Binary metal oxide composite material as well as preparation method and application thereof

Abstract

The invention discloses a binary metal oxide composite material and a preparation method and application thereof.The preparation method comprises the steps that firstly, MXene dispersion liquid is prepared, then WCl6 is added and fully dissolved, MXene serves as a carrier and a reducing agent to conduct a hydrothermal reaction, then washing and drying are conducted, and an MXene / W18O49 composite material is obtained; and calcining the MXene / W18O49 composite material in an argon atmosphere to obtain the binary metal oxide R-TiO2 / W18O49 composite material, and the composite material can be applied to electrochemical adsorption removal of heavy metal ions in water. The composite material can effectively adsorb and enrich heavy metal ions in a cathode electric field, and compared with an existing composite material and a synthesis means, the preparation method of the composite material can effectively improve the electrochemical polarization degree of active sites, remarkably enhance the heavy metal ion adsorption capacity of the composite material and keep stable application performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of water treatment and specifically relates to a titanium dioxide (R-TiO 2 ) / Tungsten Oxide(W 18 O 49 )Binary metal oxide composite materials and their preparation methods and applications. Background Art

[0002] Capacitive deionization (CDI) is an effective technology for removing inorganic ions from water. It has the characteristics of low voltage, low energy consumption, and environmental friendliness. It is widely used in seawater desalination, heavy metal wastewater treatment and other fields. The electrode materials currently used to build CDI systems include porous carbon materials, ion exchange resins, metal oxides, etc. Among them, metal oxide materials have a strong built-in electric field due to their polar structure, which can remove metal ions through electrostatic adsorption. Studies have found that W 18 O 49 It has abundant surface oxygen defects, surface hydroxyl functional groups and pseudocapacitive properties, which can enhance the adsorption of heavy metal ions, but its poor conductivity limits its electrochemical application performance to a certain extent.

[0003] In order to improve the conductivity of the material, W 18 O 49 Nanoparticles or nanowires are loaded on the surface of highly conductive materials (such as Pd, graphene, etc.) to construct W 18 O 49 The electroactivity of nanoparticle-conductive carrier composites has been improved and has been used in the fields of electrochemical nitrogen fixation and hydrogen production by electrohydrolysis. However, there are still a large number of weakly polarized W particles that are not in contact with the conductive carrier in this type of composite. 18 O 49 Therefore, the charge accumulation of the number of surface active sites is still small, which restricts its effect of electrosorption to remove heavy metal ions. Therefore, it is urgent to further improve the charge accumulation performance of this type of composite material. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention provides a binary metal oxide composite material and a preparation method and application thereof. The present invention adsorbs and reduces the oxide-deficient tungsten precursor WCl by adding MXene exogenously. 6 The two co-grow in a high-temperature argon atmosphere, MXene is converted into rutile titanium dioxide, and WCl 6 Transformed into oxide-deficient tungsten to achieve in-situ synthesis of R-TiO 2 / W 18 O 49 Micro-nano scale mixed composite materials. Different from W 18 O 49The existing composite material composed of nanoparticles and conductive carrier particles, the W of the new material 18 O 49 The active components are dispersed and fixed on rutile titanium dioxide nanosheets, so they have a larger W than traditional composite materials. 18 O 49 The polarization area and the accumulated charge at the active sites show excellent heavy metal removal effects by electrosorption.

[0005] The technical solution of the present invention is:

[0006] The present invention relates to a method for preparing a binary metal oxide composite material, comprising the following steps:

[0007] (1) Prepare MXene dispersion first, then add WCl 6 And fully dissolved, using MXene as a carrier and reducing agent for hydrothermal reaction, and then washed and dried to obtain MXene / W 18 O 49 Composite materials;

[0008] (2) In an argon atmosphere, MXene / W 18 O 49 The composite material is calcined to obtain binary metal oxide R-TiO 2 / W 18 O 49 Composite materials.

