Manufacturing method of catalytic electrode assembly for electrochemically preparing ozone water for household appliances

Abstract

The invention relates to a manufacturing method for electrochemically preparing an ozone water catalytic electrode group for household appliances, which comprises the following steps: S1, pretreatment of a pure titanium substrate: after surface sand blasting, soaking the pure titanium substrate in a NaOH solution for 30 minutes, washing the pure titanium substrate, boiling the pure titanium substrate in a 10wt% oxalic acid solution for 2 hours, and ultrasonically washing the pure titanium substrate with deionized water; the problems of catalyst layer falling and dissolution loss are solved, a tin hydroxide passivation layer is formed, and the doped Sb element is selectively separated out. In addition, as the household appliance is compact in structural space and sensitive in cost, compared with application in environment-friendly occasions, the requirement for the performance of the electro-catalysis electrode is higher.

Description

Technical Field

[0001] The invention relates to the field of household appliances, and in particular to a method for manufacturing a catalytic electrode group for electrochemically preparing ozone water for household appliances. Background Art

[0002] In the prior art, when washing clothes in a washing machine, white or light-colored clothes are sometimes contaminated by dyes dropped from the fibers of dark-colored clothes. There is an invention example (authorization announcement number CN 110438733 B) that uses electrolysis to directly generate hydroxyl radicals (·OH) in water to achieve sterilization and disinfection, and decompose free dye molecules to prevent dyes from being contaminated into light-colored clothes and causing color transfer. Hydroxyl radicals (·OH) are a type of active oxygen with extremely strong oxidizing ability and an oxidation potential of 2.8V, but the hydroxyl radicals have a very short lifetime, generally less than 10 -4 s, it is difficult to diffuse and reach a certain concentration, so the effect is limited. The half-life of ozone ranges from a few minutes to tens of minutes, and the half-life in pure water is relatively long, and the half-life in tap water is about 20 minutes (20°C). Diffusion and concentration accumulation are more advantageous, and when necessary, 254nm ultraviolet rays are used to irradiate ozone water, which can decompose ozone and produce hydroxyl radicals. Therefore, ozone decomposes free dye molecules and prevents clothing from color transfer, which is better than the invention example of authorization announcement No. CN 110438733 B.

[0003] The key to directly producing ozone water by electrochemical catalysis lies in the electrocatalytic electrode. Among the existing catalytic electrode materials, antimony-doped tin dioxide (Ti / SnO2-Sb) electrode has the ability to produce ozone and hydroxyl radicals, but it has the problem of low ozone production and short service life. The main reasons for its failure are the shedding and dissolution loss of the catalytic layer, the formation of a tin hydroxide passivation layer, and the selective precipitation of doped Sb elements. In addition, due to the compact structure and space of household appliances and their cost sensitivity, the performance requirements for electrocatalytic electrodes are higher than those for applications in environmental protection occasions. Summary of the invention

[0004] The embodiment of the present application provides a method for manufacturing a catalytic electrode group for electrochemical production of ozone water for household appliances, which solves the problems of catalytic layer shedding and dissolution loss, formation of tin hydroxide passivation layer, and selective precipitation of doped Sb elements in the prior art. In addition, due to the compact structure and cost sensitivity of household appliances, the performance requirements of electrocatalytic electrodes are higher than those of applications in environmental protection occasions.

[0005] The technical solution adopted in the embodiments of the present application is as follows.

[0006] A method for preparing an electrochemical catalytic electrode group for producing ozone water for household appliances, comprising S1: pretreatment of a pure titanium substrate: after sandblasting the surface, soaking it in a NaOH solution for 30 minutes, washing it, boiling it in an oxalic acid solution for 2 hours, and ultrasonically cleaning it with deionized water.

[0007] SnCl4·5H2O, Sb2O3 and H2IrCl6·5H2O were dissolved in a mixture of isopropanol (96 vol%) and concentrated hydrochloric acid (4 vol%) at a molar ratio of 500:8:6 as coating liquid I; SnCl4·5H2O, Sb2O3 and Ni(NO3)2·6H2O were dissolved in a mixture of isopropanol (96 vol%) and concentrated hydrochloric acid (4 vol%) at a molar ratio of 500:8:5 as coating liquid II.

[0008] The coating liquid I is evenly coated on the titanium sheet; dried in a drying oven at 90°C for 10 minutes, then sintered in a muffle furnace at 450°C for 10 minutes, cooled in air, and the above steps are repeated twice to obtain an intermediate layer.

