for the electrocatalytic degradation of dyeing and printing wastewater. Attached Figure Description

[0048] Figure 1 Scanning electron microscope images of β-Bi2O3-Fc NW, CNT-Fc, and β-Bi2O3-Fc NW / CNT-Fc;

[0049] exist Figure 1 Middle, A: β-Bi2O3-Fc NW; B: CNT-Fc; C: β-Bi2O3-Fc NW / CNT-Fc;

[0050] Figure 2 The CV plots are shown for the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode and the commercially available Bi₂O₃ electrode in 6M KOH electrolyte at a scan rate of 10mV / s.

[0051] Figure 3 LSV curves of β-Bi2O3-Fc NW / CNT-Fc composite electrode and commercially available Bi2O3 electrode in 0.5M Na2SO4 electrolyte;

[0052] Figure 4 Electrochemical impedance spectroscopy of β-Bi2O3-Fc NW / CNT-Fc composite electrode and commercially available Bi2O3 electrode in 0.5M Na2SO4 electrolyte;

[0053] Figure 5 Electrocatalytic degradation curves of methyl orange by β-Bi2O3-Fc NW / CNT-Fc composite electrode and commercially available Bi2O3 electrode; Implementation

[0054] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] In this invention,

[0056] 1. The β-type bismuth oxide nanowires were prepared by metal oxide vapor deposition technology; the preparation process is described in the reference: Yongfu Qiu, Minlin Yang, Hongbo Fan, Yuanzhi Zuo, Youyuan Shao, Yongjun Xu, Xiaoxi Yang and Shihe Yang, “Nanowires of α- and β-Bi2O3: phase-selective synthesis and application in photocatalysis” CrystEngComm, 2011, 13(6), 1843-1850;

[0057] The bismuth oxide nanowires have a diameter and length of approximately 10 nanometers and tens of micrometers, grow along the

[101] crystal plane, have a specific surface area of ​​7.34 m2 / g, and a hydroxyl content of 0.1-1.0 wt%.

[0058] 2. The ferrocene-based partially grafted linear polyethyleneimine is prepared by reacting ferrocene carboxylic acid with linear polyethyleneimine;

[0059] The preparation process can be found in the reference: Zain-Ul-Abdin, Li Wang, Haojie Yu, Muhammad Saleem, Muhammad Akram, Nasir M Abbasi, Khalid Hamad, Ruoli Sun, Yongsheng Chen, “Ferrocene-based polyethyleneimines for burning rate catalysts”, NEW JOURNAL OF CHEMISTRY, 2016, 40, 4, 3155-3163;

[0060] The linear polyethyleneimine has a weight-average molecular weight of 25,000 g / mol; the ferrocene-based grafting rate of the ferrocene-based portion of the linear polyethyleneimine is 70%.

[0061] 3. Surface-grafted ferrocenyl-based multi-walled carbon nanotubes, the preparation method of which can be found in the reference: Yongfu Qiu, Xiaoting Wang, Huizhen Huang, Zhiyu Cheng, Xueyi Chang, Lin Guo, “Ferrocenyl-functionalized carbon nanotubes with greatly improved surface reactivity for enhancing electrocapacitance” Journal of Organometallic Chemistry, 2019, 880, 349-354;

[0062] 4. Commercial bismuth oxide (Bi2O3, used as a reference sample), analytical grade, purchased from Maclean's Reagent Factory, for direct use;

[0063] 5. Silane coupling agent KH560 (Dow Corning Z-6040, USA), purchased from Shenzhen Huicheng Plastic Additives & Chemicals Co., Ltd., for direct use;

[0064] 6. Methyl orange (C 14 H 14 N3NaO3S (analytical grade), anhydrous sodium sulfate (Na2SO4, analytical grade), and potassium hydroxide (KOH, 95%) were all purchased from Maclean's Reagent Factory and used directly.

