A phosphorus-vacancy-rich F-doped Cu3P chloride ion removal material, its preparation method and application

Abstract

This invention discloses a method for preparing and applying F-doped Cu3P chloride ion removal materials rich in phosphorus vacancies. The method involves preparing Cu3P NA with a nanorod array structure through anodic oxidation and low-temperature phosphating, and using a molten salt-induced method to achieve fluorine doping and induce adaptive phosphorus vacancy generation. By strictly controlling the phosphating amount and molten salt reaction time, F-Cu3P with a nanorod array structure and a dual defect of fluorine doping and phosphorus vacancies is obtained. V This method is not only simple to operate but also requires minimal equipment, making it potentially suitable for industrial application. The unique low-torsivity nanorod array structure and the fluorine-doped phosphorus vacancy dual-defect structure with tunable electronic structure facilitate the exposure of active sites and accelerate charge migration rates, thus enabling the preparation of synthesized F-Cu3P... V The self-supporting electrode exhibits excellent area performance in chloride ion removal.

Description

Technical Field

[0001] This invention belongs to the field of environmental material synthesis technology, specifically relating to an F-doped Cu3P chloride ion removal material rich in phosphorus vacancies, its preparation method, and its application. Background Technology

[0002] Industrial wastewater has become a major source of water pollution in my country, with chlorine-containing wastewater accounting for a high proportion and originating from a wide range of sources. Chloride ions (Cl...) - Not only does it corrode metal equipment and affect industrial production, but it also leads to water pollution, disrupts the ecological balance, causes soil salinization, and harms land resources and plant growth. Therefore, Cl - Highly efficient chlorine removal is crucial for ensuring industrial production and protecting the ecological environment. Currently, traditional precipitation and evaporation concentration methods are limited by reagent and equipment costs, making them suitable only for small volumes of high-concentration wastewater. Reverse osmosis technology also faces challenges related to membrane fouling. Unlike these traditional chlorine removal technologies, capacitive deionization (CDI), combining electrochemical theory with adsorption separation technology, offers advantages such as no secondary pollution, easy regeneration, long cycle life, and low energy consumption. - It shows great application potential in removal.

[0003] However, traditional carbon electrode materials for CDI store ions through an electric double-layer mechanism, which suffers from drawbacks such as low capacity, lack of selectivity, and low charge efficiency. Faraday electrode materials have attracted attention due to their large adsorption capacity and selectivity for specific anions and cations, but research has largely focused on cathode materials, neglecting anode materials. Existing dechlorination electrode materials, such as Ag / AgCl and Bi / BiOCl, suffer from high cost, slow reaction rates, and poor cycle performance. Therefore, there is an urgent need to develop novel, efficient, and stable dechlorination materials to meet the needs of practical applications. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the primary objective of this invention is to provide a chloride ion removal material – F-doped Cu3P rich in phosphorus vacancies (F-Cu3P). V ).

[0005] The second objective of this invention is to provide the aforementioned chloride ion removal material F-Cu3P. V Preparation method of .

[0006] A third objective of this invention is to provide the aforementioned chloride ion removal material F-Cu3P. V Its uses.

[0007] To achieve the above objectives, the solution of the present invention is: A method for preparing an F-doped Cu3P chloride ion removal material rich in phosphorus vacancies, comprising the following steps: S1. The copper foam was anoly oxidized in an alkaline solution, washed, and vacuum dried to obtain a self-supporting Cu(OH)2 nanowire array. S2. A certain amount of sodium hypophosphite is placed in the middle of a tube furnace, and the Cu(OH)2 nanowire array is placed downstream. Phosphating reaction is carried out under the protection of a certain temperature and an inert gas to obtain self-supporting Cu3P NA with a nanorod array structure. S3. A certain amount of ammonium fluoride is melted at a certain temperature, and Cu3PNA is added. After reacting for a certain time, the mixture is removed, washed, and vacuum dried to obtain F-Cu3P with both fluorine doping and phosphorus vacancy defects. V .

[0008] As one implementation, in step S1, the alkaline solution is a 2-4 M NaOH solution.

[0009] As one implementation, in step S1, the current used for anodizing is 10~20 mA, and the anodizing time is 10-30 min.

