Electrolyte for preparing metal rubidium through low-temperature electrodeposition and preparation method of metal rubidium

Abstract

The invention discloses an electrolyte for preparing metal rubidium through low-temperature electrodeposition and a preparation method of the metal rubidium, and belongs to the technical field of preparation of alkali metal rubidium. The electrolyte is composed of an aprotic strong polar solvent triethyl phosphate and anhydrous rubidium chloride or anhydrous rubidium nitrate, and the molar concentration of rubidium chloride or rubidium nitrate in the electrolyte is 0.1-1.5 mol / L; the preparation method comprises the following steps: adding electrolyte into an electrolytic bath, setting an anode as a high-purity graphite plate, setting a cathode as a high-purity tin plate or a high-purity copper plate or a high-purity aluminum plate, setting constant-potential electrolytic voltage as-3 to-4.5 V vs Ag, electrifying and electrolyzing at-10 to 25 DEG C for at least 45 minutes, depositing metal rubidium on the cathode plate, and sealing the deposited metal rubidium with argon or packaging the deposited metal rubidium with paraffin oil. According to the method, the metal rubidium can be prepared through electro-deposition at the low temperature by means of an electrolyte system composed of rubidium chloride or rubidium nitrate and triethyl phosphate, the technological process is simple and short, energy consumption is low, the product purity is high, and the purity of the metal rubidium is 99.9% or above.

Description

Technical Field

[0001] The present invention relates to the technical field of alkali metal rubidium preparation, and in particular to an electrolyte for preparing metal rubidium by low-temperature electrodeposition and a method for preparing metal rubidium. Background Art

[0002] Rubidium metal is an alkali metal element with important applications. Its abundance in the Earth's crust is approximately 90 ppm (parts per million), comparable to metals like nickel and zinc, but far lower than common alkali metals like sodium and potassium. Rubidium and its compounds have a wide range of applications in numerous fields. For example, in atomic clocks, metallic rubidium is heated and evaporated to form rubidium atomic vapor. These rubidium atoms interact with microwave fields to produce a stable high-frequency oscillation signal with an accuracy of less than one second per million years. Therefore, rubidium atomic clocks, with their ultra-high time accuracy, play a key role in satellite navigation, communication networks, and scientific research. In electronics, metallic rubidium can be used to manufacture optoelectronic devices such as phototubes and photovoltaic cells. Rubidium atoms' outer electrons are easily excited, generating a photoelectric effect under the influence of light, converting light energy into electricity. In the energy sector, rubidium vapor is used as the working medium in thermionic power generation systems. Rubidium metal also has extensive applications in fuel cells, medicine, chemical catalysts, and specialty glass and ceramics.

[0003] At present, the main methods for preparing metallic rubidium include high-temperature electrolysis, thermal reduction, and room-temperature electrolysis. Among them, the high-temperature electrolysis method is to heat a rubidium compound (such as rubidium chloride) to a molten state (600-650°C) for electrolysis. This process requires a large amount of electricity and places extremely high demands on the high-temperature and corrosion resistance of the equipment (high-temperature alkali metal vapor is extremely corrosive). In addition, due to the extremely active chemical properties of metallic rubidium, it is very easy to react with air, moisture, etc. during the high-temperature electrolysis process, resulting in a complex preparation process and high cost. The thermal reduction method generally uses active metals (such as calcium, magnesium, etc.) to reduce the rubidium compound at high temperature. Although the equipment cost is lower than that of the electrolysis method, the reaction needs to be carried out in a high-temperature environment, which consumes a lot of energy. In addition, the purity of the obtained product is not high, and ultra-pure rubidium (>99.99%) requires multi-stage vacuum distillation purification. The room-temperature electrolysis method is to use ionic liquid to dissolve alkali metal rubidium and directly electrolyze it to prepare metallic rubidium under room temperature conditions. The above-mentioned high-temperature electrolysis method and thermal reduction method for preparing metallic rubidium have problems such as high energy consumption, high cost, complex operation and difficulty in ensuring product purity. The use of ionic liquids to prepare metallic rubidium by room temperature electrolysis can greatly reduce energy consumption. However, ionic liquids have high viscosity, complex synthesis process, many by-products and high cost. The water content in the final ionic liquid product cannot be guaranteed, which seriously affects the process of ionic liquid electrodeposition to prepare active metallic rubidium. In addition, some conventional ionic liquids have a narrow electrochemical window and limited solubility for general chlorides (such as rubidium chloride, etc.). They are also easy to absorb water in the air environment, which greatly limits the practical application of ionic liquids. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides an electrolyte for preparing metallic rubidium by low-temperature electrodeposition and a method for preparing metallic rubidium. The electrolyte system composed of rubidium chloride or rubidium nitrate and triethyl phosphate can realize the electrodeposition preparation of metallic rubidium at low temperature. The process flow is simple and short, and the product purity is high.