[0065] 7. Acetylene black (chemically pure) was purchased from Suzhou Shengernuo Technology Co., Ltd. and used directly.

[0066] 8. Polytetrafluoroethylene (analytical grade) was purchased from Beijing Chemical Plant and used directly.

[0067] 9. The high-purity water is obtained through Millipore purification equipment, with a resistivity ≥18.2 MΩ.cm.

[0068] Unless otherwise specified, all other raw materials are commercially available.

[0069] The present invention will now be described in further detail with reference to the accompanying drawings. Example

[0070] A bismuth oxide nanowire composite electrode material, the preparation method of which includes the following steps:

[0071] Step 1: Preparation of ferrocene-based modified β-type bismuth oxide nanowires:

[0072] Step 1-1: Prepare a ferrocene-based partially grafted linear polyethyleneimine solution: Add 35 mg of ferrocene-based partially grafted linear polyethyleneimine to a 75% ethanol aqueous solution to prepare a ferrocene-based partially grafted linear polyethyleneimine solution with a mass concentration of 25 g / L.

[0073] Steps 1-2, Modification: First, 30 mL of deionized water was added to a 100 mL flask. The pH was adjusted to 5.0 with acetic acid, and then 10–25 (17.5) mg of silane coupling agent KH560 was added. After reacting at room temperature for 30 min, 0.075 g of β-bismuth oxide nanowires (β-Bi2O3 NW) were added. The mixture was then reacted under magnetic stirring in an oil bath at 65°C for 3.5 h. Then, the ferrocene-based partially grafted linear polyethyleneimine solution prepared in Step 1 was added. The reaction was continued at 65°C for another 3.5 h. The reaction was then stopped, and the mixture was filtered through a 0.45 μm microporous membrane. The solid was washed four times with water and four times with ethanol, and then vacuum dried at 45°C for 15 h to obtain ferrocene-based modified β-bismuth oxide nanowires; the yield was 70.5%.

[0074] Step 2, Preparation of composite electrode material: At room temperature, ferrocene-modified β-type bismuth oxide nanowires and ferrocene-grafted multi-walled carbon nanotubes were mixed at a mass ratio of 7:3, ball-milled for 20 minutes in a nanoball mill, and dried at room temperature to obtain bismuth oxide nanowire composite electrode material (β-Bi2O3-Fc NW / CNT-Fc composite material).

[0075] A bismuth oxide nanowire composite electrode, the preparation method of which includes the following steps:

[0076] Weigh 8 mg of the β-Bi2O3-Fc NW / CNT-Fc composite material prepared above, add 0.5 mg of glue (60 wt% polytetrafluoroethylene aqueous solution) and 1.5 mg of acetylene black to it, mix into a paste, press it onto a nickel foam sheet (cut into 1 cm × 5 cm), and bake at 100°C for 10 h to obtain a bismuth oxide nanowire composite electrode (β-Bi2O3-Fc NW / CNT-Fc composite electrode), which is used as the working electrode. Example

[0077] A bismuth oxide nanowire composite electrode material, the preparation method of which includes the following steps:

[0078] Step 1: Preparation of ferrocene-based modified β-type bismuth oxide nanowires:

[0079] Step 1-1: Prepare a ferrocene-based partially grafted linear polyethyleneimine solution: Add 10 mg of ferrocene-based partially grafted linear polyethyleneimine to a 75% ethanol aqueous solution to prepare a ferrocene-based partially grafted linear polyethyleneimine solution with a mass concentration of 22 g / L.

[0080] Steps 1-2, Modification: First, add 20 mL of deionized water to a 100 mL flask, adjust the pH to 4.5 with acetic acid, then add 10 mg of silane coupling agent KH560. After reacting at room temperature for 20 min, add 0.05 g of β-bismuth oxide nanowires (β-Bi₂O₃ NW). React under magnetic stirring in an oil bath at 55°C for 4.5 h. Then, add the ferrocene-based partially grafted linear polyethyleneimine solution prepared in Step 1, and continue reacting at 55°C for another 4.5 h. Stop the reaction, filter through a 0.45 μm microporous membrane, wash the solid three times with water and three times with ethanol, and then vacuum dry at 40°C for 19 h to obtain ferrocene-modified β-bismuth oxide nanowires; yield 72.4%.

