CN106981650B - Preparation method of nanoscale elemental bismuth - Google Patents

Abstract

The invention provides a preparation method of nano-level elemental bismuth. Nano-level elemental bismuth is generated on conductive carbon cloth by an electrochemical deposition method; the electrolyte is bismuth salt, cetyltrimethylammonium bromide and ethylenediamine The mixed aqueous solution of tetraacetic acid sodium salt, wherein the concentration of bismuth salt is (5~30) mmol/L; the concentration of cetyltrimethylammonium bromide is (30~80) mmol/L; The concentration of amine tetraacetic acid sodium salt is (0.1~0.3) mol/L; the electroplating voltage is -1~0V; the electroplating time is 10~90min. The preparation method provided by the invention has low energy consumption, simple and easy to obtain raw materials, simple operation and easy realization, and the prepared elemental bismuth nanomaterial has high specific surface area, excellent electrical conductivity and good energy storage performance, which is the problem of current energy storage. It provides a good anode material and has great application prospects.

Description

A kind of preparation method of nano-scale elemental bismuth

technical field

The invention belongs to the technical field of energy storage material preparation, and more particularly relates to a preparation method of nano-scale elemental bismuth.

Background technique

With the explosive growth of population and the rapid development of society, as one of the cornerstones of social and urgent development, human beings have an increasing demand for energy. However, the existing traditional fossil energy can no longer meet the various energy needs of the future society for a long time. In addition, with the development of fossil energy, the greenhouse effect is becoming more and more serious, the ecological environment is deteriorating, and the problem of uneven distribution of regional energy can be solved. Renewable green energy has become the focus of attention. With the development of social economy and science and technology, the development and utilization of various new energy requires the development of different types of energy storage devices to achieve efficient conversion and utilization of new energy. To realize the in-depth development and efficient utilization of new energy, the development of new efficient and stable electrical energy storage devices is the key.

Traditional ion batteries with organic electrolytes have wide electrochemical windows. However, organic electrolytes are flammable and toxic, and if used improperly, they will bring serious safety and environmental problems. The aqueous electrolyte is environmentally friendly and safe, and its ionic conductivity is two orders of magnitude higher than that of the organic electrolyte, which is expected to achieve high power of the battery, and avoid the strict manufacturing conditions required by the organic electrolyte, which greatly reduces the production cost. Therefore, water-based ion batteries have important application prospects in the field of large-scale energy storage at the grid level. With the deepening of research, researchers have deeply realized that to improve the performance of water-based batteries, the key is to find high-performance energy storage anode materials.

At present, the common negative electrode materials for batteries include carbon negative materials, such as carbon materials that are actually used in lithium-ion batteries. Such materials have low cost and are easy to realize industrialization, but the material capacity is low, and the theoretical capacity of alloy materials and metal oxide materials is relatively high. high, but poor longevity. As an emerging anode material, elemental bismuth has a high anode working potential window and a suitable potential working range, and the theoretical specific capacitance value is high, up to 78.9mAh/g. However, the cycle life of elemental bismuth is relatively poor, and the large-scale preparation method is immature and imperfect. Various conditions restrict the application of elemental bismuth in battery anode materials.

The elemental bismuth materials found so far are mostly used in chemical industry, catalyst, semiconductor, electronic ceramics and so on. Compared with other materials, elemental bismuth is not only rich in resources, low in price, and environmentally friendly, but also has good electrical conductivity and suitable negative potential working range, so it is a high-performance negative electrode material with great development potential. However, there are few studies on elemental bismuth nanomaterials, especially in the field of energy storage, and many reported methods are not suitable for mass production. Therefore, it is of great significance to develop a facile and efficient method for preparing elemental bismuth nanomaterials.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome the existing deficiencies such as providing a kind of preparation method of nano-level elemental bismuth.

The above-mentioned purpose of the present invention is achieved through the following technical solutions:

A preparation method of nano-scale elemental bismuth, wherein nano-scale elemental bismuth is generated on conductive carbon cloth by an electrochemical deposition method; the electrolyte is bismuth salt, cetyltrimethylammonium bromide and ethylenediaminetetraacetic acid sodium salt The mixed aqueous solution, wherein the concentration of bismuth salt is (5~30) mmol/L; the concentration of the cetyltrimethylammonium bromide is (30~80) mmol/L; the sodium EDTA is The salt concentration is (0.1~0.3) mol/L; the electroplating voltage is -1~0V; the electroplating time is 10~90min.

Preferably, the concentration of the bismuth salt in the electrolyte is 20 mmol/L, the concentration of the cetyltrimethylammonium bromide is 50 mmol/L, and the concentration of the sodium EDTA is 0.1 mol/L .

Preferably, the electroplating voltage is -1V, and the electroplating time is 60min.

Preferably, the bismuth salt is bismuth nitrate pentahydrate.