[0005] The technical solution adopted in the present invention is:

[0006] In one aspect, the present invention provides an electrolyte for preparing metallic rubidium by low-temperature electrodeposition, which comprises an aprotic strong polar solvent and a rubidium salt solute;

[0007] The aprotic strong polar solvent is triethyl phosphate;

[0008] The rubidium salt solute is anhydrous rubidium chloride or anhydrous rubidium nitrate.

[0009] Furthermore, the molar concentration of rubidium chloride or rubidium nitrate in the electrolyte is 0.1 to 1.5 mol / L.

[0010] On the other hand, the present invention provides a method for preparing metallic rubidium by low-temperature electrodeposition, wherein an electrolyte for preparing metallic rubidium by low-temperature electrodeposition is added to an electrolytic cell, and corresponding anode plates and cathode plates are provided, and then electrolysis is performed at a low temperature to deposit metallic rubidium on the cathode plate.

[0011] Furthermore, during the electrolysis process, the electrolysis temperature is -10 to 25°C.

[0012] Furthermore, during the electrolysis process, the constant potential electrolysis voltage is -3 to -4.5 V vs Ag.

[0013] Furthermore, during the electrolysis process, it is necessary to add anhydrous rubidium chloride or anhydrous rubidium nitrate solid, or add anhydrous rubidium chloride or anhydrous rubidium nitrate triethyl phosphate solution to the electrolytic cell every 10 to 30 minutes to control the molar concentration of rubidium chloride or rubidium nitrate in the electrolyte to be ±3% of the initial concentration.

[0014] Furthermore, during the electrolysis process, the anode is set to be a high-purity graphite plate, and the cathode is set to be a high-purity tin plate or a high-purity copper plate or a high-purity aluminum plate.

[0015] Furthermore, the distance between the anode and the cathode is 10 to 20 mm.

[0016] Furthermore, the deposited metallic rubidium is sealed with argon gas or encapsulated with paraffin oil.

[0017] The beneficial effects of the present invention are:

[0018] (1) The present invention provides an electrolyte for preparing metallic rubidium by low-temperature electrodeposition, namely, a triethyl phosphate solution of rubidium chloride or rubidium nitrate. In the electrolyte system, the triethyl phosphate solvent is a non-proton strong polar solvent with a high dielectric constant and good chemical stability. The solvent not only has excellent solubility for rubidium chloride, but also is not easily electrolyzed during the electrolysis process and will not be consumed or lost. The solvent is also non-corrosive to cathode metals such as indium, tin, and aluminum, and will not affect the performance of the cathode material.