[0081] Step 2, Preparation of composite electrode material: At room temperature, ferrocene-modified β-type bismuth oxide nanowires and ferrocene-grafted multi-walled carbon nanotubes were mixed at a mass ratio of 8:2, ball-milled for 10 minutes in a nanoball mill, and dried at room temperature to obtain bismuth oxide nanowire composite electrode material (β-Bi2O3-Fc NW / CNT-Fc composite material).

[0082] A bismuth oxide nanowire composite electrode is prepared using the same method as in Example 1. Example

[0083] A bismuth oxide nanowire composite electrode material, the preparation method of which includes the following steps:

[0084] Step 1: Preparation of ferrocene-based modified β-type bismuth oxide nanowires:

[0085] Step 1-1: Prepare a ferrocene-based partially grafted linear polyethyleneimine solution: Add 50 mg of ferrocene-based partially grafted linear polyethyleneimine to a 75% ethanol aqueous solution to prepare a ferrocene-based partially grafted linear polyethyleneimine solution with a mass concentration of 30 g / L.

[0086] Steps 1-2, Modification: First, add 40 mL of deionized water to a 100 mL flask, adjust the pH to 5.5 with acetic acid, then add 25 mg of silane coupling agent KH560. After reacting at room temperature for 40 min, add 0.10 g of β-bismuth oxide nanowires (β-Bi₂O₃ NW). React under magnetic stirring in an oil bath at 75°C for 2.5 h. Then, add the ferrocene-based partially grafted linear polyethyleneimine solution prepared in Step 1, and continue reacting at 75°C for another 2.5 h. After stopping the reaction, filter through a 0.45 μm microporous membrane. Wash the solid 5 times with water and 5 times with ethanol, then vacuum dry at 55°C for 10 h to obtain ferrocene-based modified β-bismuth oxide nanowires; the yield is 70.7%.

[0087] Step 2, Preparation of composite electrode material: At room temperature, ferrocene-modified β-type bismuth oxide nanowires and ferrocene-grafted multi-walled carbon nanotubes were mixed at a mass ratio of 5:5, ball-milled for 30 minutes in a nanoball mill, and dried at room temperature to obtain bismuth oxide nanowire composite electrode material (β-Bi2O3-Fc NW / CNT-Fc composite material).

[0088] A bismuth oxide nanowire composite electrode is prepared using the same method as in Example 1.

[0089] The β-Bi₂O₃-Fc NW, CNT-Fc, and β-Bi₂O₃-Fc NW / CNT-Fc of Example 1 were examined using a JSM-6701F scanning electron microscope from NJE Inc. The results are shown in the table below. Figure 1 ;

[0090] from Figure 1 It can be seen that: Figure 1 TEM images of Aβ-type bismuth oxide nanowires show that the ferrocene-modified β-type bismuth oxide nanowires (β-Bi₂O₃-Fc NW) are ultrafine nanowires with good diameter uniformity, and their diameter and length are approximately 10 nm and tens of micrometers, respectively. Figure 1 TEM images of ferrocene-modified multi-walled carbon nanotubes (B-type) show uniformly distributed ferrocene-based conjugated carbon nanotubes; while from... Figure 1The SEM image of the C β-Bi2O3-Fc NW / CNT-Fc composite material shows that after β-Bi2O3-Fc NW and CNT-Fc are mixed and dispersed by ball milling in a certain proportion, the structure of the nanowires and nanotubes remains intact, which provides structural support for its high-efficiency electrocatalytic performance.

