A copper electrodeposition coating titanium anode and a preparation method and application thereof

Abstract

The application discloses a copper electrodeposition coating titanium anode and a preparation method and application thereof, and relates to the technical field of titanium anodes, in particular to a copper electrodeposition coating titanium anode and a preparation method and application thereof. The preparation method comprises the following steps: adding iridium source compounds, tantalum source compounds and strontium source compounds into organic alcohol according to the molar percentage of Ir:Ta: Sr=(70-x):30:x, and preparing a coating solution after ultrasonic dispersion; performing baking treatment on the rough titanium substrate after brushing the coating solution on the surface of the rough titanium substrate, so as to obtain a dry titanium substrate; performing heat treatment on the dry titanium substrate in an air atmosphere at 400-600 DEG C for a first predetermined time, so as to complete the coating of a coating layer; after repeating the coating for several times, placing the titanium substrate coated for the last time in a muffle furnace, and performing heat treatment on the titanium substrate in an air atmosphere at 400-600 DEG C for a second predetermined time, so as to prepare the copper electrodeposition coating titanium anode. The application adds strontium in the coating solution, and reduces the equivalent molar mass of iridium, so that the electrocatalytic activity of the prepared copper electrodeposition coating titanium anode is improved when the molar mass of strontium accounts for 10%, and the volt-ampere capacity is also increased with the increase of the amount of strontium.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of titanium anode, in particular to a copper electrodeposition coating titanium anode and a preparation method and application thereof. BACKGROUND

[0002] Titanium anode includes titanium substrate as current collector and oxide coating which plays catalytic activity, and its performance in copper electrodeposition anode such as electrolytic copper foil, electronic copper plating, copper electrodeposition recovery is closely related to surface morphology structure of substrate and coating composition. The electrocatalytic activity of titanium anode is generally derived from the mixed oxide on the surface, but since the titanium substrate is easily corroded by acidic electrolyte, the active oxide coating is required to have not only good catalytic activity but also high stability.

[0003] At present, most of the researches on insoluble anode in acidic copper electrodeposition system are focused on noble metals iridium and ruthenium, but in order to control the cost and facilitate commercialization and use, it is very important to reduce the content and cost of noble metal coating. In acidic electrolyte, the electrocatalytic activity of RuO2 is greater than that of IrO2, but the stability of IrO2 is greater than that of RuO2. Therefore, when preparing titanium anode, on the one hand, researchers often look for a suitable ratio of iridium oxide and ruthenium oxide; on the other hand, researchers look for the addition of new oxide components while taking iridium oxide as the main active substance, in order to improve the catalytic activity and control the cost. In high current density or high temperature working environment, the addition of inert components in the coating can even improve the service life. Therefore, whether it is to improve the catalytic activity and service life, or to reduce the cost of the coating, the preparation of multi-component oxide coating has high research value.

[0004] Therefore, the prior art still needs to be improved and developed. SUMMARY

[0005] In view of the deficiencies of the prior art, the purpose of the present application is to provide a copper electrodeposition coating titanium anode and a preparation method and application thereof, aiming at solving the problems of poor electrocatalytic activity and poor stability and high cost of the existing copper electrodeposition coating titanium anode.

[0006] The technical scheme of the present application is as follows:

[0007] A preparation method of a copper electrodeposition coating titanium anode, comprising the following steps:

[0008] Etching the initial titanium sheet to obtain a rough titanium substrate;

[0009] An iridium source compound, a tantalum source compound and a strontium source compound are added to an organic alcohol in a molar percentage of Ir:Ta: Sr = (70-x):30:x, and a coating liquid is prepared after ultrasonic dispersion, wherein 10≤x≤15;

[0010] After the coating liquid is uniformly brushed on the rough titanium substrate surface, baking treatment is performed to obtain a dry titanium substrate;

[0011] The dry titanium substrate is transferred to a muffle furnace, heated to 400-600℃ in an air atmosphere, and kept for a first predetermined time to complete the coating of the first coating layer;

[0012] After repeating the coating several times, the titanium substrate coated for the last time is placed in a muffle furnace, heated to 400-600℃ in an air atmosphere, and kept for a second predetermined time to obtain a copper electrodeposition coating titanium anode with a surface coating layer of IrO2-Ta2O5-SrO2.

[0013] The preparation method of the copper electrodeposition coating titanium anode, wherein the iridium source compound is H2IrCl6·6H2O, the tantalum source compound is tantalum ethoxide, the strontium source compound is strontium acetate, and the organic alcohol is one or more of n-butanol, ethanol, and propanol.

[0014] The preparation method of the copper electrodeposition coating titanium anode, wherein after the coating liquid is uniformly brushed on the rough titanium substrate surface, baking treatment is performed, which includes:

[0015] After the coating liquid is dipped with a brush, it is uniformly brushed on the rough titanium substrate surface, and the brushed rough titanium substrate is placed under an infrared lamp for baking for 30s to remove most of the solvent;

[0016] The brushed rough titanium substrate is then placed in a 100℃ drying oven for sufficient drying for 10min to obtain a dry titanium substrate.

