CN110526350A - A kind of CDI multi-stage porous activated carbon electrodes and its preparation method and application using HAP cracking self-activation - Google Patents

Abstract

The invention belongs to the technical field of desalination of salt-containing solutions, and specifically relates to a method for preparing CDI electrode active materials by cracking and self-activating hydroxyapatite (HAP). Under heat treatment, the HAP is cracked and the carbonized product is self-activated to obtain the CDI electrode material. The invention innovatively utilizes the mechanism that HAP self-cracks at a temperature greater than or equal to 1000°C and simultaneously releases water vapor and CO ₂ to self-activate the carbonized carbon surface to construct a hierarchical porous material in one step. In addition, the present invention also found that the material obtained by using the cracking method of HAP at said temperature has unexpected electrosorption performance in the field of CDI adsorption in salt solution.

Description

A kind of CDI hierarchical porous activated carbon electrode and its preparation method using HAP cracking self-activation law and application

technical field

The invention belongs to the field of electrochemical capacitive deionization, and in particular relates to the preparation of an electrode active material.

Background technique

Due to population growth, industrial development and climate change, scarcity of fresh water resources has become a threatening problem all over the world. To solve this problem, the production of fresh water from seawater and brackish water has attracted extensive attention. Capacitive deionization (CDI) has been widely used in the removal of salt ions in recent years due to its low energy consumption, low cost, energy saving and environmental protection, and easy regeneration.

The desalination performance of capacitive deionization largely depends on the structure and properties of electrode materials. Commercial activated carbons are often used as CDI electrodes due to their high specific surface area and low cost advantages, however, commercial activated carbons are mainly composed of micropores, which exhibit a mismatch between their large specific surface area and the actually usable surface area, thus resulting in low Pore utilization efficiency limits the diffusion and migration of salt ions. Wang et al. (J.Mater.Chem.A, 2016, 4, 10858-10868) used traditional microporous activated carbon as the electrode of CDI, and the measured salt adsorption capacity was only 5.12mg/g, and its average adsorption rate was also relatively low. Low.

So far, various carbon-based materials have been applied in CDI, such as carbon nanotubes, carbon aerogels, mesoporous carbons, carbon fibers, and graphene. However, the above carbon-based materials for CDI are all synthesized by petroleum-derived chemicals, which are non-renewable, will undoubtedly increase the cost of preparation, and are difficult to prepare and apply on a large scale. Activated carbon with a hierarchical porous structure has been widely studied due to its low preparation cost, high electrical conductivity and good electro-adsorption properties. At present, the synthesis of activated carbon with a hierarchical porous structure is mainly divided into the following two methods: one is Through the external template method, the carbon precursor is fully mixed with the external hard template, and after high-temperature carbonization, the external template is dissolved by strong acid to prepare activated carbon with a hierarchical porous structure. Patrick Strubel et al. (Adv. Funct. Mater, 2015, 25, 287-297) used ZnO nanoparticles as an external template to fully mix with sucrose, carbonized at high temperature, and then treated with strong acid to obtain HPCs. Another method is hierarchical porous carbon derived from the cell characteristics of biomass itself, that is, by mixing biomass with chemical activators and carbonizing at high temperature, porous activated carbon is obtained. Yu et al. (ACS Sustainable Chem. Eng, 2018, 6, 15325-15332) first put bagasse in a high-pressure reactor for hydrothermal treatment, and then uniformly mixed the hydrothermal product with KOH and carbonized it in a tube furnace. Finally, it was treated with concentrated hydrochloric acid and dried to obtain hierarchical porous activated carbon. However, the above method for synthesizing hierarchically porous activated carbon needs to add an additional template, which undoubtedly increases the cost of material preparation, is difficult to synthesize on a large scale, and the preparation process is complicated, the use of chemical activators causes pollution, and the use of strong acids Cause problems such as corrosion of equipment.

Contents of the invention

In view of the technical deficiencies in the existing CDI electrode active material preparation methods such as complex preparation process, additional templates need to be added, and the capacitive adsorption performance of the prepared material is not ideal, an object of the present invention is to provide a method for preparing CDI by self-activation of HAP cracking The method of electrode active materials aims to utilize a novel mechanism to prepare electrode materials with excellent performance in CDI adsorption.