[0019] (2) The present invention utilizes an electrolyte system composed of rubidium chloride or rubidium nitrate and triethyl phosphate to realize the preparation of metallic rubidium by electrodeposition at low temperature. The process is simple and short, and the product purity is high. Compared with the high-temperature molten salt electrolysis method and the reduction method, it can significantly reduce production energy consumption and production costs, and is non-corrosive to equipment. In addition, the triethyl phosphate solvent is non-toxic, has a low melting point, is easy to recycle, has good safety performance, and has a large-scale chemical production background. The solvent cost is also greatly reduced compared to ionic liquids. The method of the present invention provides technical support for the green, low-carbon, and low-cost preparation of metallic rubidium, which is conducive to the realization of large-scale application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 This is a photograph of metallic rubidium prepared by electrodeposition in Example 2 of the present invention and stored in paraffin oil;

[0022] Figure 2 1 is the cyclic voltammetry curve of Example 2 during the electrodeposition process of the present invention;

[0023] Figure 3 This is a scanning electron microscope photograph of the metal rubidium coating prepared by electrodeposition in Example 2 of the present invention. DETAILED DESCRIPTION

[0024] The present invention provides an electrolyte solution and a method for preparing metallic rubidium by low-temperature electrodeposition. To clarify the objectives, technical solutions, and effects of the present invention, the present invention is described in further detail below. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention.

[0025] Unless otherwise specified, the experimental methods described in the following examples of the present invention are conventional methods; the reagents and materials described are all commercially available unless otherwise specified.

[0026] The anhydrous rubidium chloride used in the following embodiments of the present invention has a purity of 99.99%, the anhydrous rubidium nitrate has a purity of 99.99%, and the triethyl phosphate has a purity of 99.99%. The solubility of rubidium chloride and rubidium nitrate in triethyl phosphate can reach 1.5 mol / L.

[0027] In the following embodiments of the present invention, a common AC / DC power source used in a laboratory is used as the power source for electrodeposition.

[0028] The anode of the following embodiment of the present invention is a high-purity graphite plate (purity ≥ 99.99%), and the area of ​​insertion into the electrolyte is 18cm 2 The cathode is a high-purity copper plate, high-purity tin plate or high-purity aluminum plate (purity ≥ 99.99%), and the area inserted into the electrolyte is 9 cm 2 The reference electrode is a silver wire (purity ≥ 99.99%, diameter 4 mm), and the distance between the cathode and the anode is 10 to 20 mm.

[0029] In the following embodiments of the present invention, in order to facilitate the control of the electrolysis temperature, corresponding heating equipment or cooling equipment is also configured, and a temperature control system is configured to use a temperature sensor to monitor the temperature in the electrolytic cell in real time, and automatically adjust the operating power of the heating equipment or cooling equipment based on the temperature feedback from the temperature sensor to maintain a constant temperature in the electrolytic cell.

[0030] In the following examples of the present invention, the content of rubidium element is detected by ICP (inductively coupled plasma atomic emission spectroscopy); the surface morphology of the metal rubidium coating is detected by SEM (scanning electron microscope), and the thickness of the metal rubidium coating is detected by step profiler.

[0031] Example 1

[0032] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0033] (1) preparing an electrolyte: placing anhydrous rubidium chloride as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium chloride to form an electrolyte system, wherein the molar concentration of rubidium chloride in the electrolyte system is 0.1 mol / L; and simultaneously preparing a high-concentration electrolyte with a molar concentration of rubidium chloride of 0.5 mol / L as a supplementary electrolyte;

[0034] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity copper plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 10 mm between the anode and cathode;

[0035] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of 25°C and an electrolysis voltage of -3V (vsAg) for electrolysis. A certain amount of high-concentration electrolyte is added to the electrolytic cell through a peristaltic pump every 10 minutes to replenish the electrolyte. The molar concentration of rubidium chloride in the electrolyte in the electrolytic cell is maintained at about 0.1 mol / L, and the concentration fluctuation is controlled within 3%. After 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0036] Example 2

[0037] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0038] (1) preparing an electrolyte: placing anhydrous rubidium nitrate as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium nitrate to form an electrolyte system, wherein the molar concentration of rubidium nitrate in the electrolyte system is 0.3 mol / L; and simultaneously preparing a high-concentration electrolyte with a molar concentration of rubidium nitrate of 1 mol / L as a supplementary electrolyte;

