Ti3C2Tx / AC three-dimensional particle electrode and preparation method and application thereof

Abstract

The invention relates to the technical field of electrochemistry, and particularly discloses a Ti3C2Tx / AC three-dimensional particle electrode and a preparation method and application thereof. The Ti < 3 > C < 2 > T < x > / AC three-dimensional particle electrode provided by the invention comprises Ti < 3 > C < 2 > T < x > and activated carbon. The Ti3C2Tx in the three-dimensional particle electrode provided by the invention has abundant surface active sites and high conductivity, the activated carbon has relatively high specific surface area, adsorption capacity and chemical reactivity, and the two substances supplement each other, so that electrons are efficiently transferred, a remarkable synergistic catalysis effect is shown, and the three-dimensional particle electrode has a good application prospect. The problem that an existing particle electrode is low in O2 and O3 catalytic activity is solved.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical technology, in particular to a Ti3C2T x / AC three-dimensional particle electrode and its preparation method and application. Background Art

[0002] O3 / H2O2 (peroxone) technology In water treatment, the combined reaction of O3 and H2O2 is called the peroxone process. This technology mainly involves O3 and H2O2 through a series of chain reactions, which ultimately produce a large amount of OH with strong oxidizing properties, thereby effectively removing difficult-to-degrade organic matter in wastewater. Since electrocatalytic ozone technology can produce more active substances compared to single ozonation technology, it has been widely used in wastewater treatment. Studies have shown that compared with single ozonation, this method can reduce the total O3 demand by 36% and energy consumption by 28% when the H2O2 / O3 molar ratio is 0.25.

[0003] Although electrocatalytic ozone technology has good performance in removing pollutants, it also has certain defects. For example, the technology is somewhat dependent on the pH value of the solution, and can only exert excellent performance under higher pH conditions. In addition, during the treatment process, H2O2 needs to be manually added quantitatively, and the system can only achieve the best removal effect when it is in the optimal ratio with O3. Large amounts of high-concentration H2O2 pose great risks during transportation, storage and use, which increases operating costs. Therefore, it is necessary to further conduct in-depth research on this basis to develop new, more efficient and safe advanced oxidation technologies.

[0004] At present, electrocatalytic ozonation is achieved by passing a mixed gas of O3 and O2 produced by an ozone generator into the bottom of an electrochemical reactor through an aeration head, causing O2 to undergo a two-electron reduction reaction and convert into H2O2. The in-situ generated H2O2 reacts with the exposed O3 to efficiently produce a large amount of highly oxidizing ·OH, thereby achieving the removal of pollutants. Compared with conventional two-dimensional electrolytic cells, the biggest difference in the three-dimensional electrode electrochemical system is that different types of particle electrodes are filled between the two working electrodes. However, the existing particle electrodes show low catalytic activity for O2 and O3, which affects the treatment effect of wastewater. Therefore, it is of great significance to provide a new three-dimensional particle electrode and its preparation method. Summary of the invention

[0005] In view of the above problems, the present invention provides a Ti3C2T x / AC three-dimensional particle electrode and its preparation method and application.

[0006] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0007] The first aspect of the present invention provides a Ti3C2T x / AC three-dimensional particle electrode, the Ti3C2T x / AC three-dimensional particle electrodes including Ti3C2T x and activated carbon.