The second object of the present invention is to provide a CDI electrode which is added with the CDI electrode active material prepared by self-activation by cracking of HAP.

The third object of the present invention is to provide the preparation method of the CDI electrode and its application in capacitive desalination of saline solution. Aiming at improving the removal of salt ions in salt solution, it promotes the flow of NaCl solution in the electrode, thereby improving the adsorption capacity.

The main purpose of the present invention is to solve the CDI adsorption problem of saline solution, for this reason, the present invention provides a kind of method utilizing hydroxyapatite (HAP) cracking self-activation to prepare CDI electrode active material, will comprise the carbon source of HAP at more than Or heat treatment at a temperature equal to 1000°C to crack the HAP and self-activate the carbonized product to obtain the CDI electrode material.

The main innovations of the present invention are: (1) innovatively utilizing the self-cracking mechanism of hydroxyapatite at a temperature greater than or equal to 1000°C and synchronously releasing water vapor, CO ₂ , and H ₂ to generate self-activation on the surface of carbonized carbon to construct in one step Hierarchical porous materials. (2) The present invention innovatively finds that the material obtained by using the cracking method of HAP at said temperature has unexpected adsorption properties in the field of CDI adsorption in salt solution. Compared with the existing preparation ideas, the present invention provides a new preparation mechanism that does not need to remove the template by acid etching and other methods to create pores, that is, innovatively utilizes the self-cleavage characteristics of hydroxyapatite at a temperature greater than or equal to 1000°C and the mechanism of native activation of the cleavage product. Not only that, the research of the present invention also unexpectedly found that the material prepared by the self-cracking activation method of hydroxyapatite has excellent adsorption performance in CDI adsorption.

Preferably, the carbon source containing HAP is a carbon source containing HAP. The carbon source can be a nitrogen-free carbon source or a nitrogen-containing carbon source. The nitrogen-free carbon source is, for example, sucrose, high-molecular organic matter and the like. The nitrogen-containing carbon source is preferably protein, lipid and the like.

Further preferably, the carbon source containing HAP is a nitrogen-containing carbon source containing HAP.

Preferably, the carbon source containing HAP is animal bone. The animal bones are, for example, bovine bones, pork bones, etc.

Animal bones are washed with water, dried, ground, and screened into 200-mesh particles in advance.

In the present invention, the heat treatment temperature needs to be controlled at 1000° C. or above, so as to ensure sufficient cracking of HAP and self-activation of carbon, thereby unexpectedly significantly improving the adsorption capacity of CDI.

Preferably, the heat treatment temperature is 1000-1200°C.

Preferably, the atmosphere in the heat treatment process is a protective atmosphere; for example, a nitrogen atmosphere, an argon atmosphere.

Preferably, the heating rate is 5-15° C./min.

Preferably, the heat treatment time is 1 to 3 hours.

In the preparation method of the present invention, the HAP is removed by cracking and decomposing, and the pore-forming method does not need to be removed by acid washing.

In the preparation method of the invention, ultrasonic treatment can be performed on the heat-treated product. For example, the heat-treated product obtained is subjected to ultrasonic treatment in a deionized aqueous solution. The ultrasonic time is, for example, 5-15 hours; preferably 5-10 hours.

The CDI electrode active material prepared by the invention has a specific surface area of 884.63-2147.43m ² /g, a nitrogen content of 1.38-5.03%, and an oxygen content of 2.54-10.56%.

The present invention also provides a CDI electrode, which includes a current collector and an electrode material layer compounded on the surface of the current collector; the active material includes a conductive agent, a binder and the active material for the CDI electrode.

Preferably, the current collector is carbon paper, graphite paper, carbon cloth or titanium plate, preferably titanium plate as the current collector.

Preferably, the conductive agent is at least one of acetylene black and conductive carbon black.

Preferably, the binder is at least one of PVDF and PTFE.

Preferably, in the electrode material layer, the content of the conductive agent is 1-10wt.%, and the content of the binder is 1-10wt.%.