[0039] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity tin plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 11 mm between the anode and cathode;

[0040] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of 20°C and an electrolysis voltage of -3.3V (vsAg) for electrolysis. A certain amount of high-concentration electrolyte is added to the electrolytic cell through a peristaltic pump every 25 minutes to replenish the electrolyte. The molar concentration of rubidium nitrate in the electrolyte in the electrolytic cell is maintained at about 0.3 mol / L, and the concentration fluctuation is controlled within 3%. After 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0041] Example 3

[0042] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0043] (1) preparing an electrolyte: placing anhydrous rubidium chloride as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium chloride to form an electrolyte system, wherein the molar concentration of rubidium chloride in the electrolyte system is 0.5 mol / L; and simultaneously preparing a high-concentration electrolyte with a molar concentration of rubidium chloride of 1.0 mol / L as a supplementary electrolyte;

[0044] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity aluminum plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 13 mm between the anode and cathode;

[0045] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of 15°C and an electrolysis voltage of -3.5V (vsAg) for electrolysis. A certain amount of high-concentration electrolyte is added to the electrolytic cell through a peristaltic pump every 25 minutes to replenish the electrolyte. The molar concentration of rubidium chloride in the electrolyte in the electrolytic cell is maintained at about 0.5 mol / L, and the concentration fluctuation is controlled within 3%. After 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0046] Example 4

[0047] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0048] (1) preparing an electrolyte: placing anhydrous rubidium nitrate as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium nitrate to form an electrolyte system, wherein the molar concentration of rubidium nitrate in the electrolyte system is 0.7 mol / L; and simultaneously preparing a high-concentration electrolyte with a molar concentration of rubidium nitrate of 1.0 mol / L as a supplementary electrolyte;

[0049] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity copper plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 15 mm between the anode and cathode;

[0050] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of 10°C and an electrolysis voltage of -3.7V (vsAg) for electrolysis. A certain amount of high-concentration electrolyte is added to the electrolytic cell through a peristaltic pump every 25 minutes to replenish the electrolyte. The molar concentration of rubidium nitrate in the electrolyte in the electrolytic cell is maintained at about 0.7 mol / L, and the concentration fluctuation is controlled within 3%. After 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0051] Example 5

[0052] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0053] (1) preparing an electrolyte: placing anhydrous rubidium chloride as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium chloride to form an electrolyte system, wherein the molar concentration of rubidium chloride in the electrolyte system is 0.9 mol / L; and simultaneously preparing a high-concentration electrolyte with a molar concentration of rubidium chloride of 1.5 mol / L as a supplementary electrolyte;

[0054] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity tin plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 17 mm between the anode and cathode;

[0055] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of 5°C and an electrolysis voltage of -3.9V (vsAg) for electrolysis. A certain amount of high-concentration electrolyte is added to the electrolytic cell through a peristaltic pump every 25 minutes to replenish the electrolyte. The molar concentration of rubidium chloride in the electrolyte in the electrolytic cell is maintained at about 0.9 mol / L, and the concentration fluctuation is controlled within 3%. After 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0056] Example 6

[0057] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0058] (1) preparing an electrolyte: placing anhydrous rubidium nitrate as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium nitrate to form an electrolyte system, wherein the molar concentration of rubidium nitrate in the electrolyte system is 1.1 mol / L;

[0059] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity aluminum plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 18 mm between the anode and cathode;

[0060] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of 0°C and an electrolysis voltage of -4.1V (vsAg) for electrolysis. Anhydrous rubidium chloride solid is added to the electrolytic cell every 25 minutes for replenishment and stirring, so that the molar concentration of rubidium nitrate in the electrolyte in the electrolytic cell is maintained at about 1.1 mol / L, and the concentration fluctuation is controlled within 3%; after 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0061] Example 7

[0062] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0063] (1) preparing an electrolyte: placing anhydrous rubidium chloride as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium chloride to form an electrolyte system, wherein the molar concentration of rubidium chloride in the electrolyte system is 1.3 mol / L;

