A gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater

Abstract

The application discloses a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater, and relates to the technical field of environmental protection. The gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater is prepared by the following steps: ball milling of commercial bismuth oxide and appropriate yttrium oxide, gold spraying, and mercapto modification, so as to obtain hydroxyl-modified gold-yttrium co-doped bismuth oxide; then, the hydroxyl-modified gold-yttrium co-doped bismuth oxide and hydroxyl-modified C60 are mixed, and polyurethane reaction is carried out on modified foam nickel with surface modification of NiOOH, so as to form the gold-yttrium co-doped bismuth oxide composite electrode; compared with the commercial Bi2O3 electrode, the gold-yttrium co-doped bismuth oxide composite electrode has higher electrocatalytic degradation performance when being used for electrocatalytic degradation of printing and dyeing wastewater.

Description

TECHNICAL FIELD

[0001] The application relates to the field of environmental protection, and particularly relates to a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater. BACKGROUND

[0002] Water pollution is one of the main problems of environmental pollution, and the treatment of refractory organic wastewater is a key point, which includes coking wastewater, papermaking wastewater, pharmaceutical wastewater, printing and dyeing wastewater, domestic wastewater and agricultural wastewater, etc. The printing and dyeing wastewater is particularly concerned due to the characteristics of high colority, refractory, great environmental hazards, scattered production sites and difficult centralized treatment. The printing and dyeing wastewater mainly contains pollutants such as azo dyes, fluorescent whitening agents, polyvinyl alcohol and polyacrylate slurry, nitrogen-containing bleaching agents and aromatic amine dyes.

[0003] The advantage of electrochemical catalytic degradation of organic pollutants is to degrade non-biodegradable organic pollutants into biodegradable compounds, improve the efficiency of biological treatment, and improve the electrocatalytic efficiency of the electrode by constructing a three-dimensional electrode, which has become a research hotspot for electrocatalytic degradation of wastewater. Bi2O3 is a kind of semiconductor functional material, which is widely used in the fields of catalysis and photoelectric devices. Commercial Bi2O3 powder is often used as a negative electrode material for electrocatalytic degradation of various printing and dyeing wastewater.

[0004] Based on the search of the above-mentioned data, it is found that the electrode material currently used has general electrocatalytic degradation performance in the process of electrocatalytic degradation of printing and dyeing wastewater. Therefore, a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater is proposed, which realizes more efficient electrocatalytic degradation of printing and dyeing wastewater. SUMMARY

[0005] (I) Technical problems solved

[0006] In view of the deficiencies of the prior art, the application provides a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater, which solves the problem of general electrocatalytic degradation performance of the electrode material currently used in the process of electrocatalytic degradation of printing and dyeing wastewater.

[0007] (II) Technical scheme

[0008] In order to achieve the above object, the application is implemented by the following technical scheme: a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater, which comprises a gold-yttrium co-doped bismuth oxide composite electrode formed by polyurethane reaction of hydroxyl-modified gold-yttrium co-doped bismuth oxide and hydroxyl-modified C60 mixed with isophorone diisocyanate on modified foam nickel.

[0009] The application is further provided as follows: the preparation method of the gold-yttrium co-doped bismuth oxide composite electrode comprises the following steps:

[0010] Weigh 8.0-12.0 mg of hydroxyl-modified gold-modified yttrium-doped bismuth oxide, 1.0-1.5 mg of hydroxyl-modified C60, 0.9-1.4 mg of isophorone diisocyanate, and 80-100 μL of dibutyltin dilaurate acetone solution, ultrasonic dispersion for 2-5 minutes, and coat on the modified foam nickel surface. After drying, bake at 60-80℃ for 2-6 hours to obtain a gold and yttrium co-doped bismuth oxide composite electrode.

[0011] The application further provides that the dibutyltin dilaurate acetone solution contains 0.01-0.02 mg of dibutyltin dilaurate T-12.

[0012] The application further provides that the preparation method of the hydroxyl-modified gold and yttrium co-doped bismuth oxide comprises:

[0013] Add 100-150 mg of gold and yttrium co-doped bismuth oxide powder to 10-20 mL of ethanol and ultrasonic dispersion for 3-10 minutes, then add 5-10 mg of β-mercaptoethanol, and react at room temperature for 6-24 hours. Use a 0.22-micron microporous filter to filter, wash the filter cake with anhydrous ethanol for 3-5 times, and vacuum dry at 60-80℃ for 2-6 hours to obtain hydroxyl-modified gold and yttrium co-doped bismuth oxide.