[0008] Compared with the prior art, the Ti3C2T x / AC three-dimensional particle electrodes including Ti3C2T x and activated carbon; among them, Ti3C2T x Under the action of voltage, the Ti particle price is Ti 2+ 、Ti 3+ 、Ti 4+ The continuous conversion between Ti3C2T may release oxygen atoms, thereby generating oxygen vacancies. Oxygen vacancies can effectively adjust the electronic structure and density of the particle electrode surface, improve the electron transfer ability of the particle electrode, thereby enhancing electron enrichment and improving the electrochemical performance of the particle electrode. x The surface also has functional groups such as hydroxyl groups and oxides, which can significantly improve the efficiency of electron transfer and catalysis; activated carbon has a high specific surface area and adsorption sites, and can absorb a large amount of oxygen and active ozone molecules, so that the reactants are more concentrated near the catalytic sites, thereby accelerating the electrochemical catalytic efficiency. The surface of activated carbon also has CO and C-OH structures, which provide additional active sites for the decomposition of ozone into OH, which is conducive to accelerating the catalytic reaction rate. The three-dimensional particle electrode provided by the present invention has a high specific surface area and adsorption sites, which can absorb a large amount of oxygen and active ozone molecules, so that the reactants are more concentrated near the catalytic sites, thereby accelerating the electrochemical catalytic efficiency. x Activated carbon has abundant surface active sites and high conductivity, and has a high specific surface area, adsorption capacity and chemical reaction activity. The two substances complement each other, enabling efficient electron transfer and showing significant synergistic catalytic effects, solving the problem of low catalytic activity of current particle electrodes for O2 and O3.

[0009] Further preferably, the Ti3C2T x Ti3C2T / AC three-dimensional particle electrode x The mass ratio of activated carbon is (1-2):(15-16).

[0010] The present invention further defines Ti3C2T x The mass ratio of Ti3C2T x / AC three-dimensional particle electrode catalytic performance, thereby improving the electrochemical performance.

[0011] The second aspect of the present invention provides a Ti3C2T x / The preparation method of AC three-dimensional particle electrode comprises the following steps:

[0012] S1. Add lithium fluoride to a hydrochloric acid solution and react at 38°C-42°C to obtain a reaction solution;

[0013] S2, adding Ti3AlC2 to the reaction solution, reacting at 38°C-42°C, centrifuging the reactant, and then dispersing it in water to obtain Ti3C2T x Dispersion liquid;

[0014] S3, adding activated carbon to the Ti3C2T x The dispersion was kept warm at 20-22°C and dried to obtain Ti3C2T x / AC three-dimensional particle electrode.

[0015] The Ti3C2T provided by the present invention x The preparation method of the AC three-dimensional particle electrode has simple operation steps, low cost and broad application prospects.

[0016] Preferably, in S1, the reaction time is 15 min-18 min.

[0017] Preferably, in S1, the mass volume ratio of the lithium fluoride and the hydrochloric acid solution is 1g:(12.5-13.5)mL, wherein the concentration of the hydrochloric acid solution is 9mol / L-10mol / L.

[0018] Preferably, in S2, the mass volume ratio of Ti3AlC2 and the reaction liquid is 1g:(20-22)mL.

[0019] Preferably, in S2, the reaction time is 48h-50h.

[0020] Preferably, in S2, the reaction can control the rotation speed of the reactor to be 500 rpm.

[0021] Preferably, in S2, the centrifugation condition is: centrifugation is completed until a viscous precipitate appears and the upper liquid begins to turn black.

[0022] Preferably, in S2, the reactants can be centrifuged in a plurality of centrifuge tubes.

[0023] Further preferably, in S2, the specific operation of dispersing in water includes: adding water to the precipitate and then performing ice bath ultrasound.

[0024] Preferably, in S2, the temperature of the ice bath ultrasound is 0°C-15°C, and the time is 1h-1.2h.

[0025] Preferably, in S2, the mass volume ratio of the precipitate to water is 1 g:(25-26) mL.

[0026] Preferably, in S3, the particle size of the activated carbon is 3 mm-5 mm.

[0027] By limiting the particle size of activated carbon, the electrochemical performance of the particle electrode can be further improved.

[0028] Preferably, in S3, the activated carbon and Ti3C2T x Ti3C2T in dispersion x The mass ratio is (15-16):(1-2).

[0029] Preferably, in S3, the insulation time is 24h-26h.

[0030] The third aspect of the present invention provides the Ti3C2T x / Application of AC three-dimensional particle electrode in electrochemical degradation of antibiotic wastewater.