[0017] The preparation method of the copper electrodeposition coating titanium anode, wherein the first predetermined time is 10min, and the second predetermined time is 60min.

[0018] The preparation method of the copper electrodeposition coating titanium anode, wherein an initial titanium sheet is subjected to etching treatment to obtain a rough titanium substrate, which includes:

[0019] After the initial titanium sheet is cut, it is subjected to alkaline cleaning and oil removal treatment to obtain a cut titanium sheet;

[0020] A double electrode system is formed by using NaBr as an electrolyte, using the cut titanium sheet as a working electrode, and using an initial titanium sheet as a counter electrode, and the double electrode system is powered on. First, a constant current of 180mA·cm -2 The cut titanium sheet is etched once, and then a constant current of 500mA·cm -2 The cut titanium sheet is etched twice to obtain the rough titanium substrate.

[0021] The application discloses a preparation method of a copper electro-deposition coating titanium anode, and relates to the technical field of titanium anodes.

[0022] Na3PO4·12H2O, Na2CO3 and NaOH are dissolved in deionized water in a mass ratio of 105:25:4 to prepare 0.3% alkali oil removal liquid, and the alkali oil removal liquid is heated to boiling for standby;

[0023] After the initial titanium sheet is cut, the titanium sheet is added into the boiling alkali oil removal liquid and kept for a predetermined time;

[0024] After the initial titanium sheet is taken out, the titanium sheet is washed with deionized water and ultrasonically cleaned in the deionized water, so that the alkali washing process is completed, and the cut titanium sheet is prepared.

[0025] The application further discloses a copper electro-deposition coating titanium anode prepared by the preparation method.

[0026] The application further discloses an application of the copper electro-deposition coating titanium anode.

[0027] Beneficial effects: by introducing metal strontium into the coating liquid, the application reduces the use amount of noble metal iridium in the same proportion, and prepares an IrO2-Ta2O5-SrO2 copper electro-deposition coating titanium anode; the electrochemical performances of titanium anodes with ratios of Ir: Sr = 70:0, Ir: Sr = 65:5, Ir: Sr = 60:10 and Ir: Sr = 55:15 (mol%) are compared, and phase morphology analysis is performed, and the following conclusions are obtained: according to the comparison of the electrochemical performances, it is found that when the strontium addition amount is 5%, the electrochemical performance is similar to the performance when the strontium addition amount is 0%, and the IrO2-Ta2O5-SrO2 copper electro-deposition coating titanium anode with a strontium addition amount of 10% has better catalytic activity than the IrO2-Ta2O5 copper electro-deposition coating titanium anode; according to the SEM graph and the electrochemical test, it can be inferred that the addition of strontium is beneficial to the increase of active sites on the surface of the copper electro-deposition coating titanium anode, the real area of the copper electro-deposition coating titanium anode is increased, and therefore the electro-catalytic activity of the copper electro-deposition coating titanium anode is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The application further discloses a preparation method of a copper electro-deposition coating titanium anode.

[0029] Figure 2 In the figure, a, b, c and d respectively represent SEM morphology graphs of the copper electro-deposition coating titanium anodes with strontium addition amounts of 0%, 5%, 10% and 15% (mol%).

[0030] Figure 3EDS figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with strontium molar ratio of 10%, wherein, a-e are element distribution figures.

[0031] Figure 4 XRD figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios.

[0032] Figure 5 a is the LSV activity curve figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios, b is the Tafel curve figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios.

[0033] Figure 6 a is the CV curve figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios, b is the cyclic voltammetry charge figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios.

[0034] Figure 7 The current-time curve figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios.

[0035] Figure 8 a is the EIS figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios, b is the EIS fitting figure and equivalent circuit figure of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with strontium addition of 10%.

[0036] Figure 9 The curve figure of the change of the cell voltage with electrolysis time of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios.

[0037] Figure 10 The bar chart of the accelerated electrolysis life of the titanium anode coated with copper electrodeposited iridium tantalum strontium oxide with different metal molar ratios.

[0038] Figure 11 a is the failure figure of the Sr0 / Ir70 electrode, b is the failure figure of the Sr5 / Ir65 electrode, c is the failure figure of the Sr10 / Ir60 electrode, d is the failure figure of the Sr15 / Ir55 electrode.

[0039] Figure 12 a is the micro-morphology figure of the bonding surface of the pure titanium cathode, b is the micro-morphology figure of the surface of the grain growth in the solution.

[0040] Figure 13 The stress-strain curve figure of the electrolytic copper foil. DETAILED DESCRIPTION

[0041] The application provides a copper electrodeposition coating titanium anode and a preparation method and application thereof.