[0064] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity copper plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 19 mm between the anode and cathode;

[0065] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of -5°C and an electrolysis voltage of -4.3V (vsAg) for electrolysis. Anhydrous rubidium chloride solid is added to the electrolytic cell every 25 minutes for replenishment and stirring, so that the molar concentration of rubidium chloride in the electrolyte in the electrolytic cell is maintained at about 1.3 mol / L, and the concentration fluctuation is controlled within 3%; after 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0066] Example 8

[0067] This embodiment uses an electrochemical deposition method to prepare metallic rubidium, and the specific steps are as follows:

[0068] (1) preparing an electrolyte: placing anhydrous rubidium nitrate as a solute and triethyl phosphate as a solvent into a glass electrolytic cell at room temperature, and stirring to dissolve the anhydrous rubidium nitrate to form an electrolyte system, wherein the molar concentration of rubidium nitrate in the electrolyte system is 1.5 mol / L;

[0069] (2) Pretreatment of anode and cathode materials: polish the anode high-purity graphite plate and cathode high-purity tin plate with sandpaper, then ultrasonically clean with acetone, rinse with deionized water, and finally blow dry with nitrogen; insert the pretreated anode and cathode into the electrolytic cell with a distance of 20 mm between the anode and cathode;

[0070] (3) Preparation of metallic rubidium by electrodeposition: The electrolyte system in the electrolytic cell is kept at a constant temperature of -10°C and an electrolysis voltage of -4.5V (vs Ag) for electrolysis. Rubidium nitrate solid is added to the electrolytic cell every 30 minutes for replenishment and stirring, so that the molar concentration of rubidium nitrate in the electrolyte in the electrolytic cell is maintained at about 1.5 mol / L, and the concentration fluctuation is controlled within 3%. After 60 minutes of electrolysis, the metallic rubidium deposited on the surface of the cathode plate is encapsulated with paraffin oil to prevent oxidation and spontaneous combustion.

[0071] Comparative Example 1

[0072] The difference between this comparative example and Example 1 is that in this comparative example, trimethyl phosphate is used as the solvent.

[0073] When trimethyl phosphate is used as the solvent in this comparative example, the solubility of rubidium chloride can reach a maximum of about 1.5 mol / L. However, the electron donation capacity of the methyl group in trimethyl phosphate is weaker than that of the ethyl group, and the stability of the methyl ester bond is also lower than the stability of the ethyl ester bond in triethyl phosphate. During the electrolysis process of this electrolyte system, the trimethyl phosphate solvent has decomposed before metallic rubidium is deposited, indicating that the trimethyl phosphate solvent has poor electrochemical stability. In addition, its boiling point is relatively low and it has certain toxicity, making it unsuitable as a solvent for the electrolyte system.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 1 is that in this comparative example, tributyl phosphate is used as the solvent.

[0076] When tributyl phosphate was used as the solvent in this comparative example, the solubility of rubidium chloride could reach a maximum of about 0.7 mol / L. Moreover, during the electrolysis process of the electrolyte system, the tributyl phosphate solvent decomposed before metallic rubidium was deposited. This indicates that the electrochemical stability of the tributyl phosphate solvent is poor. In addition, tributyl phosphate is toxic and is not suitable as a solvent for the electrolyte system.

[0077] Comparative Example 3

[0078] The difference between this comparative example and Example 1 is that in this comparative example, rubidium carbonate is used as the solute.

[0079] When rubidium carbonate is used as the solute in this comparative example, rubidium carbonate is basically insoluble in triethyl phosphate, and is also basically insoluble in trimethyl phosphate and tributyl phosphate. Therefore, it is impossible to configure an electrolyte system containing rubidium ions. Rubidium carbonate is not suitable as a solute in the electrolyte system.

[0080] The metal rubidium prepared by electrodeposition in Examples 1-8 was subjected to ICP testing (the metal rubidium deposited layer needs to be dissolved in an acid solution to measure the metal ion content), SEM testing, and thickness testing. The test results are shown in Table 1 below.