[0031] The three-dimensional particle electrode provided by the present invention is applied to the degradation of antibiotic wastewater, which can significantly improve the removal rate of COD in the antibiotic wastewater.

[0032] Further preferably, the Ti3C2T x / AC three-dimensional particle electrode usage in degradation of antibiotic wastewater is 2g / L-10g / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 CV diagram of the TE-MB-O3 system using the three-dimensional particle electrode provided in Example 1 of the present invention;

[0034] Figure 2 The present invention is 0.1V·S -1 CV graph of TE-MB-O3 at a scan rate of ;

[0035] Figure 3 The present invention is 0.05V·S -1 CV graph of TE-MB-O3 at a scan rate of ;

[0036] Figure 4 The present invention is 0.02V·S -1 CV graph of TE-MB-O3 at a scan rate of ;

[0037] Figure 5 The present invention is 0.01V·S -1 CV graph of TE-MB-O3 at a scan rate of ;

[0038] Figure 6 is a Tafel slope diagram of a TE-MB-O3 system including the three-dimensional particle electrode provided in Example 1 of the present invention;

[0039] Figure 7 It is a Tafel slope diagram of the TE-MB-O3 system including the three-dimensional particle electrode provided in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] In order to better illustrate the present invention, further examples are given below.

[0042] Example 1

[0043] This embodiment provides a Ti3C2T x / AC three-dimensional particle electrodes, including Ti3C2T x and activated carbon;

[0044] The above Ti3C2T x / The preparation method of AC three-dimensional particle electrode comprises the following steps:

[0045] S1. Add 20 g of lithium fluoride to 250 mL of 9 mol / L hydrochloric acid solution, and react at 42° C. for 15 min to obtain a reaction solution;

[0046] S2, adding 10 g of Ti3AlC2 to 220 mL of the reaction solution, reacting at 42° C. for 50 h to obtain a reactant;

[0047] S3, the reactant was centrifuged for the first time until a viscous precipitate appeared and the upper liquid began to turn black, 125 mL of water was added to 5 g of the precipitate, and the reaction mixture was ultrasonicated in an ice bath at 15 ° C for 1 h under an inert gas atmosphere, and then centrifuged for the second time to obtain the upper Ti3C2T x Dispersion liquid;

[0048] S4, add activated carbon with a particle size of 3 mm to the upper layer of Ti3C2T x The dispersion was kept at 20 °C for 24 h and dried to obtain Ti3C2T x / AC three-dimensional particle electrode, in which activated carbon and the upper layer Ti3C2T x Ti3C2T in dispersion x The mass ratio is 15:1.

[0049] Example 2

[0050] This embodiment provides a Ti3C2T x / AC three-dimensional particle electrodes, including Ti3C2T x and activated carbon;

[0051] The above Ti3C2T x / The preparation method of AC three-dimensional particle electrode comprises the following steps:

[0052] S1. Add 20 g of lithium fluoride to 270 mL of 10 mol / L hydrochloric acid solution, and react at 38° C. for 18 min to obtain a reaction solution;

[0053] S2, adding 10 g of Ti3AlC2 to 200 mL of the reaction solution, reacting at 38° C. for 48 h to obtain a reactant;

[0054] S3, the reactant was centrifuged for the first time until a viscous precipitate appeared and the upper liquid began to turn black, 130 mL of water was added to 5 g of the precipitate, and the reaction mixture was ultrasonicated in an ice bath at 0 ° C for 1.2 h under an inert gas atmosphere, and then centrifuged for the second time to obtain the upper Ti3C2T x Dispersion liquid;

[0055] S4, add activated carbon with a particle size of 5 mm to the upper layer of Ti3C2T x The dispersion was kept at 22 °C for 26 h and dried to obtain Ti3C2T x / AC three-dimensional particle electrode, in which activated carbon and the upper layer Ti3C2T x Ti3C2T in dispersion x The mass ratio is 16:2.