[0010] As one implementation scheme, in step S1, the vacuum drying temperature is 20-70 ℃ and the time is 8-24 h.

[0011] As one implementation scheme, in step S2, the amount of sodium hypophosphite is 150–300 mg / 1.5 cm. 2 .

[0012] As one implementation scheme, in step S2, the parameters of the phosphating reaction are: heating rate 1-3℃ / min, reaction temperature 250-300℃, and reaction time 1-2 h.

[0013] As one implementation scheme, in step S3, the amount of ammonium fluoride is 10-20 g / 9 cm. 2 The melting temperature is 140-160 ℃.

[0014] As one implementation scheme, in step S3, the reaction time is 10~50 min.

[0015] A chloride ion removal material F-Cu3P obtained by the above preparation method V The use of [the material] as an anode in capacitive deionization and in dechlorination is within the scope of protection of this invention.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) Based on the dual-defect strategy of heteroatom doping-induced vacancies, F-doping and P vacancies were simultaneously introduced into Cu3P nanorod arrays through molten salt treatment, and F-Cu3P was successfully prepared. VTheoretical calculations and experimental results show that the introduction of highly electronegative F doping into Cu3P induces lattice distortion and induces electron transfer from Cu to F, which weakens the Cu-P covalent bond energy and thus promotes the formation of P vacancies.

[0017] (2) The dual defects constructed by F doping and P vacancy effectively induce the electronic distribution of Cu3P, thereby optimizing its conductivity, adsorption energy and migration barrier for chloride ions, thus significantly improving the removal performance of chloride ions.

[0018] (3) Using Cu3P nanoarrays with double defects as dechlorination electrodes can achieve excellent area dechlorination performance, which is about 60% higher than that of Cu3P nanoarrays, which is conducive to promoting practical applications.

[0019] (4) The preparation method of the present invention uses simple equipment and the process is simple and easy to implement. It can be operated continuously, thus making it suitable for large-scale production. Attached Figure Description

[0020] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 The chloride ion removal material F-Cu3P of the present invention V XRD pattern; Figure 2 The chloride ion removal material F-Cu3P of the present invention V SEM image; Figure 3 The chloride ion removal material F-Cu3P of the present invention V EPR diagram; Figure 4 The chloride ion removal material F-Cu3P of the present invention V Chloride ion removal capacity and rate at a given voltage; Figure 5 The comparative material of this invention is S-Cu3P V A graph showing the chloride ion removal capacity and rate at a given voltage. Detailed Implementation

[0021] The present invention will be described in detail below with reference to embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several adjustments and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0022] The following examples involve the chloride ion removal material F-Cu3P V The preparation method includes the following steps: (1) The cleaned foamed copper was anodized in an alkaline solution, washed, and dried to obtain a self-supporting Cu(OH)2 nanowire array.

[0023] (2) A certain amount of sodium hypophosphite is placed upstream of a tube furnace, and the Cu(OH)2 nanowire array obtained in step 1) is placed downstream. Phosphating reaction is carried out under a certain temperature and inert gas protection to obtain self-supporting Cu3P NA with nanorod array structure.

[0024] (3) A certain amount of NH4F is melted at a certain temperature, and Cu3P NA obtained in step 2) is added. After reacting for a certain time, it is taken out, washed, and dried to obtain F-Cu3P with fluorine doping-phosphorus vacancy dual defects. V .

[0025] In fact, a phosphating reaction occurred in step (2). Sodium hypophosphite decomposed under high temperature conditions to release PH3 gas, which reacted with Cu(OH)2 in the tubular furnace with the protective gas to generate Cu3P.

[0026] In step (1), the alkaline solution is a 3 M NaOH solution, the current is 10~20 mA, and the anodizing time is 10 min.

[0027] In step (2), the amount of sodium hypophosphite is 150~300 mg / 1.5 cm. 2 The heating rate was 2℃ / min, the reaction temperature was 300℃, and the reaction time was 2 h.

[0028] In step (3), the amount of ammonium fluoride is 20 g, the reaction temperature is 150℃, and the reaction time is 10~50 min.