[0009] Use coating liquid II to evenly apply it on the titanium sheet; dry it in a drying oven at 90°C for 10 minutes, then sinter it at 450°C in a muffle furnace for 10 minutes, cool it in air, repeat the above steps for a total of 14 times, and keep it at 550°C for 1 hour for the last time to obtain a Ti / SnO2-Sb-IrO2 / SnO2-Sb-Ni anode containing a SnO2-Sb-IrO2 intermediate layer.

[0010] As a further improvement of the above technical solution: the concentration of the NaOH solution in S1 is 40wt.%; the temperature is 80°C.

[0011] As a further improvement of the above technical solution: the concentration of the oxalic acid solution in S1 is 10wt.%.

[0012] As a further improvement of the above technical solution: the O3 coulombic efficiency first increases and then decreases with the potential of the titanium sheet. When the potential of the titanium sheet is 2.6V (vs Ag / AgCl), the titanium sheet has the optimal O3 production coulombic efficiency of 19%; in addition, as the electrolysis time increases, the amount of ·OH measured in the electrolyte increases linearly, and the amount of ·OH is 0.13mM after 30 minutes of electrolysis; the titanium sheet simultaneously produces two active substances, O3 and ·OH.

[0013] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0014] 1. The anode is first sandblasted on the surface, then immersed in a NaOH solution with a concentration of 40wt.% and a temperature of 80°C for 30 minutes, washed and boiled in a 10wt.% oxalic acid solution for 2 hours, and ultrasonically cleaned with deionized water. The coating liquid I is applied to the anode and placed in a drying oven for drying. At this time, the drying oven is set at 90° and set for 10 minutes. The anode is then placed in a muffle furnace and sintered at 450°C for 10 minutes, cooled in air, and the above steps are repeated twice to obtain an intermediate layer, and the coating liquid II is evenly applied to the titanium sheet; dried at 90°C in a drying oven for 10 minutes, then placed in a muffle furnace and sintered at 450°C for 10 minutes, cooled in air, and the above steps are repeated 14 times. The last time it is kept at 550°C for 1 hour to obtain a Ti / SnO2-Sb-IrO2 / SnO2-Sb-Ni anode containing a SnO2-Sb-IrO2 intermediate layer, thereby achieving a compact structure and enhancing the performance of the anode electrode. DETAILED DESCRIPTION

[0015] The embodiment of the present application provides a method for manufacturing a catalytic electrode group for electrochemical production of ozone water for household appliances, which solves the problems of catalytic layer shedding and dissolution loss, formation of tin hydroxide passivation layer, and selective precipitation of doped Sb elements in the prior art. In addition, due to the compact structure and cost sensitivity of household appliances, the performance requirements of electrocatalytic electrodes are higher than those of applications in environmental protection occasions.

[0016] The technical solution in the embodiment of the present application is to solve the above problems, and the overall idea is as follows

[0017] A method for preparing an electrochemical catalytic electrode group for producing ozone water for household appliances, comprising S1: pretreatment of a pure titanium substrate: after sandblasting the surface, soaking it in a NaOH solution for 30 minutes, washing it, boiling it in an oxalic acid solution for 2 hours, and ultrasonically cleaning it with deionized water.

[0018] SnCl4·5H2O, Sb2O3 and H2IrCl6·5H2O were dissolved in a mixture of isopropanol (96 vol%) and concentrated hydrochloric acid (4 vol%) at a molar ratio of 500:8:6 as coating liquid I; SnCl4·5H2O, Sb2O3 and Ni(NO3)2·6H2O were dissolved in a mixture of isopropanol (96 vol%) and concentrated hydrochloric acid (4 vol%) at a molar ratio of 500:8:5 as coating liquid II.

[0019] The resulting product was dried at 90°C in a drying oven for 10 min, then sintered at 450°C in a muffle furnace for 10 min, and cooled in air. The above steps were repeated twice to obtain an intermediate layer.

[0020] The mixture was dried at 90°C in a drying oven for 10 min, then sintered at 450°C in a muffle furnace for 10 min, cooled in air, and the above steps were repeated 14 times, with the last step being kept at 550°C for 1 h to obtain a Ti / SnO2-Sb-IrO2 / SnO2-Sb-Ni anode 2 containing a SnO2-Sb-IrO2 intermediate layer.