[0056] Example 3

[0057] This embodiment provides a Ti3C2T x / AC three-dimensional particle electrodes, including Ti3C2T x and activated carbon;

[0058] The above Ti3C2T x / The preparation method of AC three-dimensional particle electrode comprises the following steps:

[0059] S1. Add 20 g of lithium fluoride to 260 mL of 9.5 mol / L hydrochloric acid solution, and react at 40° C. for 16 min to obtain a reaction solution;

[0060] S2, adding 10 g of Ti3AlC2 to 210 mL of the reaction solution, reacting at 41° C. for 49 h to obtain a reactant;

[0061] S3, the reactant was centrifuged for the first time until a viscous precipitate appeared and the upper liquid began to turn black, 128 mL of water was added to 5 g of the precipitate, and the reaction mixture was ultrasonicated in an ice bath at 10 ° C for 1 h under an inert gas atmosphere, and then centrifuged for the second time to obtain the upper Ti3C2T xDispersion liquid;

[0062] S4, add activated carbon with a particle size of 4 mm to the upper layer of Ti3C2T x The dispersion was kept at 21 °C for 25 h and dried to obtain Ti3C2T x / AC three-dimensional particle electrode, in which activated carbon and the upper layer Ti3C2T x Ti3C2T in dispersion x The mass ratio is 15:2.

[0063] Comparative Example 1

[0064] This comparative example provides a Mn / AC three-dimensional particle electrode, including Mn and activated carbon;

[0065] The preparation method of the Mn / AC three-dimensional particle electrode provided by the present invention comprises the following steps:

[0066] Step 1: Soak 30 g of washed activated carbon in 0.1 mol / L Mn(NO3)2 solution for 12 hours.

[0067] Step 2: Pour out the supernatant and wash with deionized water 2-3 times to remove substances that are not firmly loaded on the activated carbon, and place it in a 105°C oven to dry for 12 hours; after drying, place it in a tubular furnace and calcine it at 500°C for 2 hours in a nitrogen atmosphere to obtain a Mn / AC particle electrode.

[0068] Application Example 1

[0069] The Ti3C2T prepared in Example 1 was subjected to electrochemical workstation. x / AC three-dimensional particle electrode TE-MB-O3 system electrochemical parameters are controlled and tested, such as Figure 1 As shown, by cyclic voltammetry, the electrode Ti3C2T x The TE-MB-O3 system of / AC showed a more significant reduction peak in the potential range of -0.5V-0V Ag / AgCl, which corresponds to the two-electron reaction process of redox, which is similar to the composite Ti3C2T x The oxygen-containing functional groups on the surface of / AC are related to the redox reactions of multiple valence changes of Ti; the TE-MB-O3 system has a higher current response and redox current value, indicating that Ti3C2T x / AC three-dimensional particle electrodes have higher current efficiency and unit space-time yield. Figure 2-5 As shown, at 0.1V·S -1 At high scan rates, the particle electrode Ti3C2T x The CV curves of / AC maintain a good rectangular shape, indicating a small polarization resistance and fast electron transfer ability.

[0070] In order to further evaluate the kinetic performance of the three-dimensional particle electrode material in the electrochemical reaction process, the TE-MB-O3 system using the three-dimensional particle electrode provided in Example 1 of the present invention and the TE-MB-O3 system using the three-dimensional particle electrode provided in Comparative Example 1 of the present invention were tested by Tafel curves. Figure 6-7 As shown, the linear fitting calculation shows that the minimum Tafel slope of the TE-MB-O3 system using the three-dimensional particle electrode provided in Example 1 of the present invention is 31.27 mV·dec -1 The minimum Tafel slope of the TE-MB-O3 system using the three-dimensional particle electrode provided in Comparative Example 1 of the present invention is 34.92 mV·dec -1 The smaller the slope, the more stable and faster the reaction rate of the electrode material is, indicating that the particle electrode Ti3C2T x / AC TE-MB-O3 system has better electron transfer rate and electrochemical reaction kinetics.