[0014] The application further provides that the preparation method of the gold and yttrium co-doped bismuth oxide powder comprises:

[0015] Weigh 1.5-2 g of commercial bismuth oxide and 0.02-0.2 g of commercial yttrium oxide, add 50 g of zirconium oxide grinding balls, and use a nanoball mill to ball mill at 300-500 r / min for 10-60 minutes to obtain yttrium-doped bismuth oxide powder containing oxygen defects.

[0016] Put the double-sided tape with a layer of yttrium-doped bismuth oxide powder on the surface into a small ion sputtering instrument, spray gold for 30-120 seconds, dissolve the glue with tetrahydrofuran, use a 0.22-micron microporous filter to filter, wash the filter cake with tetrahydrofuran for 3-5 times, and vacuum dry at 60-80℃ for 2-5 hours to obtain gold and yttrium co-doped bismuth oxide powder.

[0017] The application further provides that the preparation method of the modified foam nickel comprises:

[0018] Cut the foam nickel into 1 cm*4 cm as a working electrode, use a Pt wire electrode as a counter electrode, Ag / AgCl / saturated KCl as a reference electrode, and 1.0 M KOH as an electrolyte. The foam nickel is subjected to electrochemical treatment at 1.0-2.0 V by cyclic voltammetry, the scanning rate is 100 m V·s-1, and the foam nickel is cycled for 300 times to obtain foam nickel modified with surface NiOOH, that is, modified foam nickel.

[0019] (Three) beneficial effects

[0020] The application provides a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater.

[0021] The gold-yttrium co-doped bismuth oxide composite electrode is prepared by the following steps: ball milling, gold spraying and mercaptoization of commercial bismuth oxide and appropriate yttrium oxide, obtaining hydroxyl-modified gold-yttrium co-doped bismuth oxide, mixing the hydroxyl-modified gold-yttrium co-doped bismuth oxide and hydroxyl-modified C60, and performing polyurethane reaction on modified foam nickel with surface modification of NiOOH to form the gold-yttrium co-doped bismuth oxide composite electrode. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 The figure is a structural schematic diagram of the application;

[0023] Figure 2 The figure is a CV diagram of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 in the embodiment of the application;

[0024] Figure 3 The figure is a LSV curve schematic diagram of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 in the embodiment of the application;

[0025] Figure 4 The figure is an EIS curve schematic diagram of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 in the embodiment of the application;

[0026] Figure 5 The figure is an electrocatalytic degradation curve schematic diagram of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 on methyl orange in the embodiment of the application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application.

[0028] Please refer to Figures 1-5 The embodiment of the application provides the following technical solutions: a preparation method of a gold-yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater, specifically comprising the following steps:

[0029] S1, weighing 2g of commercial bismuth oxide and 0.2g of commercial yttrium oxide, adding 50g of zirconium oxide grinding balls, using a nanometer ball mill at 300r / min for 60 minutes to obtain yttrium-doped bismuth oxide powder Y-Bi2O3 containing oxygen defects;

[0030] S2, the surface is bonded with a layer of yttrium-doped bismuth oxide powder double-sided tape, put into a small ion sputtering instrument, spray gold for 120 seconds, use tetrahydrofuran to dissolve the glue, use 0.22 micron microporous filter membrane to extract, the filter cake is washed with tetrahydrofuran for 5 times, 80℃ vacuum drying for 4 hours, get gold yttrium co-doped bismuth oxide powder Au-Y-Bi2O3;

[0031] S3, 150mg gold yttrium co-doped bismuth oxide powder is added into 20mL ethanol and ultrasonic dispersed for 10 minutes, then 10mg β-mercaptoethanol is added, room temperature reaction for 24 hours, use 0.22 micron microporous filter membrane to extract, the filter cake is washed with anhydrous ethanol for 5 times, 80℃ vacuum drying for 6 hours, get hydroxyl modified gold yttrium co-doped bismuth oxide HO-Au-Y-Bi2O3;

[0032] S4, the foam nickel cut into 1cm*4cm as working electrode, Pt wire electrode as counter electrode, Ag / AgCl / saturated KCl as reference electrode, 1.0M KOH as electrolyte, using cyclic voltammetry method to foam nickel for 1.0-2.0V electrochemical treatment, scan rate is 100m V·s-1, cycle 300 times, get the surface modified NiOOH foam nickel, namely modified foam nickel NF-NiOOH;

[0033] S5, weigh 12.0mg hydroxyl modified gold modified yttrium doped bismuth oxide, 1.5mg hydroxyl modified C60, 1.4mg isophorone diisocyanate IPDI and 100μL dibutyltin dilaurate acetone solution, ultrasonic dispersion for 5 minutes, coated on the surface of modified foam nickel, dry at 80℃ for 6 hours, get gold yttrium co-doped bismuth oxide composite electrode Au-Y-Bi2O3-C60-FN.

