Preparation and application method of electrode for electrochemical vat dyeing of vat dyes

Abstract

The application discloses a kind of preparation and application method of vat dye electrochemical vat dyeing electrode, comprising the following steps: step one, copper foil is pretreated using electrochemical polishing: step two, using quartz tube in CVD furnace as reaction chamber, temperature is pre-calibrated: step three, copper foil is placed into reaction chamber and vacuumized: step four, tube furnace is heated and copper foil is annealed under set pressure for 10 minutes: step five, after annealing, gas pressure is increased, 10sccm CH4 is introduced to grow carbon nanotube, after growth, copper foil is removed and cooled: step six, 1nm Fe catalyst is sequentially deposited on the surface of grown graphene on top of graphene, then buffer layer is evaporated by electron beam: step seven, carbon nanotube array is grown on G / Fe / Al2O3 surface, substrate G / Fe / Al2O3 is annealed, while tungsten wire is ignited to 30W to start growing carbon nanotube: step eight, preparation is completed, sample is taken out, solve the problem of low current efficiency, long reduction time, low dye reduction rate and poor dyeing effect of traditional process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrochemical materials and their applications, in particular to a preparation and application method of a reduced dye electrochemical reduction dyeing electrode. BACKGROUND

[0002] In traditional textile dyeing and finishing processes, a large amount of energy and chemical auxiliaries are consumed, and there are serious problems such as complex process, large wastewater discharge and environmental pollution. Therefore, people began to try to use electrochemical technology to innovate and replace the process, and to solve the long-standing problems in the dyeing, finishing and wastewater decolorization processes of traditional textiles, aiming to open up a new path for the ecologicalization of textile dyeing and finishing technology.

[0003] At present, electrode materials play a key role in electrochemical technology, and their performance directly determines the treatment effect of electrochemical technology. Carbon nanotubes and graphene materials are good electrode materials. Carbon nanotubes and graphene are important members of the carbon nanomaterial family with six aromatic structures, and have excellent properties such as excellent mechanical strength, high carrier mobility, high thermal and electrical conductivity, and large specific surface area. Therefore, graphene and carbon nanotubes are widely used in energy storage, transistor devices, sensors and other fields.

[0004] At present, the traditional technology applies carbon nanotubes to the surface of metal by first preparing carbon nanotubes and then transferring them to the metal substrate. This transfer process can cause damage to the carbon nanotubes. Therefore, growing carbon nanotubes directly on the surface of metal has always been a technical challenge. In recent years, although the technology of growing carbon nanotubes on the surface of metal has been developed and improved, for example, the Chinese authorized patent with the publication number CN104036878B, "Preparation method of graphene and carbon nanotube three-dimensional structure material", includes the following steps: (1) preparing a growth substrate of graphene; (2) growing graphene on the growth substrate of graphene prepared in step (1) by using chemical vapor deposition method; optionally, (3) transferring and patterning the graphene; (4) preparing a carbon nanotube growth catalyst; (5) growing carbon nanotubes. Although this preparation method can obtain an in-situ grown graphene and carbon nanotube three-dimensional structure, there are still some problems, such as low utilization rate of the interface contact area between the metal and the carbon nanotubes, and therefore it does not meet the existing needs. Therefore, we propose a preparation and application method of a reduced dye electrochemical reduction dyeing electrode. SUMMARY

[0005] The purpose of the present application is to provide a preparation and application method of a reduced dye electrochemical reduction dyeing electrode to solve the problems of low current efficiency, long reduction time, low dye reduction rate and poor dyeing effect of the traditional process mentioned in the background technology.

[0006] To achieve the above object, the present application provides the following technical scheme: a preparation of a vat dye electrochemical reduction dyeing electrode, comprising the following steps:

[0007] Step one, pretreat the copper foil by electrochemical polishing;

[0008] Step two, use the quartz tube in the CVD furnace as the reaction chamber, and use the K-type thermocouple probe to pre-calibrate the temperature;

[0009] Step three, put the copper foil into the reaction chamber, and vacuumize the quartz tube to 2.2 Pa;

[0010] Step four, raise the tubular furnace to 1000 DEG C, and introduce 300 sccm H2 under the pressure of 4.6*10 4 Pa to anneal the copper foil for 10 minutes;

[0011] Step five, after annealing, increase the total gas pressure in the reaction chamber to 4.7*10 4 Pa, keep the H2 flow unchanged, introduce 10 sccm CH4 to grow graphene for 15 min, and then quickly take out the copper foil and cool it to room temperature under the protection of hydrogen;

[0012] Step six, sequentially deposit 1 nm Fe catalyst on the top of graphene and then 3 nm Al2O3 buffer layer on the top of the Fe catalyst by electron beam evaporation;

[0013] Step seven, grow carbon nanotube array on the surface of G / Fe / Al2O3 by chemical vapor deposition method, and the growth conditions are as follows: introduce 2 sccm C2H2 and 210 sccm H2, anneal the substrate G / Fe / Al2O3 under the condition of 3.3*10

[0014] Step eight, after the preparation is completed, take out the sample.