The present invention also provides a preparation method of the CDI electrode, wherein the conductive agent, the binder and the CDI electrode active material are slurried with a solvent to obtain a slurry, which is then coated on the surface of the current collector, dried and then have to.

The total mass of electrodes coated on the current collector is about 45-49 mg per electrode.

For example: Dissolve 80 wt% active material, 10 wt% acetylene black and 10 wt% PVDF as a binder in 2 mL of NMP, then sonicate and stir for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C to completely remove NMP. The total mass of electrodes coated on the current collector is about 45 mg per electrode.

The present invention also provides an application of the CDI electrode for capacitive deionization treatment of salt solution.

Compared with prior art, the excellent effect of the present invention is:

1. The present invention innovatively uses the self-cracking mechanism of hydroxyapatite at a temperature greater than or equal to 1000°C and simultaneously releases water vapor and CO ₂ to generate self-activation on the carbonized carbon surface to construct a multi-level porous material in one step; the present invention The hydroxyapatite is fully cracked under the conditions described above, and there is no need to use a template-releasing agent for removal again.

2. The present invention innovatively finds that the material obtained by using the cracking method of HAP at said temperature has unexpected adsorption performance in the field of CDI adsorption in salt solution.

The study found that the CDI electrode has a specific capacitance of 110.5F g ^-1 at a current density of 1Ag ^-1 , and exhibits a capacitance retention rate of 98.7% in 100 continuous charge-discharge cycle tests, when used as a CDI electrode , showed an electrosorption capacity of 19.35 mg g ^-1 at a voltage of 1.2 V in an original solution of 500 mg L ^-1 NaCl solution.

Description of drawings

Figure 1 is the nitrogen adsorption-desorption isotherm and pore size distribution diagram of BC-HPCs-1000 prepared in Example 1; in the figure, BC refers to the bone before treatment, and BC-HPCs-1000 refers to the product after treatment in Example 1.

Fig. 2 is the XRD diffraction pattern and infrared spectrogram of the material before and after the preparation of Example 1; in the figure, BC refers to the bone before treatment, and BC-HPCs-950 refers to the product after the bone is heat-treated at 950 ° C, referring to the treatment of Example 1 product of.

Fig. 3 is the variation curve of the release of gas with temperature in the bone cracking process;

Fig. 4 is the X-ray photoelectron spectrum figure of the BC-HPCs-1000 that embodiment 1 prepares;

Fig. 5 is the cyclic voltammetry curve of the BC-HPCs-1000 electrochemical test prepared in embodiment 1, constant current charge and discharge curve and uninterrupted charge and discharge test figure;

In the above figures, BC indicates the original bone; BC-HPCs-700 indicates that the bone is carbonized to 700°C; BC-HPCs-800 indicates that the bone is carbonized to 800°C; BC-HPCs-900 indicates that the bone is carbonized to 900°C; BC-HPCs-1000 represents bones carbonized to 1000°C, and AC represents purchased commercial activated carbon (Pingdingshan Lvzhiyuan Activated Carbon Co., Ltd., 200-mesh powdered wood activated carbon, specific surface area 1109.03m ² /g).

Detailed ways

In the following, the present invention will be further described in detail in combination with specific embodiments, so as to make the purpose, technical solution and advantages of the present invention clearer. It should be understood that the descriptions presented here are only preferred examples for the purpose of illustration to explain the present invention, and do not constitute a limitation to the present invention. In actual application, those skilled in the art can make improvements and adjustments according to the present invention , still belong to the protection scope of the present invention.

The experimental methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials, unless otherwise specified, can be obtained from commercial sources.

Example 1

The purchased bovine bones (BC) were washed with deionized water at 100°C for 2 hours to remove some residual protein and fat, dried in a vacuum oven at 80°C for 24 hours, and then the dried animal bones were ground into powder, passed Sieve the dried bones into 200-mesh particles with a standard sieve, then take 5g of the sieved bone powder and place it in a quartz tube furnace, heat it to 1000°C at a heating rate of 5°C/min in a nitrogen atmosphere, and keep it at this temperature for 3h , and then the system was naturally cooled to room temperature. The obtained black powder sample was ultrasonically placed in an ultrasonic instrument for 15 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained is BC-HPCs-1000. The specific surface area of BC-HPCs-1000 is 2147.43m ² /g, the nitrogen content is 3.52%, and the oxygen content is 6.35%.