[0009] Preferably, the preparation process of Mxene used for preparing Mxene dispersion has the following steps:

[0010] (a) adding LiF to hydrochloric acid and performing ultrasonic vibration to obtain a mixed solution;

[0011] (b) slowly adding a titanium carbide precursor material to the mixed solution obtained in step (a), and reacting in a constant temperature water bath to obtain a MXene suspension;

[0012] (c) centrifuging the MXene suspension obtained in step (b), washing the MXene precipitate with ultrapure water, and then freeze-drying to obtain MXene.

[0013] Preferably, in step (a), the concentration of hydrochloric acid is 5.0-9.0 mol / L, the volume ratio of hydrochloric acid to the mass ratio of LiF is 10-20 mL: 0.5-1.5 g; the ultrasonic frequency of ultrasonic oscillation is 100 Hz, and the time is 30-60 min.

[0014] Preferably, in step (b), the titanium carbide precursor material is 312 type Ti 3 AlC 2, the mass ratio of the titanium carbide precursor material to the mass of LiF is 1 - 1.5: 0.5 - 1.5; the water bath temperature of the constant temperature water bath reaction is controlled at 30 - 40 °C, and the reaction time is 20 - 30 h.

[0015] Preferably, in step (c), the specific process of centrifugation and washing is as follows: centrifuge the black solution at 3500 - 5000 rpm for 5 - 10 min, pour out the waste acid, then add ultrapure water for washing, and centrifuge multiple times until the pH is 5 - 7. Add 20 mL of ultrapure water to the precipitate, centrifuge at 3500 - 5000 rpm for 30 min, pour out the grayish-black supernatant, scrape off the black MXene in the middle and upper layers, and freeze-dry to obtain Mxene.

[0016] Preferably, in step (1), the Mxene dispersion is an ethanol dispersion of Mxene. Mix Mxene and ethanol, and ultrasonicate for 20 - 50 min under ice bath conditions to obtain the Mxene dispersion; add WCl 6 to the Mxene dispersion and ultrasonicate for 15 - 30 min under ice bath conditions;

[0017] The mass ratio of Mxene to WCl 6 is 40 - 60: 40 - 400, and the mass ratio of Mxene used to prepare the Mxene dispersion to the volume of ethanol is 40 - 60 mg: 50 - 70 mL.

[0018] Preferably, in step (1), the hydrothermal reaction temperature is 130 - 250 °C, and the reaction time is 24 - 36 h.

[0019] Preferably, the specific process of washing and drying in step (1) is as follows: after the hydrothermal reaction, pour out the upper clear solution, add 50 - 75% (volume fraction) ethanol aqueous solution to the remaining precipitate, ultrasonically oscillate for 10 - 15 min, then centrifuge at 2000 - 3500 rpm for 5 - 10 min, and then pour out the supernatant and dry the precipitate in a vacuum at 60 °C for 20 - 30 h.

[0020] Preferably, in step (2), the calcination temperature is 600 - 800 °C, the time is 3 - 5 h, and the heating rate is 4 - 6 °C / min.

[0021] The present invention also relates to a binary metal oxide composite material prepared by the above preparation method. The W 18 O 49 active component in this composite material is dispersed and fixed on rutile titanium dioxide nanosheets.

[0022] The present invention uses an MXene-based dual precursor to in-situ synthesize this material. Specifically, by exogenously adding MXene, it adsorbs and reduces the tungsten oxide precursor WCl 6The two co-grow in a high-temperature argon atmosphere, MXene is converted into rutile titanium dioxide, and WCl 6 Transformed into oxide-deficient tungsten to achieve in-situ synthesis of R-TiO 2 / W 18 O 49 Micro-nanoscale hybrid composite materials. R-TiO synthesized by this method 2 / W 18 O 49 After high-temperature calcination, the composite material can form a new phase with WC-Ti chemical bonds, which significantly enhances the interfacial electron transfer and the electrical adsorption of heavy metal ions.

[0023] The present invention also relates to the application of the binary metal oxide composite material in removing heavy metal ions in water by electrochemical adsorption. The composite material can be used to prepare the cathode of capacitive deionization (CDI).