[0081] Table 1 Related test results of metallic rubidium prepared by electrodeposition in Examples 1-9

[0082]

[0083] From the test results in Table 1, it can be seen that the purity of the metallic rubidium prepared by electrodeposition in the above Examples 1-8 reaches above 99.9%, which is high in purity; the surface of the metallic rubidium coating is smooth and uniform, and the grain size is uniform, the structure is dense, and there are no obvious holes or dendrites.

[0084] In addition, the metal rubidium layer prepared by electrodeposition on the indium cathode plate in the above Example 2 was observed. Figure 1 It can be seen that a layer of metal rubidium is electrodeposited on the tin cathode plate, which appears black-gray under a fluorescent lamp.

[0085] The cyclic voltammetry curve during the electrodeposition process of Example 2 was tested. Figure 2 As shown. Figure 2 Analysis: Since there are only metallic rubidium ions in the electrolyte system, the redox signal in the cyclic voltammetry curve corresponds to the oxidation and reduction process of metallic rubidium. The metallic rubidium ions undergo a reduction reaction at the cathode to release electrons.

[0086] The surface morphology of the metal rubidium prepared by electrodeposition in Example 2 was detected by scanning electron microscopy. Figure 3 As shown. Figure 3 It can be seen that the surface of the metal rubidium coating is smooth, the grain size is uniform, and there are no obvious holes or dendrites.

[0087] It should be noted that the parts not described in the present invention can be implemented by adopting or drawing on existing technologies.

[0088] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. An electrolyte for preparing metallic rubidium by low-temperature electrodeposition, characterized in that: It is composed of aprotic highly polar solvent and rubidium salt solute; The aprotic strong polar solvent is triethyl phosphate; The rubidium salt solute is anhydrous rubidium chloride or anhydrous rubidium nitrate.

2. The electrolyte for preparing metallic rubidium by low-temperature electrodeposition according to claim 1, characterized in that: The molar concentration of rubidium chloride or rubidium nitrate in the electrolyte is 0.1 to 1.5 mol / L.

3. A method for preparing metallic rubidium by low-temperature electrodeposition, characterized in that: The electrolyte as claimed in claim 1 or 2 is added into the electrolytic cell, and corresponding anode plates and cathode plates are arranged, and then electrolysis is carried out at a low temperature to deposit metallic rubidium on the cathode plate.

4. The method for preparing metallic rubidium by low-temperature electrodeposition according to claim 3, characterized in that: During the electrolysis process, the electrolysis temperature is -10 to 25°C.

5. The method for preparing metallic rubidium by low-temperature electrodeposition according to claim 3, characterized in that: During the electrolysis process, the constant potential electrolysis voltage was -3 to -4.5 V vs Ag.

6. The method for preparing metallic rubidium by low-temperature electrodeposition according to claim 3, characterized in that: During the electrolysis process, it is necessary to add anhydrous rubidium chloride or anhydrous rubidium nitrate solid, or anhydrous rubidium chloride or anhydrous rubidium nitrate triethyl phosphate solution to the electrolytic cell every 10 to 30 minutes to control the molar concentration of rubidium chloride or rubidium nitrate in the electrolyte to be ±3% of the initial concentration.

7. The method for preparing metallic rubidium by low-temperature electrodeposition according to claim 3, characterized in that: During the electrolysis process, the anode is set to be a high-purity graphite plate, and the cathode is set to be a high-purity tin plate, a high-purity copper plate, or a high-purity aluminum plate.

8. The method for preparing metallic rubidium by low-temperature electrodeposition according to claim 7, characterized in that: The distance between the anode and the cathode is 10 to 20 mm.

9. A method for preparing metallic rubidium by low-temperature electrodeposition according to any one of claims 3 to 8, characterized in that: The deposited metallic rubidium is sealed with argon gas or encapsulated with paraffin oil.

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