[0042] Figure 1 A preparation method of the copper electrodeposition coating titanium anode provided by the application is shown in a flow chart, which comprises the following steps:

[0043] S10, electrochemical etching treatment is performed on the initial titanium sheet to obtain a rough titanium substrate;

[0044] S20, iridium source compounds, tantalum source compounds and strontium source compounds are added into organic alcohol according to a molar percentage of Ir:Ta: Sr=(70-x):30:x, and a coating solution is prepared after ultrasonic dispersion, wherein 10≤x≤15;

[0045] S30, the coating solution is uniformly brushed on the surface of the rough titanium substrate, and then baking treatment is performed to obtain a dry titanium substrate;

[0046] S40, the dry titanium substrate is transferred into a muffle furnace, heated to 400-600 DEG C under an air atmosphere, and kept for a first predetermined time to complete the coating of a coating layer;

[0047] S50, after repeated coating for several times, the titanium substrate coated for the last time is placed in a muffle furnace, heated to 400-600 DEG C under an air atmosphere, and kept for a second predetermined time to obtain a copper electrodeposition coating titanium anode with a surface coating layer of IrO2-Ta2O5-SrO2.

[0048] In this embodiment, the use amount of the noble metal iridium is reduced, a certain molar mass of strontium is added into the coating solution on the basis of the iridium-tantalum coating oxide anode, and the equivalent molar mass of iridium is reduced. It is found through preliminary research that the electrocatalytic activity of the IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anode prepared by the thermal decomposition method is improved when the molar mass of strontium accounts for 10%, and the voltammetric capacity is also increased with the increase of the addition amount of strontium.

[0049] Specifically, the embodiment reduces the use of noble metal iridium by introducing metal strontium into the coating liquid in the same proportion, prepares IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anodes, and compares the electrochemical properties of titanium anodes with ratios of Ir: Sr = 70:0, Ir: Sr = 65:5, Ir: Sr = 60:10, Ir: Sr = 55:15 (mol %), etc. Phase morphology analysis, etc. The following conclusions are drawn: the comparison of electrochemical properties shows that when the strontium addition amount is 5%, the electrochemical performance is similar to that when the strontium addition amount is 0%, and the IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anode with a strontium addition amount of 10% can obtain better catalytic activity than the IrO2-Ta2O5 copper electrodeposition coating titanium anode. Combined with SEM images and electrochemical tests, it can be inferred that the addition of strontium is beneficial to the increase of active sites on the surface of the copper electrodeposition coating titanium anode, increases the real area of the copper electrodeposition coating titanium anode, and thus improves the electrocatalytic activity of the copper electrodeposition coating titanium anode.

[0050] In some embodiments, the iridium source compound is H2IrCl6·6H2O, the tantalum source compound is tantalum ethoxide, and the strontium source compound is strontium acetate.

[0051] In some embodiments, the coating liquid is uniformly brushed on the rough titanium substrate surface and then subjected to baking treatment, including: the coating liquid is dipped with a brush and uniformly brushed on the rough titanium substrate surface, and the brushed rough titanium substrate is placed under an infrared lamp for baking for 30 s to remove most of the solvent; and then the brushed rough titanium substrate is placed in a 100°C drying oven for sufficient drying for 10 min to obtain a dry titanium substrate.

[0052] In some embodiments, the first predetermined time is 10 min and the second predetermined time is 60 min.

[0053] In some embodiments, the initial titanium sheet is subjected to electrochemical etching treatment to obtain a rough titanium substrate, including: the initial titanium sheet is cut and then subjected to alkali washing to remove oil to obtain a cut titanium sheet; a double electrode system is formed by using NaBr as an electrolyte, using the cut titanium sheet as a working electrode, and using an initial titanium sheet as a counter electrode; the double electrode system is powered on, first with a constant current of 180 mA·cm -2 The cut titanium sheet is etched once, and then with a constant current of 500 mA·cm -2 The cut titanium sheet is etched twice to obtain the rough titanium substrate.

[0054] In the embodiment, the initial titanium sheet is cut and then subjected to alkali cleaning and oil removal treatment, including: dissolving Na3PO4·12H2O, Na2CO3 and NaOH in deionized water in a mass ratio of 105:25:4 to prepare 0.3% alkali cleaning and oil removal liquid, heating to boiling for standby; after cutting the initial titanium sheet, adding it into the boiling alkali cleaning and oil removal liquid and keeping for a predetermined time; taking out the initial titanium sheet, rinsing it with deionized water and performing ultrasonic cleaning treatment in the deionized water to complete the alkali cleaning process, thereby obtaining the cut titanium sheet.

[0055] The rough titanium substrate obtained by electrochemical etching has higher electrocatalytic activity and electrochemical active area under the same active oxide load; through the electrolysis life strengthening experiment and the electrode failure map, it is speculated that appropriate etching directly affects the service life of the electrode, and the larger hilly undulation and higher roughness of the EE electrode surface can maintain a longer electrolysis life, which shows that electrochemical etching is more conducive to the adhesion of the coating and the stability of the electrode.