[0015] Preferably, the size specification of the copper foil in step one is 2*25 cm.

[0016] Application of the vat dye electrochemical reduction dyeing electrode in textile dyeing, comprising the following steps:

[0017] Step 1, prepare the cathode electrolyte and the anode electrolyte respectively;

[0018] Step 2, fix the vat dye electrochemical reduction dyeing electrode as the cathode and the graphite electrode as the anode in the electrolytic cell;

[0019] Step 3, the anode and cathode electrolyte are added into the electrolytic cell, and the indirect electrochemical reduction complex system of the above-mentioned vat dye is used as the medium to carry out the reduction reaction under the protection of the protective gas, the electrolytic reduction temperature is 25-75 DEG C, the electrolytic voltage is 3.50V, the electrolytic current is mA, and the power reduction is carried out for 1-2 hours.

[0020] Preferably, the step 1 is carried out under the alkaline condition, the Fe II salt is mixed with the gluconate reagent to obtain the indirect electrochemical reduction complex system of the indigo dye, which is used as the cathode electrolyte of the electrochemical electrolytic dyeing experiment, wherein the content of the Fe II salt is 0.05-1 mol / L, the content of the gluconate is 0.075-1 mol / L, the molar ratio of the added amount of the Fe II to the added amount of the gluconate is 1:1-30, and the solvent is water.

[0021] Preferably, the Fe II salt is any one of ferrous sulfate, ferrous chloride and ferrous nitrate, and the gluconate is any one of sodium gluconate, calcium gluconate and zinc gluconate.

[0022] Preferably, the pH value of the complex system is 9-14, and the alkaline condition is provided by sodium hydroxide or potassium hydroxide.

[0023] Preferably, the anode electrolyte formula in the step 1 is composed of sodium hydroxide solution, sodium sulfite solution and sodium metabisulfite solution, and the content of the anode electrolyte solution is 0.1-2 mol / L.

[0024] Preferably, the protective gas in the step 3 is any one of nitrogen and argon.

[0025] Preferably, the initial concentration of the vat dye in the step 3 is 0.02-2 mol / L.

[0026] Preferably, the pH value of the alkaline condition in the step 3 is 9-14.

[0027] Compared with the prior art, the present application has the following beneficial effects:

[0028] 1. The present application solves the technical problem of growing carbon nanotubes directly on the metal surface by using graphene as the interface layer between the metal material and the carbon nanotube, which has good conductivity, low resistivity and excellent mechanical strength, thereby solving the problem of low utilization rate of the contact area of the carbon nanotube on the metal surface and forming a three-dimensional structure of graphene / carbon nanotube, which exhibits more excellent electrochemical performance.

[0029] 2, the application adopts chemical vapor deposition to prepare G / GNTs hybrid structure, first, multi-layer graphene is grown on copper foil by using chemical vapor deposition method with methane as carbon source; then Fe catalyst and Al2O3 buffer layer are deposited on the surface of graphene by using electron beam evaporation; finally, carbon nanotubes are grown by using chemical vapor deposition with acetylene as carbon source, and the carbon nanotubes are prepared into three-dimensional electrode material, which is applied to the reduction dye electrochemical reduction dyeing process, and excellent electrochemical performance and dyeing performance are shown, the reduction time of the dyeing process is shortened, the current efficiency is high, the fastness of dyeing is good, the dyeing effect is remarkable, and good application prospect is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0030] Fig. 1 It is a preparation schematic diagram of the graphene carbon nanotube three-dimensional structure of the application;

[0031] Fig. 2 It is a preparation method step diagram of the graphene carbon nanotube three-dimensional structure of the application;

[0032] Fig. 3 It is a step diagram of the electrode application method of the electrochemical reduction dyeing of the application. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application.

[0034] Reduction potential, current efficiency, dye reduction rate, dyeing K / S value, rubbing fastness, COD, BOD and the like.