[0021] The concentration of NaOH solution in S1 is 40 wt.%; the temperature is 80°C.

[0022] The concentration of the oxalic acid solution in S1 is 10 wt.%.

[0023] The O3 coulombic efficiency first increased and then decreased as the potential of the titanium sheet increased. When the potential of the titanium sheet was 2.6V (vs Ag / AgCl), the titanium sheet had the optimal O3 coulombic efficiency of 19%. In addition, as the electrolysis time increased, the amount of ·OH measured in the electrolyte increased linearly, and the amount of ·OH was 0.13mM after 30 minutes of electrolysis. The titanium sheet simultaneously produced two active substances, O3 and ·OH.

[0024] The anode is first sandblasted on the surface, then immersed in a NaOH solution with a concentration of 40wt.% and a temperature of 80°C for 30 minutes, washed and boiled in a 10wt.% oxalic acid solution for 2 hours, and ultrasonically cleaned with deionized water. The coating liquid I is applied to the anode and placed in a drying oven for drying. At this time, the drying oven is set at 90° and set for 10 minutes. The anode is then placed in a muffle furnace and sintered at 450°C for 10 minutes, cooled in air, and the above steps are repeated twice to obtain an intermediate layer, and the coating liquid II is evenly applied to the titanium sheet; dried at 90°C in the drying oven for 10 minutes, then placed in a muffle furnace and sintered at 450°C for 10 minutes, cooled in air, and the above steps are repeated 14 times. The last time it is kept warm at 550°C for 1 hour to obtain a Ti / SnO2-Sb-IrO2 / SnO2-Sb-Ni anode containing a SnO2-Sb-IrO2 intermediate layer, thereby achieving a compact structure and enhancing the performance of the anode electrode.

[0025] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0026] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing a catalytic electrode assembly for electrochemical production of ozone water for household appliances, characterized in that: Including S1: pretreatment of pure titanium substrate: after sandblasting, soak it in NaOH solution for 30 minutes, wash it and boil it in oxalic acid solution for 2 hours, and clean it with deionized water ultrasonically. S2. Dissolve SnCl4·5H2O, Sb2O3 and H2IrCl6·5H2O in a mixture of isopropanol (96 vol%) and concentrated hydrochloric acid (4 vol%) at a molar ratio of 500:8:6 as coating liquid I, and then dissolve SnCl4·5H2O, Sb2O3 and Ni(NO3)2·6H2O in a mixture of isopropanol (96 vol%) and concentrated hydrochloric acid (4 vol%) at a molar ratio of 500:8:5 as coating liquid II. S3. Evenly apply coating liquid I on the titanium sheet, dry it in a drying oven at 90° C. for 10 min, then sinter it in a muffle furnace at 450° C. for 10 min, cool it in air, and repeat the above steps twice to obtain an intermediate layer. S4. Then, coating liquid II is used to evenly coat the titanium sheet intermediate layer, dried in a drying oven at 90°C for 10 minutes, and then sintered in a muffle furnace at 450°C for 10 minutes, cooled in air, and the above steps are repeated 14 times, with the last step being kept at 550°C for 1 hour to obtain a Ti / SnO2-Sb-IrO2 / SnO2-Sb-Ni anode (2) containing a SnO2-Sb-IrO2 intermediate layer.

2. The method for manufacturing the electrochemical catalytic electrode assembly for producing ozone water for household appliances according to claim 1, characterized in that: The concentration of NaOH solution in S1 is 40 wt.%; the temperature is 80°C.

3. The method for manufacturing the electrochemical catalytic electrode assembly for producing ozone water for household appliances according to claim 1, characterized in that: The concentration of the oxalic acid solution in S1 is 10 wt.%.

4. The method for manufacturing the electrochemical catalytic electrode assembly for producing ozone water for household appliances according to claim 1, characterized in that: The O3 coulombic efficiency first increased and then decreased as the potential of the titanium sheet increased. When the potential of the titanium sheet was 2.6V (vs Ag / AgCl), the titanium sheet had the optimal O3 coulombic efficiency of 19%. In addition, as the electrolysis time increased, the amount of ·OH measured in the electrolyte increased linearly, and the amount of ·OH was 0.13mM after 30 minutes of electrolysis. The titanium sheet simultaneously produced two active substances, O3 and ·OH.