[0034] Comparative experiment,

[0035] The electrochemical behavior of gold yttrium co-doped bismuth oxide composite electrode Au-Y-Bi2O3-C60-FN prepared by example one and control electrode (commercial Bi2O3) electrode is measured by CHI-660E equipment, electrochemical measurement uses three electrode system, 6M KOH solution or 0.5M Na2SO4 as electrolyte, Au-Y-Bi2O3-C60-FN composite electrode and Bi2O3 electrode as working electrode, Ag / AgCl / saturated KCl as reference electrode, 1cm 2 Pt wire electrode as counter electrode;

[0036] The preparation method of the control electrode Bi2O3 is as follows: 8.0-12.0 mg of commercial Bi2O3 is weighed, 30-50 μL of glue (containing 0.3-0.5 mg of polytetrafluoroethylene) and 1.0-1.5 mg of acetylene black are added, and the mixture is adjusted into a paste, which is then compressed on a foam nickel sheet cut into 1 cm*4 cm, and baked at 80-120 ℃ for 2-6 h to obtain the control electrode.

[0037] Further, in order to study the electrochemical performance of the Au-Y-Bi2O3-C60-FN composite electrode, the cyclic voltammetry (CV) test is performed, as shown in FIG. 2. Figure 2 As shown in FIG. 3, the CV curves of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 at a scan rate of 5 mV / s can clearly observe several redox peaks in the CV curve, which means that Au-Y-Bi2O3-C60-FN and commercial Bi2O3 both have typical redox performance, and a small peak at about -0.68 V can be obviously observed in the CV curve, which may be caused by the oxidation of some residual bismuth in the oxidation process, as shown in FIG. 4. Figure 2 As can be seen from FIG. 5, the redox peak current of Au-Y-Bi2O3-C60-FN is significantly higher than that of commercial Bi2O3, which is attributed to the unique nanostructure of the Au-Y-Bi2O3-C60-FN composite electrode.

[0038] Further, in order to study the electrocatalytic efficiency, the linear sweep voltammetry (LSV) curves of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 are tested and compared, and the key parameters for evaluating the electrode electrocatalytic performance, such as the hydrogen evolution overpotential, are obtained, as shown in FIG. 6. Figure 3 As shown in FIG. 7, which is the LSV curves of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 in 0.5 M Na2SO4 electrolyte, it can be seen that the hydrogen evolution overpotential of Au-Y-Bi2O3-C60-FN is -1.14 V, while that of commercial Bi2O3 is -1.17 V, and the hydrogen evolution overpotential of Au-Y-Bi2O3-C60-FN is smaller in value, and the catalytic activity is higher.

[0039] Further, the electrochemical impedance spectroscopy (EIS) curves of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 in 6 M KOH electrolyte are compared and studied by EIS, as shown in FIG. 8. Figure 4 As can be seen from FIG. 9, Au-Y-Bi2O3-C60-FN has a smaller semicircle radius in the high frequency region, and the smaller the radius, the smaller the internal resistance of the electrode, and the faster the electron transmission efficiency, thereby having higher catalytic performance.

[0040] During the experiment, the UV-Vis spectrometer UV-2700 was used to test the UV-Vis spectrum of the electrolyte containing methyl orange, and the changes of the UV-Vis spectrum of the electrolyte containing methyl orange with the electrochemical catalytic reduction time were observed.

[0041] As a preferred solution, in order to realize the judgment of the electrocatalytic degradation performance of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 on methyl orange, as shown in the attached Figure 5 As shown in the attached figure, the degradation conditions are 20 mg / L methyl orange in 0.5M Na2SO4 electrolyte, and constant voltage-1.4V. It can be seen that the degradation amounts of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 on methyl orange are 56.3% and 42.7% respectively at 30 minutes, and the degradation amounts of Au-Y-Bi2O3-C60-FN and commercial Bi2O3 on methyl orange are 83.6% and 65.4% respectively at 60 minutes. From the above data, it can be concluded that compared with the commercial Bi2O3 electrode, the Au-Y-Bi2O3-C60-FN composite electrode has higher electrocatalytic degradation ability of methyl orange.