[0091] 1. Electrochemical performance testing:

[0092] To investigate the electrochemical performance of the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode, cyclic voltammetry (CV) was performed on the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode prepared in Example 1 and a commercially available Bi₂O₃ electrode, respectively. The results are shown in [Figure 1]. Figure 2 ;

[0093] Figure 2 The CV plots are shown for the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode and the reference electrode (commercial Bi₂O₃) at a scan rate of 10 mV / s; from Figure 2 Several redox peaks can be clearly observed in the CV curves, which means that both β-Bi2O3-Fc NW / CNT-Fc and commercial Bi2O3 have typical redox properties. A small peak at about -0.68V can be clearly observed in the CV curves, which may be due to the oxidation of some residual bismuth during the oxidation process.

[0094] In addition, from Figure 2 It can also be seen that the redox peak current of β-Bi2O3-Fc NW / CNT-Fc is significantly higher than that of commercial Bi2O3, which is attributed to the unique nanostructure of β-Bi2O3-Fc NW / CNT-Fc.

[0095] 2. Hydrogen evolution overpotential:

[0096] To investigate the electrocatalytic efficiency of the electrode, linear sweep voltammetry (LSV) curves of the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode and a reference electrode (commercially available Bi₂O₃ electrode) were compared to obtain the hydrogen evolution overpotential, a key parameter for evaluating the electrocatalytic performance of the electrode. The results are shown in [Figure number missing]. Figure 3 ;

[0097] Figure 3 The LSV curves for β-Bi₂O₃-Fc NW / CNT-Fc and commercial Bi₂O₃ in 0.5M Na₂SO₄ electrolyte are shown below. Figure 3It can be seen that the hydrogen evolution overpotential of the β-Bi2O3-Fc NW / CNT-Fc composite electrode is -1.12V, while the hydrogen evolution overpotential of the commercial Bi2O3 electrode is -1.134V. The β-Bi2O3-Fc NW / CNT-Fc composite electrode has a smaller hydrogen evolution overpotential and higher catalytic activity.

[0098] 3. Electrochemical impedance spectroscopy

[0099] To investigate the electrocatalytic efficiency of the electrode, the resistance of the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode and the reference electrode (commercial Bi₂O₃) were compared and tested; the results are shown in [Figure number missing]. Figure 4 ;

[0100] Figure 4 EIS curves of the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode and the reference electrode (commercial Bi₂O₃) in 0.5 M Na₂SO₄ electrolyte; from Figure 4 As we can see, the β-Bi2O3-Fc NW / CNT-Fc composite electrode has a smaller semi-circular radius in the high-frequency region. The smaller the radius, the smaller the internal resistance of the electrode, resulting in faster electron transport efficiency and thus more efficient catalytic performance.

[0101] Using a 20 mg / L methyl orange solution as a standard for dyeing and printing wastewater, the β-Bi₂O₃-Fc NW / CNT-Fc composite electrode prepared in Example 1 and a commercially available Bi₂O₃ electrode were used as working electrodes, respectively, along with a calomel electrode and a platinum sheet electrode (1 cm²). 2 Electrolysis experiments were conducted on methyl orange solution using 20 mg / L methyl orange as the reference and counter electrodes, respectively. The results were obtained using a SHIMADZU UV-2700 UV-Vis spectrophotometer. The UV-Vis spectrum of the 20 mg / L methyl orange solution was irradiated for different durations using a Philips 254 nm 6W UV lamp, and the changes in UV-Vis spectrum with UV irradiation time were observed. The electrocatalytic degradation curves were then obtained. The results are shown in [Figure number missing]. Figure 5 ;

[0102] Figure 5 The figures show the electrocatalytic degradation curves of methyl orange by the β-Bi2O3-Fc NW / CNT-Fc composite electrode and the commercial Bi2O3 electrode, respectively. The degradation conditions were 20 mg / L methyl orange in 0.5 M Na2SO4 electrolyte and a constant voltage of -1.4 V.