[0035] The technical problem to be solved by the application is that the provided technical solution can realize basically no wastewater discharge, and can significantly improve the current efficiency, reduction rate, shorten the electrochemical reduction reaction time, improve the production efficiency of industrial production of the process, and the dyeing effect is equivalent to that of traditional sodium hydrosulfite dyeing. EMBODIMENT

[0036] Please refer to Figs. 1-3 An embodiment provided by the application is a preparation of a reduction dye electrochemical reduction dyeing electrode, including the following steps:

[0037] Step one, pretreat the copper foil by electrochemical polishing;

[0038] Step two, use the quartz tube in the CVD furnace as the reaction chamber, and use the K-type thermocouple probe to pre-calibrate the temperature;

[0039] Step three, place the copper foil into the reaction chamber, and vacuumize the quartz tube to 2.2 Pa;

[0040] Step four, the tube furnace is heated to 1000℃, 300sccm H2 is introduced at 4.6x10 4 Pa pressure, and the copper foil is annealed for 10 minutes;

[0041] Step five, after annealing, the total gas pressure in the reaction chamber is increased to 4.7x10 4 Pa, the H2 flow is kept unchanged, 10sccm CH4 is introduced to grow graphene for 15 minutes, after the graphene is grown, the copper foil is quickly pulled out and cooled to room temperature under the protection of hydrogen;

[0042] Step six, 1nm Fe catalyst is deposited on the top of the graphene in sequence on the surface of the grown graphene by electron beam evaporation, and then a 3nm Al2O3 buffer layer is deposited again by electron beam evaporation;

[0043] Step seven, carbon nanotube arrays are grown on the surface of G / Fe / Al2O3 by chemical vapor deposition, the growth conditions are that 2sccm C2H2 and 210sccm H2 are introduced, the substrate G / Fe / Al2O3 is annealed at 3.3x104Pa for 30s, and the tungsten filament is lit to 30W to start growing carbon nanotubes, and the pressure decreases to 665Pa during the growth process;

[0044] Step eight, the preparation is completed, and the sample is taken out.

[0045] Further, the size specification of the copper foil in step one is 2x25cm.

[0046] Application of the reduced dye electrochemical reduction dyeing electrode in textile dyeing: in 0.1mol / L sodium hydroxide aqueous solution, 0.02mol / L ferrous sulfate, 0.02mol / L sodium gluconate and 0.02mol / L indigo are added in sequence for sufficient stirring to obtain a cathode electrolyte, an anode electrolyte is 0.01mol / L sodium hydroxide solution, a cathode electrode is a graphene / carbon nanotube three-dimensional electrode, and an anode is a graphite electrode; the cathode and anode electrolytes are added into an electrolysis tank for reduction, the electrolytic reduction temperature is 25℃, the electrolytic voltage is 3.50V, the electrolytic current is mA, the power reduction is performed for 1 hour, the current efficiency is 17%, and when the indigo is completely converted into leucoindigo, the dyeing solution changes from an opaque solution to a transparent solution. Embodiment

[0047] A preparation of a reduced dye electrochemical reduction dyeing electrode, comprising the following steps:

[0048] Step one, the copper foil is pretreated by electrochemical polishing;

[0049] Step two, a quartz tube in a CVD furnace is used as a reaction chamber, and a K-type thermocouple probe is used for pre-calibration of the temperature;

[0050] Step three, put the copper foil into the reaction chamber, and vacuumize the quartz tube to 2.2 Pa;

[0051] Step four, heat the tube furnace to 1000℃, and introduce 300 sccm H2into the reaction chamber under the pressure of 4.6 x 104Pa to anneal the copper foil for 10 minutes; 4

[0052] Step five, after annealing, increase the total pressure in the reaction chamber to 4.7 x 104Pa, keep the H2flow unchanged, introduce 10 sccm CH4to grow graphene for 15 minutes, and then quickly pull out the copper foil and cool it to room temperature under the protection of hydrogen; 4

[0053] Step six, use electron beam evaporation to deposit 1 nm Fe catalyst on the top of the graphene, and then deposit 3 nm Al2O3buffer layer by electron beam evaporation again;

[0054] Step seven, use chemical vapor deposition method to grow carbon nanotube array on the surface of G / Fe / Al2O3, the growth conditions are as follows: introduce 2 sccm C2H2and 210 sccm H2, anneal the substrate G / Fe / Al2O3 under the condition of 3.3 x 104Pa for 30 seconds, and light the tungsten wire to 30 W to start growing carbon nanotubes, and the pressure decreases to 665 Pa during the growth process;

[0055] Step eight, after the preparation is completed, take out the sample.

[0056] Further, the size specification of the copper foil in step one is 2 x 25 cm.