[0056] In some embodiments, a copper electrodeposition coated titanium anode is also provided, which is prepared by the preparation method of the copper electrodeposition coated titanium anode.

[0057] In some embodiments, the application of the copper electrodeposition coated titanium anode is also provided, wherein the copper electrodeposition coated titanium anode is used for electrolytic copper.

[0058] Specifically, the electroplating copper electrolyte mainly includes a basic plating solution and an additive, the basic plating solution is generally composed of copper sulfate and sulfuric acid, and the additive mainly includes inorganic additives (Cl - ) and organic additives (leveling agent, accelerator, inhibitor); a high-performance stable anode material needs to be developed for the electroplating environment of strong acid; the power efficiency in the process of electroplating copper is very low, generally difficult to exceed 40%, and the application of the copper electrodeposition coated titanium anode can improve the power efficiency and performance of electroplating copper.

[0059] The application will be further explained and described through specific embodiments as follows:

[0060] Embodiment 1

[0061] A preparation method of a copper electrodeposition coated titanium anode includes the following steps:

[0062] Rough titanium substrate: electrochemical etching uses 1 mol·L -1 NaBr as the electrolyte, and the power supply uses an Enzhi N8352D direct current power supply; the cut titanium sheet is used as the working electrode, a large-area titanium sheet is used as the counter electrode to form a two-electrode system, and the magnetic stirring speed is 800 rpm; the constant current is 180 mA·cm -2 After a period of time, 500 mA·cm-2 After etching for a period of time, two-stage electro-etching is completed; flocculent impurities on the surface are removed by using an ultrasonic cleaning machine, and then the surface is cleaned for 1-2 min by using an acid etching solution (1% HF+10% HNO3), washed for 3-4 times by using deionized water, and finally washed once by using ethanol. The cleaned rough titanium substrate is stored in anhydrous ethanol and used as needed.

[0063] Copper electrodeposition coating titanium anode: the tantalum source of the coating solution is an ethanol tantalum solution, the iridium source is H2IrCl6·6H2O, the strontium source is strontium nitrate, and the solvent is n-butanol. The coating solution is prepared according to a certain proportion of Ir:Ta: Sr = (70-x):30:x (mol%) and is ready for use after 60 min of ultrasonic dispersion; the above-mentioned particle-free coating solution and the titanium substrate prepared by electrochemical etching are used to prepare an iridium tantalum strontium ternary oxide copper electrodeposition coating titanium anode. First, the roughened titanium substrate is taken out from anhydrous ethanol, and the residual anhydrous ethanol on the surface is dried. The coating solution is dipped with a brush and uniformly brushed on the surface of the titanium substrate. The brushed titanium sheet is immediately placed under an infrared lamp for 30 s to remove most of the solvent, and then it is placed in a 100℃ drying oven for full drying for 10 min. The dried titanium sheet is transferred to a muffle furnace, and the temperature is set to rise at a rate of 10℃·min -1 The temperature is raised to 500℃, and the temperature is kept at this temperature for 10 min to complete the coating of the coating solution. The coating work is repeated several times until the coating solution is exhausted. The titanium sheet coated for the last time is placed in a muffle furnace, and the temperature is set to rise at a rate of 10℃·min

[0064] Table 1 Naming of iridium tantalum strontium oxide copper electrodeposition coating titanium anodes with different metal molar ratios

[0065]

[0066]

[0067] The copper electrodeposition coating titanium anode prepared in this embodiment is tested for performance.

[0068] 1. Phase and micro-morphology:

[0069] By adjusting the ratio of the coating solution, the IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anode with different metal molar ratio of coating solution was prepared. By comparing their electrochemical properties and strengthening the electrolytic life, we try to explore the most suitable amount of the third group element strontium. First of all, we study the influence of different metal molar ratio of ternary oxide anode on the micro-morphology of the coating by SEM, Figure 2 In Fig. a, b, c, d are the surface morphology of the anode with 0%, 5%, 10%, 15% (mol%) of strontium added, respectively. From the figure, we can see that when no strontium is added, the surface coating of the binary IrO2-Ta2O5 copper electrodeposition coating titanium anode has larger cracks and is continuous deep cracks. This morphology is the typical surface morphology of the iridium tantalum oxide copper electrodeposition coating titanium anode. With the increase of the metal strontium in the coating solution ratio, Figure 2 In Fig. b-d, the surface oxide film crack depth is reduced and finer. And when the molar ratio of strontium is 10%, it can be seen that the crack depth is significantly reduced, while retaining the existence of many cracks, which will help to improve the actual surface area of the electrode and provide more active sites. In the anode with 15% molar ratio of strontium, the deeper and larger cracks almost disappear, and the cracks are discontinuous small gaps, and the coating is relatively flat.