Example 2

The pretreatment of the bone adopts the preparation process of Example 1, then take 5g of the screened bone powder and place it in a quartz tube furnace, heat it to 1000°C at a heating rate of 5°C/min in a nitrogen atmosphere, and keep it at this temperature for 2h , and then the system was naturally cooled to room temperature. The obtained black powder sample was ultrasonically placed in an ultrasonic instrument for 15 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained was designated BC-HPCs-1000-2. BC-HPCs-1000-2 has a specific surface area of 2016.37m ² /g, a nitrogen content of 3.14%, and an oxygen content of 6.27%.

Example 3

The pretreatment of the bone adopts the preparation process of Example 1, then take 5g of the screened bone powder and place it in a quartz tube furnace, heat it to 1000°C at a heating rate of 5°C/min in a nitrogen atmosphere, and keep it at this temperature for 2h , and then the system was naturally cooled to room temperature. The obtained black powder sample was placed in an ultrasonic instrument for 10 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained was designated BC-HPCs-1000-3. BC-HPCs-1000-3 has a specific surface area of 1770.57m ² /g, a nitrogen content of 1.38%, and an oxygen content of 2.54%.

Example 4

The pretreatment of the bone adopts the preparation process of Example 1, then take 5 g of screened bone powder and place it in a quartz tube furnace, heat it to 1200 °C at a heating rate of 5 °C/min in a nitrogen atmosphere, and keep it at this temperature for 3 hours , and then the system was naturally cooled to room temperature. The obtained black powder sample was ultrasonically placed in an ultrasonic instrument for 15 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained was designated as BC-HPCs-1200. The specific surface area of BC-HPCs-1200 is 1935.12m ² /g, the nitrogen content is 0.07%, and the oxygen content is 0.13%.

Comparative example 1

Compared with Example 1, the only difference is that the heat treatment temperature is changed to 700°C, specifically as follows: the pretreatment of the bone adopts the preparation process of Example 1, and then 5 g of screened bone powder is placed in a quartz tube furnace Heated to 700° C. at a heating rate of 5° C./min in a nitrogen atmosphere, kept at this temperature for 2 h, and then cooled the system naturally to room temperature. The obtained black powder sample was placed in an ultrasonic instrument for 10 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained is BC-HPCs-700. The specific surface area of BC-HPCs-700 is 884.63m ² /g, the nitrogen content is 5.03%, and the oxygen content is 10.56%.

Comparative example 2

Compared with Example 1, the only difference is that the temperature of the heat treatment is changed to 800°C, as follows: the pretreatment of the bone adopts the preparation process of Example 1, and then 5 g of screened bone powder is placed in a quartz tube furnace Heated to 800° C. at a heating rate of 5° C./min in a nitrogen atmosphere, kept at this temperature for 2 h, and then cooled the system naturally to room temperature. The obtained black powder sample was placed in an ultrasonic instrument for 10 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained is BC-HPCs-800. The specific surface area of BC-HPCs-800 is 931.46m ² /g, the nitrogen content is 4.86%, and the oxygen content is 10.16%.

Comparative example 3

Compared with Example 1, the only difference is that the heat treatment temperature is changed to 900°C, specifically as follows: the pretreatment of the bone adopts the preparation process of Example 1, and then 5 g of screened bone powder is placed in a quartz tube furnace Heated to 900° C. at a heating rate of 5° C./min in a nitrogen atmosphere, kept at this temperature for 2 h, and then cooled the system naturally to room temperature. The obtained black powder sample was placed in an ultrasonic instrument for 10 h, rinsed with distilled water, and dried at 60 °C for 12 h. The sample thus obtained is BC-HPCs-900. The specific surface area of BC-HPCs-900 is 1123.12m ² /g, the nitrogen content is 4.06%, and the oxygen content is 8.01%.