[0029] Example 1 The preparation method of the chloride ion removal material F-Cu3PV in this embodiment includes the following steps: (1) Cut 0.8 mm thick copper foam into 1 cm × 2 cm pieces, and wash them with ethanol, 1 M hydrochloric acid and deionized water in sequence to remove impurities and oxides on the surface. After washing, dry them at room temperature. The cleaned copper foam is anolyzed in 3 M NaOH solution at 20 mA for 10 min (the cathode is a titanium sheet). After washing and drying, a self-supporting Cu(OH)2 nanowire array is obtained.

[0030] (2) 200 mg / 1.5 cm 2Sodium hypophosphite was placed upstream of a tube furnace, and the Cu(OH)2 nanowire array obtained in step 1) was placed downstream. Under the protection of inert gas Ar, the temperature was increased to 300℃ at a rate of 2℃ / min for 2h for phosphating reaction. After natural cooling, self-supporting Cu3P NA with nanorod array structure was obtained.

[0031] (3) 20 g of NH4F was melted at 150 °C, and Cu3P NA obtained in step 2) was added. After reacting for 20 min, the mixture was removed, washed, and dried to obtain F-Cu3P with fluorine doping-phosphorus vacancy dual defects. V .

[0032] like Figure 1 As shown, F-Cu3P prepared according to the above method V The XRD diffraction peaks are almost identical to the standard peaks in the standard card PDF#71-2261 of Cu3P, indicating that the crystal structure of Cu3P obtained by this preparation method is indeed Cu3P.

[0033] like Figure 2 As shown, F-Cu3P prepared according to the above method V SEM tests showed that Cu3P is a nanorod array structure with low tortuosity.

[0034] like Figure 3 As shown, F-Cu3P can be seen. V A strong signal is present at g=2.01, indicating the presence of phosphorus vacancies.

[0035] like Figure 4 As shown, at a voltage of 1.0 V, F-Cu3P V The chlorine removal surface area capacity can reach ~2.41 mg-Cl. cm 2 The corresponding dechlorination rate is ~0.081 mg-Cl. cm 2 min 1 At 1.6 V, the highest area deionization capacity reached 4.09 mg-Cl. cm 2 And the corresponding highest deionization rate reached 0.137 mg-Cl. cm 2 min 1 .

[0036] Example 2 The chloride ion removal material F-Cu3P in this embodiment V The preparation method includes the following steps: (1) Cut 0.8 mm thick copper foam into 1 cm × 2 cm pieces, wash them with ethanol, 1 M hydrochloric acid and deionized water in sequence, and dry them at room temperature; anoly oxidize the washed copper foam in 3 M NaOH solution at 20 mA for 10 min, wash and dry to obtain a self-supporting Cu(OH)2 nanowire array.

[0037] (2) 200 mg / 1.5 cm 2 Sodium hypophosphite was placed upstream of a tube furnace, and the Cu(OH)2 nanowire array obtained in step 1) was placed downstream. Under the protection of inert gas Ar, the temperature was increased to 300℃ at a rate of 2℃ / min for 2h for phosphating reaction. After natural cooling, self-supporting Cu3P NA with nanorod array structure was obtained.

[0038] (3) Melt 20 g of NH4F at 150 °C, add Cu3P NA obtained in step 2), react for 10 min, remove, wash, and dry to obtain F-Cu3P with fluorine doping-phosphorus vacancy dual defects. V -1.

[0039] Example 3 The chloride ion removal material F-Cu3P in this embodiment V The preparation method includes the following steps: (1) Cut 0.8 mm thick copper foam into 1 cm × 2 cm pieces, wash them with ethanol, 1 M hydrochloric acid and deionized water in sequence, and dry them at room temperature; anoly oxidize the washed copper foam in 3 M NaOH solution at 20 mA for 10 min, wash and dry to obtain a self-supporting Cu(OH)2 nanowire array.

[0040] (2) 200 mg / 1.5 cm 2 Sodium hypophosphite was placed upstream of a tube furnace, and the Cu(OH)2 nanowire array obtained in step 1) was placed downstream. Under the protection of inert gas Ar, the temperature was increased to 300℃ at a rate of 2℃ / min for 2h for phosphating reaction. After natural cooling, self-supporting Cu3P NA with nanorod array structure was obtained.