[0070] From the SEM figure above, we can find that the addition of metal element strontium can have a significant impact on the morphology of the active layer, and when the addition of strontium is 10%, we can prepare a more ideal micro-morphology. In order to explore the composition of the prepared iridium tantalum strontium oxide copper electrodeposition coating titanium anode, EDS was used to analyze the elements on the surface of the titanium anode. Figure 3 EDS of the iridium tantalum strontium oxide copper electrodeposition coating titanium anode with 10% molar ratio of strontium, Figure 3 In Fig. b-e, the element distribution diagram is shown. It can be found that all elements of Sr, Ir, Ta, O are uniformly distributed on the coating. Further, the surface roughness test was conducted to test the surface roughness of the titanium anode, and the influence of the change of the metal ratio of the coating on the roughness was studied. In Table 2, the surface roughness of the substrate and the coating of the iridium tantalum strontium oxide anode with different metal molar ratio is shown.

[0071] Table 2 Surface roughness of the iridium tantalum strontium oxide copper electrodeposition coating titanium anode with different metal molar ratio

[0072]

[0073] From Table 2, it can be seen that the roughness decreases after coating, because during the coating process, the coating solution is more likely to accumulate in the lower pits, thereby reducing the roughness value. The roughness value of the anode with 10% and 15% strontium content changes greatly before and after coating. Combined with the SEM image, it can be seen that the morphology of Sr10 / Ir60 also changes compared with Sr0 / Ir70 and Sr5 / Ir65, thereby causing a large change in roughness before and after coating. This will also affect the oxygen evolution activity of the copper electrodeposited coating titanium anode.

[0074] The phase composition of the iridium tantalum strontium oxide copper electrodeposited coating titanium anode prepared in this chapter was detected by XRD. Figure 4 The XRD patterns of iridium tantalum strontium oxide copper electrodeposited coating titanium anodes with different metal molar ratios. Since the thickness of the metal oxide coating is about 5 μm, and the XRD test depth is generally more than 10 μm, it can completely penetrate the coating to reach the titanium substrate, so there are clear titanium diffraction peaks in the XRD pattern. Compared with the JCPDS card, it can be found that in addition to the titanium substrate peak, there are IrO2 diffraction peaks at 27.5°, 34.6° and 53.6° in the XRD pattern. After analysis and literature review, it can be known that IrO2 is rutile type. There is no characteristic peak of Ta2O5 in the XRD pattern, which is preliminarily judged that under the sintering temperature of 500°C, Ta exists in amorphous state in the coating prepared, and β-Ta2O5 is not generated, so there is no diffraction peak information in the XRD pattern.

[0075] 2. Polarization curve:

[0076] The OER performance and stability of the titanium anode were tested to explore its potential for use in the electrolytic copper foil industry. Figure 5 The LSV activity curve of the IrO2-Ta2O5-SrO2 copper electrodeposited coating titanium anode, at a certain potential, the oxygen evolution current density can reflect the electrocatalytic activity of different metal oxide coatings. Figure 5The trend of the activity curve of different strontium addition amounts in a is basically consistent, which shows that similar anodic reactions occur. However, in the potential range of 1.4 V to 2 V, the Sr10 / Ir60 electrode has the highest current density, and the current density of the Sr15 / Ir55 electrode is relatively the lowest in this range. In the potential range of 1.4 V to 1.65 V, the oxygen evolution activities of the Sr0 / Ir70 and Sr5 / Ir65 electrodes are similar, and the current density of the Sr0 / Ir70 electrode is higher than that of the Sr5 / Ir65 electrode at a potential higher than 1.65 V. In summary, when the strontium addition amount is 10% of the total metal amount, the amount of iridium can be reduced, and the catalytic activity of the ternary copper electrodeposited coating titanium anode is higher than that of the iridium-tantalum binary copper electrodeposited coating titanium anode without strontium. When the proportion of iridium metal is further reduced and the proportion of strontium is increased, the current density of the Sr15 / Ir55 electrode decreases again. Based on the graph, it can be concluded that when the strontium addition amount is 10%, the Sr10 / Ir60 electrode has the highest oxygen evolution activity in the higher potential range of 1.4 V to 2.0 V.

[0077] Figure 5 In b, the Tafel slope curve is obtained by linear fitting, and the Tafel slope is positively correlated with the difficulty of oxygen absorption of the electrode. The larger the Tafel slope, the slower the electron transfer during the reaction, and the poorer the catalytic activity. The Tafel slopes of the Sr5 / Ir65 and Sr10 / Ir60 electrodes prepared into ternary oxide coating anodes are smaller than that of the Sr0 / Ir70 electrode, and the slope of the Tafel curve decreases, indicating that the oxygen evolution overpotential of the anode increases slowly with the increase of the current density, indicating that the Sr10 / Ir60 coating has good electrocatalytic activity. However, the Tafel slope of the Sr15 / Ir55 electrode is the largest, indicating that the catalytic activity of the Sr15 / Ir55 electrode is the worst. Figure 5 The oxygen evolution activity reflected in the Tafel curve of b is Sr10 / Ir60 > Sr5 / Ir65 > Sr0 / Ir70 > Sr15 / Ir55, which is consistent with the trend of the LSV curve in a. Figure 5 The Tafel slope in a is consistent with the trend of the LSV curve, and it is more intuitive to distinguish by the slope value. The Tafel slope of the Sr10 / Ir60 electrode with a strontium addition amount of 10% is the lowest, and the electrode has the highest electrocatalytic activity.