[0024] The present invention also relates to a CDI device, comprising a CDI cathode assembly, a silicone pad and a CDI anode assembly, wherein the CDI cathode assembly and the CDI anode assembly are separated by the silicone pad, the CDI cathode assembly is composed of the above-mentioned binary metal oxide composite material and conductive carbon black and a conductive adhesive, and the CDI anode assembly is composed of multi-walled carbon nanotubes, conductive carbon black and a conductive adhesive.

[0025] Preferably, the preparation method of the CDI device comprises the following steps:

[0026] S1, R-TiO 2 / W 18 O 49 The composite material, conductive carbon black and conductive binder Nafion were ultrasonically dispersed in isopropanol; R-TiO 2 / W 18 O 49 The composite material is a binary metal oxide composite material;

[0027] S2, applying the dispersed liquid droplets obtained in step S1 on the surface of the carbon paper electrode and vacuum drying to form a CDI cathode assembly;

[0028] S3, ultrasonically dispersing multi-walled carbon nanotube (MW-CNT) powder, conductive carbon black and conductive binder in isopropanol;

[0029] S4, applying the dispersed liquid droplets obtained in step S3 on the surface of the carbon paper electrode and vacuum drying to form a CDI anode assembly;

[0030] S5. Separate the CDI cathode assembly and the CDI anode assembly using a silicone pad and fix them with a glass plate to build a CDI device.

[0031] Preferably, in step S1, R-TiO 2 / W 18 O 49 The mass ratio of conductive carbon black to binder is 7:1:1-9:1:1, R-TiO 2 / W 18 O 49 The ratio of the mass of to the volume of isopropanol is 20-50 mg: 20-30 mL, and the binder is further preferably Nafion binder or PTFE, and the concentration of Nafion binder is 5wt% (ethanol dispersion).

[0032] Preferably, the ultrasonic dispersion time in step S1 is 10-15 min.

[0033] Preferably, in step S2, the area of ​​the carbon paper is 3-5 cm 2 , vacuum drying temperature is 50-60℃, and drying time is 1-3h.

[0034] Preferably, in step S3, the mass ratio of MW-CNT to conductive carbon black and binder is 7:1:1-9:1:1, the mass ratio of MW-CNT to the volume of isopropanol is 30-70 mg:20-30 mL, the binder is further preferably Nafion binder or PTFE, and the concentration of Nafion binder is 5wt% (ethanol dispersion).

[0035] Preferably, the ultrasonic dispersion time in step S3 is 10-15 min.

[0036] Preferably, in step S4, the area of ​​the carbon paper is 3-5 cm 2 , vacuum drying temperature is 50-60℃, and drying time is 1-3h.

[0037] Preferably, the thickness of the silicone gasket is 0.5-1 mm.

[0038] The beneficial effects of the present invention are:

[0039] (1) Traditional binary composite materials are usually obtained by adsorbing the precursor of another material on one material for in-situ growth. Due to the limited contact area between the two components, it is difficult to effectively improve their overall electrical activity. The present invention discloses a new method for preparing in-situ derived co-growth materials, and obtains a new rutile phase titanium dioxide / oxide-deficient tungsten composite material. The present invention utilizes the excellent adsorption and chemical reducibility of MXene to adsorb WCl 6 The composites of R-TiO 2 / W 18 O 49 The precursor structure of MXene with WCl 6 As R-TiO2 and W 18 O 49 The precursor of R-TiO is prepared by high temperature calcination to form a micro-interface structure containing WC-Ti similar chemical bonds. 2 With W 18 O 49 The co-growth composite forms a single particle of 1-2 microns in size, which greatly improves the charge of R-TiO 2 To W 18 O 49 The transmission distance of the surface sites increases their conductivity by 5-10 times, breaking through the bottleneck of the traditional contact-type composite method that cannot effectively and synchronously improve the conductivity of the active sites.

[0040] (2) The present invention constructs R-TiO for the first time 2 / W 18 O 49 The composite material is used in CDI system to remove heavy metal ions and plays the role of R-TiO 2 The conductivity and W 18 O 49 The composite material constructed by the present invention is used for the CDI cathode to absorb Ni in water. 2+ The removal efficiency is as high as 95%, successfully achieving Ni 2+ The concentration is less than 0.1ppm, which is far better than the existing CDI electrode materials. 18 O 49 The removal rate is less than 80% and cannot meet the emission standards. After high temperature calcination, the electronic interaction between different elements enhances the Ni 2+ affinity, indicating that R-TiO 2 / W 18 O 49 The excellent CDI performance of the composite material is the result of the synergistic effect of double-layer electrosorption and chemical adsorption.