Comparative example 4

Compared with Example 1, the only difference is that the temperature of heat treatment is changed to 950°C, and ultrasonic treatment is not used, as follows: the pretreatment of bones adopts the preparation process of Example 1, and then 5 g of screened bone powder is placed in a In a quartz tube furnace, heat up to 950° C. at a heating rate of 5° C./min in a nitrogen atmosphere, keep at this temperature for 2 hours, and then cool the system naturally to room temperature. The resulting black powder sample was rinsed with deionized water and dried at 60 °C for 12 hours. The sample thus obtained is BC-HPCs-950. BC-HPCs-950 has a specific surface area of 1311.53m2/g, a nitrogen content of 3.26%, and an oxygen content of 7.54%. And it is found from the XRD diffraction pattern in Figure 2a that the peak of hydroxyapatite still exists, so no cracking of hydroxyapatite occurs at 950°C.

Comparative example 5

The HAP cracking mechanism of the present invention is not used, and the carbonization + acid elution HAP mechanism is adopted,

Compared with Example 1, the only difference is that the temperature of the heat treatment is changed to 800°C, and finally acid treatment is performed, as follows: the pretreatment of the bone adopts the preparation process of Example 1, and then 5 g of the screened bone powder is placed in a In a quartz tube furnace, heat up to 800° C. at a heating rate of 5° C./min in a nitrogen atmosphere, keep at this temperature for 2 hours, and then cool the system naturally to room temperature. The obtained black powder sample was treated with 2mol/L nitric acid for 5h, washed with distilled water until neutral, and dried at 60°C for 12 hours. The sample thus obtained was designated BC-HPCs-800-2. BC-HPCs-800-2 has a specific surface area of 1453.32m2/g, a nitrogen content of 3.96%, and an oxygen content of 10.01%. Obviously, the specific surface area after acid treatment is higher than that of the untreated one, indicating that the undecomposed hydroxyapatite is dissolved by acid at this time, thereby forming a large number of pore structures, resulting in an increase in the specific surface area.

Fig. 1 shows the nitrogen adsorption-desorption and pore size distribution curves of the prepared hierarchical porous carbon materials. Compared with BC, BC-HPCs-1000 shows the type IV nitrogen adsorption-desorption with fast nitrogen adsorption at relatively low pressure, indicating that There are micropores, and obvious hysteresis loops appear under high relative pressure, indicating the existence of mesopores and macropores.

Fig. 2 is the XRD and infrared images of the products treated at different treatment temperatures before treatment.

Figure 2a is the XRD diffraction pattern of the prepared porous activated carbon. When the bone (BC) was not pyrolyzed and at a temperature of 950°C, it showed the diffraction peaks of hydroxyapatite, and after pyrolysis at 1000°C, the hydroxyl The diffraction peak of apatite disappeared, and the 002 diffraction peak unique to carbon materials appeared, indicating that the bone was transformed into carbon and the hydroxyapatite was decomposed. Figure 2b is its infrared spectrum to further illustrate this result. Carbonate groups and phosphate groups still exist in bones at 950°C, showing the presence of hydroxyapatite, but when the temperature is 1000°C, carbonate groups and phosphate groups are carbonized. The clusters disappeared completely, indicating that the hydroxyapatite had decomposed.

To prove the existence of self-activation, Figure 3 shows the mass spectrum of bone during carbonization. When the carbonization temperature is 900 °C, the curves of _H2 and CO rise, indicating that the carbonization process releases hydrogen and carbon monoxide. When the temperature rises to The _CO2 curve drops at 1000°C, indicating that carbon dioxide is consumed and reacts with carbonized carbon, resulting in self-activation, and the following reactions occur:

C+ _H2O →CO+ _H2 (1)

C+CO ₂ →2CO (2)

Application example 1

Electrochemical tests were performed on the porous activated carbon material prepared in Example 3 above. The specific operation process is: mix and dissolve 8 mg of nitrogen and oxygen in-situ co-doped BC-HPCs-1000-3 porous activated carbon prepared in Example 3, 1 mg of conductive carbon black and 1 mg of PVDF as a binder in 1 mL of NMP, and then ultrasonically Treat and stir for 30 minutes to form a uniform slurry, then take 100 μL of the mixed slurry to coat on 1×1 cm ² graphite paper, and dry at 120 °C overnight. The prepared electrode was placed in 1mol/L NaCl electrolyte, the platinum electrode was used as the counter electrode, and silver/silver chloride was used as the reference electrode, and the three-electrode test method was used for electrochemical testing.