[0078] 3. Cyclic voltammetry curve

[0079] The cyclic voltammetry curve can reflect the catalytic activity of the coating anode to some extent, but mainly reflects the number of catalytic active sites and the size of the voltammetry of the titanium anode. As shown in a, with the increase of the strontium addition amount, the area covered by the cyclic voltammetry shows an upward trend, which also explains that the activity of the copper electrodeposited coating titanium anode can be higher than that of the ordinary iridium-tantalum copper electrodeposited coating titanium anode after the introduction of the third component strontium. Figure 6 Figure 6 ​The voltammetric charge of each sample is calculated according to the cyclic voltammetry curve integration, and the voltammetric charge Q can obtain more convincing active area size from the electrochemical point of view. The Q value increases with the increase of the molar proportion of strontium, and the molar proportion of strontium between Sr0 / Ir70 and Sr5 / Ir65 increases by 5%, and the voltammetric charge between the two electrodes increases by the largest (74.8%), which shows that the introduction of the third component strontium in the iridium-tantalum binary oxide copper electrodeposited coating titanium anode can be beneficial to the increase of the surface active site and the improvement of the catalytic activity. The addition of the third component strontium is beneficial to the increase of the surface active site of the iridium-tantalum copper electrodeposited coating titanium anode, and is beneficial to the improvement of the electrode catalytic activity.

[0080] 4, Chronoamperometry

[0081] Chronoamperometry is used to continuously record the current density value at a constant potential, so as to explore the electrochemical stability of the iridium-tantalum-strontium oxide copper electrodeposited coating titanium anode with different metal molar ratios. Figure 7 The chronoamperometry curve of the iridium-tantalum-strontium oxide copper electrodeposited coating titanium anode with different metal molar ratios can be seen from the figure that the decay trend of each titanium anode is basically the same, and the rapid decline of the current density is concentrated in 0-150s, and after 300s of decay, it tends to be stable. The chronoamperometry curve of the Sr0 / Ir70 and Sr05 / Ir65 samples fluctuates slightly after 700s, which is mainly due to the fact that a large amount of oxygen bubbles is not discharged in time during the test, which hinders the active site and forms a "bubble shielding effect", so that the current density fluctuates by 2.3mA·cm -2 around 1.4V. The similar chronoamperometry curve shows that the iridium-tantalum-strontium coating with different metal molar ratios has little effect on the 1800s chronoamperometry stability of the electrode.

[0082] 5, Electrochemical impedance spectroscopy

[0083] Electrochemical impedance spectroscopy can reflect the electron transfer rate of the iridium-tantalum-strontium oxide copper electrodeposited coating titanium anode with different metal molar ratios. Figure 8 a is the precursor solution with different metal molar mass ratios, and the iridium-tantalum-strontium copper electrodeposited coating titanium anode prepared in the precursor solution is measured at 1.35V in 0.5mol·L -1 H2SO4solution, and 4.7b is the impedance fitting diagram of the Sr10 / Ir60 sample. We can further understand the electrocatalytic performance of the titanium anode from the impedance diagram, and the Nyquist diagram of all electrodes is a semicircular capacitive arc, and the radius of the arc is positively correlated with the OER reaction charge transfer resistance. The equivalent circuit diagram used for fitting is as follows: Figure 8The equivalent circuit is shown in the middle of Figure 8, and it can be seen from the EIS fitting graph that the experimental data of the Sr10 / Ir60 electrode can be well fitted with the experimental data when using this equivalent circuit, and the fitting result is very good.

[0084] Table 3 is the fitting result of the electrochemical impedance spectroscopy of the titanium substrate with different pretreatment methods

[0085] Sample [R s / Ω·cm 2 ]]> [R ct / Ω·cm 2 ]]> Q dl / mF·cm 2 ]]> nl Sr0 / Ir70 1.914 1.944 105.3 0.8348 Sr5 / Ir65 1.939 1.405 90.9 0.8551 Sr10 / Ir60 2.144 1.070 105.0 0.8370 Sr15 / Ir55 1.911 0.987 109.61 0.8292

[0086] It can be seen from Table 3 that Q dl The data is related to the number of active sites on the coating surface, and the Q dl of the Sr15 / Ir55 sample is the highest, indicating that the coating contains more surface active sites and has better catalytic activity. R ct reflects the resistance value of the oxide coating, and the lower the value, the more conducive to the anode reaction. Among them, the R ct value of Sr10 / Ir60 is the lowest, which is conducive to the electrochemical reaction, and the addition amount continues to increase to 15%, and the R ct value of Sr15 / Ir55 starts to rise again, so the coating resistance value is the lowest when the addition amount is 10%. At the same time, the Q dl value of Sr10 / Ir60 is 105 mF·cm 2 , which is higher than that of Sr0 / Ir70 and Sr5 / Ir65. In summary, when the molar ratio of strontium is 10%, it is more conducive to the OER reaction and has the highest catalytic activity.