[0103] from Figure 5It can be seen that at 30 minutes, the degradation rates of methyl orange by β-Bi2O3-Fc NW / CNT-Fc and Bi2O3 were 76.1% and 37.6%, respectively, and at 60 minutes, the degradation rates were 95.7% and 64.8%, respectively. From the above data, it can be concluded that compared with the commercial Bi2O3 electrode, the β-Bi2O3-Fc NW / CNT-Fc composite electrode has a more efficient electrocatalytic degradation ability of methyl orange.

[0104] The embodiments described above are merely preferred embodiments of the present invention, and not an exhaustive list of all possible implementations of the present invention. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present invention should be considered to be included within the scope of protection of the claims of the present invention.

Claims

1. A bismuth oxide nanowire composite electrode material, characterized in that, The mixture was prepared by mixing ferrocene-modified β-type bismuth oxide nanowires and ferrocene-grafted multi-walled carbon nanotubes at a mass ratio of 1-4:1, followed by ball milling and drying. The preparation method of the ferrocene-based modified β-type bismuth oxide nanowires is as follows: Step a: Prepare β-type bismuth oxide nanowires; Step b: Prepare ferrocene-based partially grafted linear polyethyleneimine; Step c: Prepare a ferrocene-based partially grafted linear polyethyleneimine solution: Add the ferrocene-based partially grafted linear polyethyleneimine to an ethanol aqueous solution to prepare a ferrocene-based partially grafted linear polyethyleneimine solution with a mass concentration of 10-50 g / L. Step d, Modification: First, adjust the pH of deionized water to 4-6, add silane coupling agent KH560, react at room temperature for 10-40 min, then add β-type bismuth oxide nanowires, and react at 50-80 ºC for 2-5 h with stirring. Then add ferrocene-based partially grafted linear polyethyleneimine solution, and continue reacting at 50-80 ºC for 2-5 h. After that, stop the reaction, filter, wash the solid with water 2-5 times, wash with ethanol 2-5 times, and dry to obtain ferrocene-based modified β-type bismuth oxide nanowires.

2. The bismuth oxide nanowire composite electrode material according to claim 1, characterized in that, The ball milling time is 10-30 minutes, and the drying temperature is room temperature.

3. The bismuth oxide nanowire composite electrode material according to claim 1, characterized in that, In step c, the mass concentration of the ethanol-water solution is 75%; In step d, the mass-to-volume ratio of deionized water, silane coupling agent, β-bismuth oxide nanowires, and ferrocene-based partially grafted linear polyethyleneimine is 20-40 mL: 10-25 mg: 0.05-0.1 g: 10-50 mg. Adjust the pH to 4-6 using acetic acid; Vacuum filtration uses a microporous membrane with a diameter of 0.22–0.45 micrometers; The drying process employs vacuum drying at a temperature of 60 ºC for 4–24 hours.

4. The bismuth oxide nanowire composite electrode material according to claim 1, characterized in that, The β-type bismuth oxide nanowires were prepared using metal oxide vapor deposition technology.

5. A method for preparing a bismuth oxide nanowire composite electrode, characterized in that, Includes the following steps: The bismuth oxide nanowire composite electrode material as described in any one of claims 1-4 is mixed with adhesive and acetylene black to form a paste, pressed onto a nickel foam sheet, and baked at 100ºC for 10 hours to obtain the bismuth oxide nanowire composite electrode.

6. The method for preparing a bismuth oxide nanowire composite electrode according to claim 5, characterized in that, The bismuth oxide nanowire composite electrode material comprises 8 parts by weight. The glue content is 0.5 parts; the acetylene black content is 1.5 parts; The adhesive is a 60 wt% aqueous solution of polytetrafluoroethylene.

7. The application of a bismuth oxide nanowire composite electrode material as described in any one of claims 1-4 or a bismuth oxide nanowire composite electrode prepared by the preparation method as described in any one of claims 5-6 in the treatment of dyeing and printing wastewater.

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