Measure its cyclic voltammetry curve (Fig. 5a) under the scan rate of 5-200mV/s according to the porous carbon material that embodiment 3 obtains, and the CV curve under different scan rates of this electrode keeps the similar rectangular shape, even in The rectangular-like shape is still maintained at a scan rate of 200mV/s, indicating that the material has excellent rate capacity. Figure 5b shows the galvanostatic charge-discharge curves of the BC-HPCs-1000-3 electrode at a charge-discharge current density of 0.2-10A/g, further confirming that the material has a good rate capacity. When the current density is 0.2A/g, its specific capacitance is 110.5F/g, which is higher than that of similar materials, which further proves that it has good electrochemical performance. This may be due to the material's high specific surface area and abundant porosity. And when the material was cycled 100 times, it still had a capacitance retention rate of 98.7% (Fig. 4c).

Application example 2

Under the same conditions of Application Example 1, under the current density of 1A/g, the porous carbon materials prepared in Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 were compared and tested for constant current charge and discharge test, and the obtained ratio The capacitances are 50.04, 60.4, 90.7 and 110.5 F/g, respectively, and it is found that BC-HPCs-1000 has the best electrochemical performance.

Application example 3

For the above-mentioned comparative example 1, comparative example 2, the preparation method of the porous carbon material prepared in the comparative example 3 and embodiment 3 by the capacitive deionization electrode provided above: the active material of 80wt%, the acetylene black of 10wt% and 10wt% The PVDF was dissolved in 2 mL of NMP, then sonicated and stirred for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, and a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. As shown in Figure 5a, at an applied voltage of 1.2 V, BC-HPCs-700, BC-HPCs-800, BC-HPCs-900, BC-HPCs-1000-3 and AC The electrosorption capacities of 6.89, 9.42, 12.11, 19.35 and 5.36 mg/g, respectively. Compared with AC, the prepared porous carbon has a high salt adsorption capacity and high salt adsorption rate.

Application example 4

The porous carbon material prepared in the above-mentioned Example 3 was prepared by the above-mentioned capacitive deionization electrode preparation method: 80wt% of BC-HPCs-1000, 10wt% of acetylene black and 10wt% of PVDF were dissolved in 2mL of NMP, Then sonicate and stir for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. The voltage in the CDI device was controlled to be 0.8 V, the flow rate of the NaCl salt solution was 15 mL/min, and the initial concentration of NaCl was 500 mg/L.

Application example 5

For the nitrogen and oxygen in-situ doped porous carbon material prepared in the above Example 3, the preparation method of the capacitive deionization electrode provided above: 80wt% of BC-HPCs-1000, 10wt% of acetylene black and 10wt% of PVDF Dissolve in 2 mL of NMP, then sonicate and stir for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. The voltage in the CDI device was controlled to be 1.0 V, the flow rate of the NaCl salt solution was 15 mL/min, and the initial concentration of NaCl was 500 mg/L.

Application example 6

The nitrogen and oxygen in-situ doped porous carbon material prepared in the above Example 3 is provided by the above preparation method of the capacitive deionization electrode: 80wt% of BC-HPCs-1000-3, 10wt% of acetylene black and 10wt% The PVDF was dissolved in 2 mL of NMP, then sonicated and stirred for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. Control the voltage in the CDI device to be 1.2V, the flow rate of NaCl saline solution to be 15mL/min, and the initial concentration of NaCl to be 500mg/L.