[0087] 6. Strengthening electrolysis life test and failure analysis

[0088] The strengthening electrolysis life fold line graph can reflect the change trend of the cell voltage of the iridium tantalum strontium oxide copper electrode coating titanium anode with different metal molar ratios, so as to analyze the failure process of the electrode. According to Figure 9 the fold line change law, when the iridium content is the highest and no strontium is added, the cell voltage and time fold line graph of the Sr0 / Ir70 electrode has a wider flat area than other electrodes. The cell voltage of the Sr5 / Ir65 and Sr10 / Ir60 electrodes rises suddenly and fails soon after the cell voltage rises to 7V, and the cell voltage of the Sr15 / Ir55 electrode rises suddenly at 6.5V. The strengthening electrolysis life of the Sr15 / Ir55 electrode is only 176h. From Figure 10As can be seen from the above table, with the decrease of iridium content in the anode, the reinforced electrolytic life of the titanium anode is decreasing, and the life length is Sr0 / Ir70>Sr5 / Ir65>Sr10 / Ir60>Sr15 / Ir55. A large number of studies have shown that the life of iridium tantalum titanium anode is related to the amount of iridium metal in the coating, that is, the greater the coating amount of iridium metal within a certain range, the longer the reinforced electrolytic life. In combination with the stability test in the electrochemical test, the chronopotentiogram, although the four samples do not exhibit significant differences in electrochemical stability within 1800s of the chronopotentiogram, the electrolytic life decreases with the increase of the amount of strontium added. It shows that in the harsh strong current acid system, the addition of strontium and the decrease of the amount of noble metal iridium will affect the life of the iridium tantalum strontium ternary oxide copper electrodeposition coating titanium anode, and the Sr15 / Ir55 reinforced electrolytic life decreases greatly (48.2%), which is only half of the life of the sample without strontium Sr0 / Ir70.

[0089] The surface micro-morphology analysis of the failed titanium anode can be used to infer its failure behavior. Figure 11 The failure morphology of the iridium tantalum strontium oxide copper electrodeposition coating titanium anode with different metal molar ratios is shown in FIG. 1, wherein a is the failure graph of Sr0 / Ir70 electrode, b is the failure graph of Sr5 / Ir65 electrode, c is the failure graph of Sr10 / Ir60 electrode, and d is the failure graph of Sr15 / Ir55 electrode. According to the failure graph, it can be inferred that the failure process of Sr0 / Ir70 and Sr5 / Ir65 electrodes is that a large amount of dissolution at the coating crack leads to crack deepening. The Sr10 / Ir60 electrode coating falls off seriously, and its shallow crack does not appear obvious deepening. When the amount of strontium added increases to 15%, the failure graph of Sr15 / Ir55 electrode is obviously different from the failure graphs of the previous three electrolyses, and a large amount of coating fall-off does not appear on the failure graph. According to the failure SEM graph, it can be inferred that the coating fall-off and crack deepening will lead to the corrosion of the titanium substrate by the electrolyte intruded into the titanium substrate, and finally lead to the failure of the electrode.

[0090] 7. Electrolytic copper foil

[0091] The size of the IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anode with a platinum interlayer of 10mmx15mmx0.5mm is enlarged for the practical application of electrolytic copper foil. Under the same preparation conditions, a coated titanium electrode with a size of 40mmx30mmx0.5mm is prepared. The self-made titanium electrode is used as an anode, and a purchased polished pure titanium plate is used as a cathode. Before use, the pure titanium cathode is activated in a mixed solution of 5% hydrogen peroxide and 10% sulfuric acid for 5 minutes. Then the cathode plate and the anode plate are placed in an electrolytic cell, and the distance between the two plates is controlled to be 1cm.

[0092] Related tests of copper foil: Figure 12The micro-morphology of the electrolytic copper foil is shown, wherein a is the bonding surface of the pure titanium cathode, which is usually called light surface, and the scratch-like micro-surface is due to the transfer printing of the scratch on the surface of the pure titanium cathode, and the macroscopic surface is generally bright and smooth. b is the surface of the grain growth in the solution, which is usually called rough surface, and the surface is composed of uniform copper convex crystals. The average roughness of the a light surface is 0.071 μm, and the Rz is 0.510 μm; the Ra of the b rough surface is 0.577 μm, and the Rz is 3.098 μm. Figure 13 The tensile test of the self-made copper foil is shown, the test sample is bone-shaped, the width is 0.2 cm, the thickness is 31.3 μm and 29.4 μm. Figure 13 As can be seen in the table, the tensile strength reaches 303 MPa and 286 MPa.