Preferably, the working electrode is a conductive carbon cloth, the counter electrode is a graphite carbon rod, and the reference electrode is a saturated calomel electrode.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The preparation method provided by the invention has low energy consumption, simple and easy to obtain raw materials, simple operation and easy realization, and the prepared elemental bismuth nanomaterial has high specific surface area and excellent electrical conductivity, and compared with mature commercial graphite and other negative electrode materials, the energy storage performance is high. A substantial increase. This invention directly synthesizes elemental bismuth material with high specific surface area on the flexible substrate conductive carbon cloth, and at the same time adopts the electrochemical deposition method, which can be widely used in industrial production, provides a good negative electrode material for the current energy storage problem, and has great application prospect.

Description of drawings

In FIG. 1, (a) is a high-magnification scanning electron microscope (SEM) picture of elemental bismuth in Example 1, and (b) is a low-magnification scanning electron microscope (SEM) picture of elemental bismuth in Example 1.

FIG. 2 is the cyclic voltammetry curve of the elemental bismuth of Example 1 at 100 mV/s.

FIG. 3 is the discharge time of elemental bismuth of Example 1 under different current densities.

FIG. 4 is the XRD of elemental bismuth of Example 1. FIG.

Detailed ways

The present invention will be further described below with reference to specific embodiments and accompanying drawings, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

The synthesis of elemental bismuth on carbon cloth was realized by electrodeposition. Before current loading, carbon cloth (1cm×3cm) was ultrasonically cleaned in deionized water, ethanol, acetone, and deionized water for 10 minutes in sequence, and then dried at 60°C for use. Dip the cleaned carbon cloth into a mixture of 30ml of bismuth nitrate (bismuth nitrate pentahydrate), cetyltrimethylammonium bromide and EDTA sodium salt (sodium EDTA dihydrate). In the three-electrode system of the aqueous solution, 300 mg of nitric acid pentahydrate, 550 mg of hexadecyltrimethylammonium bromide, and 1.12 g of ethylenediaminetetraacetic acid sodium salt. With carbon cloth as the working electrode, graphite carbon electrode as the counter electrode, saturated calomel as the reference electrode, a negative 1V loading voltage was applied to the system, and the reaction was maintained for 60 min. After the reaction, the carbon cloth was taken out, and the obtained sample was washed three times with deionized water and dried at 60°C.

Embodiment 2~5

Based on the scheme of Example 1, the growth of elemental bismuth is affected by regulating different reaction conditions, and the relationship is shown in Table 1.

Table 1

Comparative Example 1: Other conditions were the same as in Example 1, except that the electroplating time was 120 min, and it could be clearly observed that elemental bismuth formed powder agglomeration and did not grow uniformly on the working electrode carbon cloth.

Comparative Example 2: Other conditions were the same as those of Example 1, except that the amount of bismuth nitrate was 800 mg, and it could be clearly observed that elemental bismuth formed agglomeration on the carbon cloth of the working electrode, and could not grow well.

Comparative Example 3: Other conditions were the same as in Example 1, except that the electroplating voltage was 2V. It was obvious that the voltage was relatively high, and large particle powder was obtained, and elemental bismuth could not be deposited well.

Comparative Example 4: Other conditions are the same as in Example 1, except that the amount of cetyltrimethylammonium bromide is 700 mg. It can be clearly observed that elemental bismuth cannot be deposited on the carbon cloth more uniformly, which affects its electrical conductivity. .

From the results in Figures 1 and 4, the elemental bismuth nanomaterials are uniformly grown on the carbon cloth substrate, and Figure 3 shows the discharge time of the elemental bismuth of Example 1 at different current densities. The cyclic voltammetry curves in Figure 2 show that this elemental bismuth nanomaterial has good reversibility and energy storage properties. The area specific capacitance value of this elemental bismuth nanomaterial is calculated to be 356.55mF/cm ² , which shows its good energy storage performance.

Claims (1)

1. a preparation method of nanoscale elemental bismuth, is characterized in that, generates nanoscale elemental bismuth on conductive carbon cloth by electrochemical deposition method; Electrolyte is bismuth salt, hexadecyltrimethylammonium bromide and ethyl acetate. The mixed aqueous solution of diaminetetraacetic acid sodium salt, wherein the concentration of bismuth salt in the electrolyte is 20mmol/L, the concentration of cetyltrimethylammonium bromide is 50mmol/L, and the concentration of ethylenediaminetetraacetic acid sodium salt is 0.1mol/L, the bismuth salt is bismuth nitrate pentahydrate, the working electrode of the electrochemical deposition method is carbon cloth, the counter electrode is a graphite carbon rod, the reference electrode is a saturated calomel electrode, and a negative 1V loading voltage is applied to the system , and keep the reaction for 60min.

Images