Application example 7

For the nitrogen and oxygen in-situ doped porous carbon material prepared in the above Example 1, the preparation method of the capacitive deionization electrode provided above: 80wt% of BC-HPCs-1000, 10wt% of acetylene black and 10wt% of PVDF Dissolve in 2 mL of NMP, then sonicate and stir for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. The voltage in the CDI device was controlled to be 1.2V, the flow rate of the NaCl salt solution was 15mL/min, and the initial concentration of NaCl was 250mg/L.

Application example 8

For the nitrogen and oxygen in-situ doped porous carbon material prepared in the above Example 1, the preparation method of the capacitive deionization electrode provided above: 80wt% of BC-HPCs-1000, 10wt% of acetylene black and 10wt% of PVDF Dissolve in 2 mL of NMP, then sonicate and stir for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. Control the voltage in the CDI device to be 1.2V, the flow rate of NaCl salt solution to be 15mL/min, and the initial concentration of NaCl to be 1000mg/L.

Application example 9

The nitrogen and oxygen in-situ doped porous carbon material prepared in the above Example 1 was prepared by the preparation method of the capacitive deionization electrode provided above: 80wt% of BC-HPCs-1000, 10wt% of acetylene black and 10wt% of PVDF was dissolved in 2 mL of NMP, then sonicated and stirred for 30 min to form a homogeneous slurry. 1 mL of the mixed slurry was coated on the current collector and dried overnight at 120 °C. The obtained CDI electrodes were assembled into a CDI unit, a certain external voltage was applied between the positive and negative electrodes, and the salt solution to be treated was delivered to the CDI unit through a peristaltic pump, and the capacitive deionization test was performed. Control the voltage in the CDI device to be 1.2V, the flow rate of NaCl saline solution to be 15mL/min, and the initial concentration of NaCl to be 1500mg/L.

Using test conditions similar to Application Example 1, the electrosorption capacity of each embodiment and comparative example was measured. The test conditions and results are shown in Table 1.

Table 1

In summary, the preparation method of the present invention can use HAP cracking to prepare a material with excellent adsorption effect on CDI adsorption.

Claims (10)

1. a kind of method for preparing CDI electrode active material using HAP cracking self-activation, which is characterized in that by the carbon comprising HAP Source more than or equal to 1000 DEG C at a temperature of be heat-treated, crack HAP and to carbonized product self-activation, obtain the CDI Electrode material.

2. the method for preparing CDI electrode active material using HAP cracking self-activation as described in claim 1, which is characterized in that The carbon source comprising HAP is the carbon source comprising HAP, preferably comprising the nitrogenous carbon source of HAP.

3. the method for preparing CDI electrode active material using HAP cracking self-activation as described in claim 1, which is characterized in that The carbon source comprising HAP is animal bone.

4. the method for preparing CDI electrode active material using HAP cracking self-activation as claimed in claim 3, which is characterized in that Animal bone is washed with water in advance, is dried, is ground, screens particle at 200 mesh.

5. the method for preparing CDI electrode active material using HAP cracking self-activation as claimed in claim 3, which is characterized in that The atmosphere of heat treatment process is protective atmosphere；Heating rate is 5~15 DEG C/min；Time is 1~3h.

6. the method for preparing CDI electrode active material using HAP cracking self-activation as described in claim 1, which is characterized in that The heat-treated products of acquisition are ultrasonically treated in deionized water solution.

7. a kind of CDI electrode, which is characterized in that including collector, and be compounded in the electrode material layer of collection liquid surface；It is described Active material include CDI electrode activity material made from any one of conductive agent, binder and claim 1~6 preparation method Material.

8. CDI electrode as claimed in claim 7, which is characterized in that the collector is carbon paper, graphite paper, carbon cloth or titanium Plate；

The conductive agent is at least one of acetylene black, conductive black；

The binder is at least one of PVDF, PTFE；

In electrode material layer, the content of conductive agent is 1~10wt.%；The content of binder is 1~10wt.%.

9. the preparation method of CDI electrode described in a kind of claim 7 or 8, which is characterized in that by the conductive agent, bonding Agent and CDI electrode active material obtain slurry with solvent pulp, are subsequently coated at the surface of collector, are drying to obtain.

10. the application of CDI electrode described in a kind of claim 7 or 8, which is characterized in that the capacitive deionization for salting liquid Processing.