[0093] In conclusion, by introducing metal strontium into the coating liquid, the use amount of the noble metal iridium is reduced in the same proportion, the IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anode is prepared, and the electrochemical performance of the titanium anode with the proportions of Ir: Sr = 70: 0, Ir: Sr = 65: 5, Ir: Sr = 60: 10, Ir: Sr = 55: 15 (mol%) is compared, and the phase morphology analysis is compared. The following conclusions are drawn: according to the comparison of the electrochemical performance test, when the strontium addition amount is 5%, the electrochemical performance is similar to that when the strontium addition amount is 0%, and the IrO2-Ta2O5-SrO2 copper electrodeposition coating titanium anode with the strontium addition amount of 10% can obtain better catalytic activity than the IrO2-Ta2O5 copper electrodeposition coating titanium anode. According to the SEM graph and the electrochemical test, it can be inferred that the addition of strontium is beneficial to the increase of the active sites on the surface of the copper electrodeposition coating titanium anode, the real area of the copper electrodeposition coating titanium anode is increased, and the electro-catalytic activity of the copper electrodeposition coating titanium anode is improved.

[0094] It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes according to the above description, and all these improvements and changes shall belong to the protection scope of the appended claims of the present application.

Claims

1. A method for preparing a copper electrodeposited coated titanium anode, characterized in that, Including the following steps: The initial titanium sheet was etched to obtain a rough titanium substrate. An iridium source compound, a tantalum source compound, and a strontium source compound were added to an organic alcohol in a molar percentage ratio of Ir:Ta:Sr = (70-x):30:x, and the mixture was ultrasonically dispersed to obtain a coating solution, wherein 10 ≤ x ≤ 15. The coating liquid is uniformly brushed onto the surface of the rough titanium substrate and then baked to obtain a dry titanium substrate. The dried titanium substrate is transferred to a muffle furnace and heated to 400-600°C in air atmosphere for a first predetermined time to complete the coating process. After repeated coating, the titanium substrate with the last coating is placed in a muffle furnace and heated to 400-600℃ in an air atmosphere for a second predetermined time to obtain a copper electrodeposited titanium anode with a surface coating of IrO2-Ta2O5-SrO2.

2. The method for preparing a copper electrodeposited coated titanium anode according to claim 1, characterized in that, The iridium source compound is H2IrCl6·6H2O, the tantalum source compound is tantalum ethoxide, the strontium source compound is strontium acetate, and the organic alcohol is one or more of n-butanol, ethanol, and propanol.

3. The method for preparing a copper electrodeposited coated titanium anode according to claim 1, characterized in that, After uniformly brushing the coating liquid onto the rough titanium substrate surface, a baking process is performed, including: The coating liquid was applied evenly to the surface of the rough titanium substrate by brushing it with a brush. The rough titanium substrate after brushing was then baked under an infrared lamp for 30 seconds to remove most of the solvent. The rough titanium substrate after brushing is then placed in a 100℃ drying oven and dried for 10 minutes to obtain a dried titanium substrate.

4. The method for preparing a copper electrodeposited coated titanium anode according to claim 1, characterized in that, The first predetermined time is 10 minutes, and the second predetermined time is 60 minutes.

5. The method for preparing a copper electrodeposited coated titanium anode according to claim 1, characterized in that, The initial titanium sheet is etched to obtain a rough titanium substrate, including: The initial titanium sheet is cut and then subjected to alkaline washing and degreasing treatment to obtain the cut titanium sheet; Using NaBr as the electrolyte, the cut titanium sheet as the working electrode, and the initial titanium sheet as the counter electrode, a dual-electrode system is constructed. The dual-electrode system is energized, initially with a constant current of 180 mA·cm⁻¹. -2 The cut titanium sheet is etched once, and then subjected to a constant current of 500 mA·cm. -2 The cut titanium sheet is etched a second time to obtain the rough titanium substrate.

6. The method for preparing a copper electrodeposited coated titanium anode according to claim 5, characterized in that, The initial titanium sheet is cut and then subjected to alkaline washing and degreasing treatment, including: Dissolve Na3PO4·12H2O, Na2CO3, and NaOH in deionized water at a mass ratio of 105:25:4 to prepare a 0.3% alkaline washing and degreasing solution, and heat it to boiling for later use. After the initial titanium sheet is cut, it is added to the boiling alkaline degreasing solution and kept for a predetermined time. After the initial titanium sheet is removed, it is rinsed with deionized water and then ultrasonically cleaned in deionized water to complete the alkaline washing process, thus obtaining the cut titanium sheet.

7. A copper electrodeposited titanium anode, characterized in that, The titanium anode with copper electrodeposition coating as described in any one of claims 1-6 was prepared.

8. An application of a copper electrodeposited coating on a titanium anode, characterized in that, The copper electrodeposited titanium anode of claim 7 is used for electrolytic copper.

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