[0041] (3) The present invention uses all-inorganic materials with high conductivity and capacitance, and tungsten and titanium metal oxides have high chemical inertness, so it is not only applicable to the CDI field, but also has the potential to be applied to other electrochemical catalytic systems. For example, it can be coupled with advanced oxidation technology to achieve the oxidation and decomposition of heavy metal organic complexes in electroplating wastewater, while CDI enrichment of heavy metal ions can be performed to achieve the removal of complexed valuable heavy metal ions in wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0043] Figure 1It is a comparison between the traditional composite material and the composite material prepared by the present invention;

[0044] Figure 2 、Etching XRD pattern of MXene;

[0045] Figure 3 MXene / W 18 O 49 、R-TiO 2 / W 18 O 49 Composite materials and W 18 O 49 and XRD patterns of Mxene;

[0046] Figure 4 、Mxene (Figure A), W 18 O 49 (Figure B), MXene / W 18 O 49 (Figure C) and R-TiO 2 / W 18 O 49 SEM image of the composite material (Figure D);

[0047] Figure 5 MXene / W 18 O 49 、R-TiO 2 / W 18 O 49 Composite materials and W 18 O 49 The removal effect of low concentration nickel ions in water using Mxene as CDI cathode;

[0048] Figure 6 , CDI is used for low concentration Ni in water 2+ Schematic diagram of the removal mechanism. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0050] Example 1

[0051] Synthesis of Mxene:

[0052] (1) Add 15 mL of 8 mol / L hydrochloric acid to a polytetrafluoroethylene-lined cup, then add 1.5 g of LiF, and ultrasonically vibrate at 100 Hz for 40 min to obtain a mixed solution.

[0053] (2) Slowly add 1.2g 312 Ti into the mixed solution. 3 AlC 2 , a constant temperature water bath reaction was carried out at a temperature of 35°C and a reaction time of 24 h to obtain a MXene suspension.

[0054] (3) Centrifuge the MXene suspension and wash the MXene precipitate with ultrapure water. Specifically, centrifuge the black solution at 4000 rpm for 7 min, pour out the waste acid, add ultrapure water for washing, and centrifuge several times until the pH is 6. Add 20 mL of ultrapure water to the precipitate, centrifuge at 4000 rpm for 30 min, pour out the gray-black supernatant, scrape off the black MXene in the middle and upper layers, and freeze-dry to obtain MXene.

[0055] R-TiO 2 / W 18 O 49 Synthesis of composite materials:

[0056] (1) First, 50 mg of the prepared MXene was added to a 100 mL reactor liner tube containing 50 mL of anhydrous ethanol and ultrasonically reacted for 40 min under ice bath conditions to fully disperse the MXene, reduce the size of the lamellae, and reduce its oxidation. Then, 50 mg of WCl 6 , continue ice bath and ultrasonic reaction for 20 min to make WCl 6 Fully dissolve; then use MXene as a carrier and reducing agent to synthesize MXene / W 18 O 49 Composite material, the liner tube was placed in a reactor, reacted at 180 ° C for 24 hours, and the reactor was cooled to room temperature, the upper clear solution was poured out, and the obtained precipitate was ultrasonically shaken for 12 minutes with 70% (volume fraction) ethanol aqueous solution, centrifuged at 3000 rpm for 10 minutes, and then the supernatant was poured out and the precipitate was vacuum dried at 60 ° C overnight to obtain MXene: WCl 6 Composite material with a mass ratio of 50:50.

[0057] Similarly, keeping the quality of MXene unchanged, by increasing WCl 6 The mass of MXene / W can be obtained in different mass ratios such as 50:300 and 50:400. 18 O 49 Composite materials.