[0041] (3) 20 g of NH4F was melted at 150 °C, and Cu3P NA obtained in step 2) was added. After reacting for 50 min, the mixture was removed, washed, and dried to obtain F-Cu3P with fluorine doping-phosphorus vacancy dual defects. V -2.

[0042] Comparative Example 1 The chloride ion removal material S-Cu3P in this comparative example V The preparation method includes the following steps: (1) Cut 0.8 mm thick copper foam into 1 cm × 2 cm pieces, wash them with ethanol, 1 M hydrochloric acid and deionized water in sequence, and dry them at room temperature; anoly oxidize the washed copper foam in 3 M NaOH solution at 20 mA for 10 min, wash and dry to obtain a self-supporting Cu(OH)2 nanowire array.

[0043] (2) 200 mg / 1.5 cm 2 Sodium hypophosphite was placed upstream of a tube furnace, and the Cu(OH)2 nanowire array obtained in step 1) was placed downstream. Under the protection of inert gas Ar, the temperature was increased to 300℃ at a rate of 2℃ / min for 2h for phosphating reaction. After natural cooling, self-supporting Cu3P NA with nanorod array structure was obtained.

[0044] (3) Place half the mass of Cu3P NA in the upstream of a tube furnace and place the Cu3P NA obtained in step 2) in the downstream. Heat the furnace to 300°C at a rate of 2°C / min. After reacting for 1 hour, remove the furnace to obtain sulfur-doped S-Cu3P. V .

[0045] Depend on Figure 4 and Figure 5 The comparison shows that doping with thiourea as a dopant, performed at 300℃ for 1 hour, yields better performance than Cu3P, but not as good as F-Cu3P. V Difference.

[0046] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing F-doped Cu3P rich in phosphorus vacancies, characterized in that, The method includes the following steps: S1. The copper foam was anoly oxidized in an alkaline solution, washed, and vacuum dried to obtain a self-supporting Cu(OH)2 nanowire array. S2. A certain amount of sodium hypophosphite is placed in the middle of a tube furnace, and the Cu(OH)2 nanowire array is placed downstream. Phosphating reaction is carried out under the protection of a certain temperature and an inert gas to obtain self-supporting Cu3P NA with a nanorod array structure. S3. A certain amount of ammonium fluoride is melted at a certain temperature, and Cu3PNA is added. After reacting for a certain time, the mixture is removed, washed, and vacuum dried to obtain F-Cu3P with both fluorine doping and phosphorus vacancy defects. V .

2. The method for preparing F-doped Cu3P rich in phosphorus vacancies according to claim 1, characterized in that, In step S1, the alkaline solution is a 2-4 M NaOH solution; the current used for anodizing is 10-20 mA, and the anodizing time is 10-30 min.

3. The method for preparing F-doped Cu3P rich in phosphorus vacancies according to claim 1, characterized in that, In step S1, the vacuum drying temperature is 20-70 ℃ and the time is 8-24 h.

4. The method for preparing F-doped Cu3P rich in phosphorus vacancies according to claim 1, characterized in that, In step S2, the amount of sodium hypophosphite is 150–300 mg / 1.5 cm. 2 .

5. The method for preparing F-doped Cu3P rich in phosphorus vacancies according to claim 1, characterized in that, In step S2, the parameters of the phosphating reaction are: heating rate 1-3℃ / min, reaction temperature 250-300℃, and reaction time 1-2 h.

6. The method for preparing F-doped Cu3P rich in phosphorus vacancies according to claim 1, characterized in that, In step S3, the amount of ammonium fluoride is 10-20 g / 9 cm. 2 The melting temperature is 140-160 ℃.

7. The method for preparing F-doped Cu3P rich in phosphorus vacancies according to claim 1, characterized in that, In step S3, the reaction time is 10~50 min.

8. An F-doped Cu3P rich in phosphorus vacancies, characterized in that, Prepared by the method described in any one of claims 1-7.

9. The application of F-doped Cu3P rich in phosphorus vacancies as described in claim 8 in capacitor deionization and chlorine removal.

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