[0071] Application Example 2

[0072] 15L of actual antibiotic wastewater was placed in a plexiglass reactor, and carbon felt electrodes fixed with titanium mesh were used as cathode and anode, with a current of 50mA. The ozone addition ratio was adjusted to 1.0, and the ozone flow rate was 0.5L·min -1 , add 2g·L -1 Ti3C2T x / AC three-dimensional particle electrode, after 90 minutes of reaction, the COD removal rate reached 52.22%; 2g·L -1 The Mn / AC three-dimensional particle electrode has a COD removal rate of 42.25% after 90 minutes of reaction. It can be seen that by using the Ti3C2T x / AC three-dimensional particle electrode can significantly improve the COD removal rate during electrochemical degradation of antibiotic water.

[0073] Ti3C2T provided in Examples 1-3 of the present invention x / AC three-dimensional particle electrodes can achieve comparable technical results in detecting electrochemical properties and electrochemical degradation of antibiotic water.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A Ti3C2T x / AC three-dimensional particle electrode, characterized in that The Ti3C2T x / AC three-dimensional particle electrodes including Ti3C2T x and activated carbon.

2. The Ti3C2T as claimed in claim 1 x / AC three-dimensional particle electrode, characterized in that The Ti3C2T x Ti3C2T / AC three-dimensional particle electrode x The mass ratio of activated carbon is (1-2):(15-16).

3. A Ti3C2T3 according to claim 1 or 2 x / The preparation method of AC three-dimensional particle electrode is characterized in that: The steps include: S1. Add lithium fluoride to a hydrochloric acid solution and react at 38°C-42°C to obtain a reaction solution; S2, adding Ti3AlC2 to the reaction solution, reacting at 38°C-42°C, centrifuging the reactant, and then dispersing it in water to obtain Ti3C2T x Dispersion liquid; S3, adding activated carbon to the Ti3C2T x The dispersion was kept warm at 20-22°C and dried to obtain Ti3C2T x / AC three-dimensional particle electrode.

4. Ti3C2T as claimed in claim 3 x / The preparation method of AC three-dimensional particle electrode is characterized in that: In S1, the reaction time is 15 min-18 min; and / or In S1, the mass volume ratio of the lithium fluoride and the hydrochloric acid solution is 1g:(12.5-13.5)mL, wherein the concentration of the hydrochloric acid solution is 9mol / L-10mol / L.

5. Ti3C2T as claimed in claim 3 x / The preparation method of AC three-dimensional particle electrode is characterized in that: In S2, the mass volume ratio of Ti3AlC2 and the reaction liquid is 1g:(20-22)mL.

6. The Ti3C2T3 as claimed in claim 3 x / The preparation method of AC three-dimensional particle electrode is characterized in that: In S2, the reaction time is 48h-50h.

7. The Ti3C2T3 as claimed in claim 3 x / The preparation method of AC three-dimensional particle electrode is characterized in that: In S3, the particle size of the activated carbon is 3mm-5mm.

8. The Ti3C2T3 as claimed in claim 3 x / The preparation method of AC three-dimensional particle electrode is characterized in that: In S3, the activated carbon and Ti3C2T x Ti3C2T in dispersion x The mass ratio is (15-16):(1-2); and / or In S3, the insulation time is 24h-26h.

9. A Ti3C2T3 according to claim 1 or 2 x / AC three-dimensional particle electrode or the Ti3C2T prepared by the preparation method according to any one of claims 3 to 8 x / Application of AC three-dimensional particle electrode in electrochemical degradation of antibiotic wastewater.

10. The use according to claim 9, characterized in that The Ti3C2T x / AC three-dimensional particle electrode usage in degradation of antibiotic wastewater is 2g / L-10g / L.

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