[0058] (2) Dried MXene: WCl6 The materials with different mass ratios were fully ground separately, calcined at 750 °C for 4 h in an argon atmosphere with a heating rate of 5 °C / min, and MXene and WCl were obtained after cooling to room temperature. 6 R-TiO with different mass ratios 2 / W 18 O 49 Composite materials.

[0059] The R-TiO synthesized above 2 / W 18 O 49 The properties of the composite materials were characterized and analyzed. After the materials were ground uniformly, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed as follows.

[0060] like Figure 2 As shown in the figure, it is the etched XRD pattern of MXene. Compared with the standard PDF card, the Al peak with 2θ=39.78° in the MAX bulk phase completely disappears in the spectrum of MXene. At the same time, the (0 0 2) crystal plane peak with 2θ=9.64° in the MAX bulk phase shifts to the left after being etched into MXene, to the (0 0 2) crystal plane peak with 2θ=7.90° in MXene, proving that the Al in MAX was etched away in the experiment and MXene was successfully synthesized.

[0061] like Figure 3 As shown, the mass ratio of MXene / W is 50:300 18 O 49 、R-TiO 2 / W 18 O 49 Composite material and W in unloaded state 18 O 49 and XRD patterns of Mxene. Among them, W 18 O 49 The preparation method is to add 0.5g WCl 3 Mixed with 50ml water, poured into a polytetrafluoroethylene hydrothermal reactor, after hydrothermal reaction at 200℃ for 24 hours, the liner was dried at 60℃ and placed in a tube furnace for calcination at 750℃ in argon for 3 hours, with a heating rate of 5℃ / min. 18 O 49 After the composite material was calcined, the (0 0 2) crystal plane peak of MXene disappeared, and only the (0 0 6) and (0 1 0) crystal plane peaks of MXene were retained, and these two crystal plane peaks were strengthened. At the same time, the calcined material also retained the W 18 O 49The (2 1 3) crystal plane peak of MXene disappeared after high-temperature calcination, indicating that the material underwent a phase transition; the enhancement of the (0 0 6), (0 10), and (2 1 3) crystal plane peaks indicates that a crystal plane strengthening effect has occurred.

[0062] like Figure 4 As shown, Figure D is MXene / W 18 O 49 The results of calcination at 750℃ show that the surface morphology of the material has changed significantly compared with the uncalcined C figure. 18 O 49 R-TiO obtained after calcination 2 / W 18 O 49 The composite material undergoes phase transformation, indicating the existence of interface enhancement effect.

[0063] Example 2

[0064] The MXene / W in Example 1 with a mass ratio of 50:300 18 O 49 Composite materials for low concentration Ni in water 2+ removal.

[0065] CDI device cathode preparation:

[0066] (1) MXene / W 18 O 49 Conductive carbon black and PTFE adhesive were mixed evenly in a mass ratio of 8:1:1, with a total material mass of 40 mg. The mixture was added into 25 mL of isopropanol and ultrasonically dispersed for 12 min.

[0067] (2) Apply the dispersion obtained in step 1 dropwise on a 4.5 cm 2 The carbon paper electrode surface was vacuum dried at 55°C for 2 h to form a CDI cathode assembly;

[0068] CDI device anode preparation:

[0069] (1) Multi-walled carbon nanotube (MW-CNT) powder, conductive carbon black and conductive binder PTFE were uniformly mixed in a mass ratio of 8:1:1, with a total material mass of 40 mg. The mixture was added to 25 mL of isopropanol and ultrasonically dispersed for 12 min;

[0070] (2) Apply the dispersion obtained in step 1 dropwise on a 4.5 cm 2 The carbon paper electrode surface was vacuum dried at 55°C for 2 h to form a CDI anode assembly;

[0071] CDI device overall assembly:

[0072] The CDI cathode assembly and the CDI anode assembly were separated by a 0.5 mm thick silicone pad and fixed with a glass plate to construct a CDI device.