[0042] In summary, after the commercial bismuth oxide is ball milled with appropriate yttrium oxide, gold spraying and mercapto modification, the hydroxyl modified gold yttrium co-doped bismuth oxide HO-Au-Y-Bi2O3 is obtained, then the HO-Au-Y-Bi2O3 and the hydroxyl modified C60 are mixed, and the polyurethane reaction is carried out with isophorone diisocyanate IPDI on the modified foam nickel with surface modified NiOOH to form the gold yttrium co-doped bismuth oxide composite electrode Au-Y-Bi2O3-C60-FN, and the electrocatalytic degradation performance thereof is studied in detail. The results show that compared with the commercial Bi2O3 electrode, the Au-Y-Bi2O3-C60-FN composite electrode has higher electrocatalytic degradation performance on methyl orange printing and dyeing wastewater.

Claims

1. A gold and yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater, characterized in that: The gold-yttrium co-doped bismuth oxide composite electrode is formed by polyurethane reaction of hydroxyl-modified gold-yttrium co-doped bismuth oxide and hydroxyl-modified C60 mixed with isophorone diisocyanate on modified foam nickel. ​ 2. The gold and yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater according to claim 1, characterized in that: The preparation method of the gold-yttrium co-doped bismuth oxide composite electrode comprises: 8.0-12.0 mg of hydroxyl-modified gold-modified yttrium-doped bismuth oxide, 1.0-1.5 mg of hydroxyl-modified C60, 0.9-1.4 mg of isophorone diisocyanate, and 80-100 μL of dibutyltin dilaurate acetone solution are weighed, ultrasonically dispersed for 2-5 minutes, coated on the surface of modified foam nickel, and then dried and baked at 60-80 °C for 2-6 hours to obtain the gold-yttrium co-doped bismuth oxide composite electrode.

3. The gold and yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater according to claim 2, characterized in that: The dibutyltin dilaurate acetone solution contains 0.01-0.02 mg of dibutyltin dilaurate T-12.

4. The gold and yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater according to claim 2, characterized in that: The preparation method of the hydroxyl-modified gold-yttrium co-doped bismuth oxide comprises: 100-150 mg of gold-yttrium co-doped bismuth oxide powder is added to 10-20 mL of ethanol and ultrasonically dispersed for 3-10 minutes, then 5-10 mg of β-mercaptoethanol is added, and the mixture is reacted at room temperature for 6-24 hours, filtered with a 0.22 micron microporous filter, the filter cake is washed with anhydrous ethanol for 3-5 times, and vacuum dried at 60-80 °C for 2-6 hours to obtain the hydroxyl-modified gold-yttrium co-doped bismuth oxide.

5. The gold and yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater according to claim 4, characterized in that: The preparation method of the gold-yttrium co-doped bismuth oxide powder comprises: 1.5-2 g of commercial bismuth oxide and 0.02-0.2 g of commercial yttrium oxide are weighed, 50 g of zirconium oxide grinding balls are added, and the mixture is ball milled at 300-500 r / min for 10-60 minutes using a nanoball mill to obtain yttrium-doped bismuth oxide powder containing oxygen defects; A double-sided adhesive tape with a layer of yttrium-doped bismuth oxide powder on the surface is placed in a small ion sputtering instrument, gold is sprayed for 30-120 seconds, the adhesive is dissolved in tetrahydrofuran, filtered with a 0.22 micron microporous filter, the filter cake is washed with tetrahydrofuran for 3-5 times, and vacuum dried at 60-80 °C for 2-5 hours to obtain the gold-yttrium co-doped bismuth oxide powder.

6. The gold and yttrium co-doped bismuth oxide composite electrode for electrocatalytic degradation of printing and dyeing wastewater according to claim 2, characterized in that: The preparation method of the modified foam nickel comprises: The foam nickel cut into 1 cm*4 cm is used as a working electrode, a Pt wire electrode is used as a counter electrode, an Ag / AgCl / saturated KCl is used as a reference electrode, and 1.0 M KOH is used as an electrolyte, and the foam nickel is electrochemically treated at 1.0-2.0 V by cyclic voltammetry at a scan rate of 100 m V·s-1, and the foam nickel is cycled for 300 times to obtain the foam nickel modified with surface-modified NiOOH, i.e., the modified foam nickel.

Images