[0057] In 2 mol / L aqueous sodium hydroxide solution, 0.075 mol / L ferrous sulfate, 0.075 mol / L calcium gluconate, and 0.0375 mol / L indigo are sequentially added and stirred to obtain a cathode electrolyte, and an anode electrolyte is 2 mol / L sodium hydroxide solution; the cathode electrode is a graphene / carbon nanotube three-dimensional electrode, and the anode is a graphite electrode; the cathode and anode electrolytes are respectively added to an electrolysis tank for reduction, the electrolytic reduction temperature is 25℃, the electrolytic voltage is 3.50V, the electrolytic current is mA, the power reduction is 1.5 hours, the current efficiency is 19%, and when the indigo is completely converted into leucoindigo, the dye solution changes from opaque solution to transparent solution.

[0058] ​​It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims with respect to the figures of the application.

Claims

1. Use of an electrode for the electrochemical reduction dyeing of vat dyes for the dyeing of textiles, characterized in that The application relates to an electrochemical vat dyeing electrode of a vat dye, a preparation method of the electrochemical vat dyeing electrode, and an electrochemical vat dyeing method. Step one: the copper foil is pretreated by electrochemical polishing, and the size of the copper foil is 2*25 cm; Step two: a quartz tube in a CVD furnace is used as a reaction chamber, and a K-type thermocouple probe is used for pre-calibration of temperature; Step three: the copper foil is placed into the reaction chamber, and the quartz tube is vacuumized to 2.2 Pa; Step four, the tube furnace was heated to 1000 °C, 300 sccm H2was introduced in 4.6 x 10 4 Copper foil was annealed at 1000 °C for 10 minutes under 4.6 x 10 Step five, after annealing, the total pressure in the reaction chamber was increased to 4.7 x 10 4 Pa, the H2flow was kept constant, 10 seem CH4was introduced to grow graphene for 15 min, after graphene growth, the copper foil was quickly pulled out and cooled to room temperature under H2protection; Step six: 1 nm Fe catalyst is deposited on the top of the graphene by electron beam evaporation, and then 3 nm Al2O3 buffer layer is deposited again by electron beam evaporation; Step seven: carbon nanotube arrays are grown on the G / Fe / Al2O3 surface by a chemical vapor deposition method, and the growth conditions are as follows: 2 sccm C2H2 and 210 sccm H2 are introduced, the substrate G / Fe / Al2O3 is annealed at 3.3*104 Pa for 30 s, meanwhile, a tungsten wire is lighted and adjusted to 30 W to start growing the carbon nanotube, and the pressure in the growing process is reduced to 665 Pa; Step eight: the preparation is completed, and the sample is taken out.

2. Use according to claim 1, characterized in that: The application relates to an electrochemical vat dyeing electrode of a vat dye, a preparation method of the electrochemical vat dyeing electrode, and an electrochemical vat dyeing method. Step 1: cathode electrolyte and anode electrolyte are prepared respectively, Fe II salt and gluconate reagent are mixed under alkaline conditions to obtain an indirect electrochemical reduction complex system of indigo dye, which is used as cathode electrolyte of electrochemical electrolytic dyeing experiment, the content of the Fe II salt is 0.05-1 mol / L, the content of the gluconate is 0.075-1 mol / L, the molar ratio of the added amount of the Fe II salt to the added amount of the gluconate is 1:1-30, and water is used as a solvent; the anode electrolyte is composed of sodium hydroxide solution, sodium sulfite solution and sodium metabisulfite solution, and the content of the anode electrolyte solution is 0.1-2 mol / L; Step 2: the electrochemical vat dyeing electrode of the vat dye is used as a cathode, and a graphite electrode is used as an anode and fixed in an electrolytic cell; Step 3: the cathode electrolyte and the anode electrolyte are added into the electrolytic cell, and the above-mentioned indirect electrochemical reduction complex system of the vat dye is used as a medium to carry out a reduction reaction under the protection of a protective gas, the electrolytic reduction temperature is 25-75 DEG C, the electrolytic voltage is 3.50 V, the electrolytic current is mA, and the power reduction lasts for 1-2 hours.

3. Use according to claim 2, characterized in that: The Fe II salt is any one of ferrous sulfate, ferrous chloride and ferrous nitrate, and the gluconate is any one of sodium gluconate, calcium gluconate and zinc gluconate.

4. Use according to claim 3, characterized in that: The pH value of the complex system is 9-14, and the alkaline condition is provided by sodium hydroxide or potassium hydroxide.

5. Use according to claim 2, characterized in that: The protective gas in step 3 is any one of nitrogen and argon.

6. Use according to claim 2, characterized in that: The initial concentration of the vat dye in step 3 is 0.02-2 mol / L.

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