[0073] CDI nickel removal performance test:

[0074] The applied voltage was 1.2 V, and the peristaltic pump flow rate was set to 40 mL / min. 2+ The removal effect of Figure 5 In addition, the corresponding MXene / W 18 O 49 The composite material is replaced with the same mass of Mxene and W 18 O 49 As a control, a CDI cathode was prepared according to the above method and applied to Ni 2+ The removal effect is also as follows Figure 5 The results show that MXene and W 18 O 49 The performance of both is poor due to the lack of active sites and poor conductivity. 18 O 49 If the precursor and MXene are composited without calcination and co-derivation, the activity of the two is still very poor. In contrast, R-TiO 2 / W 18 O 49 The nickel removal rate of the composite material can reach more than 90%, which can meet the safe discharge standard of nickel wastewater 0.1mg / L. The removal process of nickel ions is very likely to be a low concentration of Ni in water. 2+ The removal is achieved by the coupling of electrosorption and chemical adsorption ( Figure 6 ).

[0075] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for preparing a binary metal oxide composite material, It is characterized in that The following steps are involved: (1) Prepare MXene dispersion first, then add WCl 6 And fully dissolved, using MXene as a carrier and reducing agent for hydrothermal reaction, and then washed and dried to obtain MXene / W 18 O 49 Composite materials; (2) In an argon atmosphere, MXene / W 18 O 49 The composite material is calcined to obtain binary metal oxide R-TiO 2 / W 18 O 49 Composite materials.

2. The preparation method according to claim 1, It is characterized in that The preparation process of the used Mxene of the preparation Mxene dispersion has the following steps: (a) adding LiF to hydrochloric acid and performing ultrasonic vibration to obtain a mixed solution; (b) slowly adding a titanium carbide precursor material to the mixed solution obtained in step (a), and reacting in a constant temperature water bath to obtain a MXene suspension; (c) centrifuging the MXene suspension obtained in step (b), washing the MXene precipitate with ultrapure water, and then freeze-drying to obtain MXene.

3. The preparation method according to claim 2, It is characterized in that In step (a), the concentration of hydrochloric acid is 5.0-9.0 mol / L, the volume ratio of hydrochloric acid to the mass ratio of LiF is 10-20 mL: 0.5-1.5 g; the ultrasonic frequency of ultrasonic oscillation is 100 Hz, and the time is 30-60 min.

4. The preparation method according to claim 2, It is characterized in that In step (b), the titanium carbide synthesis raw material is 312 type Ti 3 AlC 2 The mass ratio of the titanium carbide precursor material to the mass ratio of LiF is 1-1.5:0.5-1.5; the water bath temperature of the constant temperature water bath reaction is controlled at 30-40°C, and the reaction time is 20-30h.

5. The preparation method according to claim 1, It is characterized in that In step (1), the Mxene dispersion is an ethanol dispersion of Mxene, Mxene and ethanol are mixed, and ultrasonicated for 20-50 minutes under ice bath conditions to obtain a Mxene dispersion; WCl 6 Add to the MXene dispersion and sonicate for 15-30 min in an ice bath; Mxene and WCl 6 The mass ratio of MXene to ethanol is 40-60:40-400, and the mass ratio of MXene used to prepare the MXene dispersion to the volume ratio of ethanol is 40-60 mg:50-70 mL.

6. The preparation method according to claim 1, It is characterized in that In step (1), the hydrothermal reaction temperature is 130-250° C. and the reaction time is 24-36 h.

7. The preparation method according to claim 1, It is characterized in that In step (2), the calcination temperature is 600-800°C, the time is 3-5h, and the heating rate is 4-6°C / min.

8. A binary metal oxide composite material, It is characterized in that Prepared by the preparation method according to any one of claims 1 to 7, W 18 O 49 The active components are dispersed and fixed on rutile titanium dioxide nanosheets.

9. Use of the binary metal oxide composite material according to claim 8 in removing heavy metal ions from water by electrochemical adsorption.

10. A CDI device, It is characterized in that The CDI device includes a CDI cathode assembly, a silicone pad and a CDI anode assembly, wherein the CDI cathode assembly and the CDI anode assembly are separated by the silicone pad, the CDI cathode assembly is composed of the binary metal oxide composite material according to claim 8 and conductive carbon black and a conductive adhesive, and the CDI anode assembly is composed of multi-walled carbon nanotubes, conductive carbon black and a conductive adhesive.

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