Method for photochemically driving efficient degradation of perfluoroalkyl / polyfluoroalkyl compound and application

Abstract

The invention discloses a method for photochemically driving efficient degradation of perfluoroalkyl / polyfluoroalkyl compounds PFAS, which comprises the following steps: mixing transition metal salt with a PFAS solution to form a coordination compound, starting a degradation reaction under the irradiation of a 220-455nm light source, quickly degrading the PFAS into short-chain PFAS, and finally mineralizing the short-chain PFAS into fluorine ions and carbon dioxide. The PFAS degradation method disclosed by the invention is low in energy consumption and high in defluorination efficiency, overcomes the technical bottlenecks of low defluorination efficiency, high energy consumption, easiness in being influenced by coexisting species and the like in a traditional PFAS degradation method, is suitable for various types of PFAS, and particularly has a remarkable effect on treatment of short-chain and ultra-short-chain PFAS.

Description

Technical Field

[0001] The present invention relates to the technical field of per / polyfluoroalkyl compound pollution control, and in particular to a method and application for efficient photo-driven degradation of PFAS under the catalysis of transition metal salts. Background Art

[0002] Per- and polyfluoroalkyl compounds (PFAS) are a class of synthetic fluorinated organic compounds that are structurally composed of hydrophilic functional groups and hydrophobic alkane chains, in which all or part of the H atoms on the alkane chains are replaced by F atoms. This unique structure gives PFAS excellent hydrophobic and oleophobic properties. Since their synthesis in the 1940s, they have been widely used in everyday products such as foam fire extinguishing agents, non-stick cookware, paper, textiles, electronic products, and coatings. However, the widespread use and high stability of PFAS have caused major environmental and public health problems, and technologies for the efficient removal of PFAS from the environment are urgently needed.

[0003] Various treatment technologies, including electrochemical, advanced oxidation and reduction, sonochemical, and thermochemical treatments, have been studied for the degradation of PFAS. However, due to high energy requirements, the formation of refractory intermediates, and interference from complex matrices, these chemical technologies often fail to achieve efficient degradation and complete mineralization of PFAS in aqueous environments. Currently, non-destructive technologies such as carbon adsorption, membrane filtration, and ion exchange systems are widely used to remove PFAS from water. However, these physical removal methods produce highly concentrated eluents (such as methanol (MeOH) and acetonitrile (MeCN)), which require further treatment to prevent secondary contamination.

[0004] Therefore, in response to the above problems, it is necessary to develop an efficient degradation application technology for PFAS in the eluate, which can completely mineralize PFAS in the eluate at low energy consumption, and has important economic and environmental significance. Summary of the Invention

[0005] Based on the defects of the above-mentioned prior art, the purpose of the present invention is to provide a method and application for photochemically driven efficient degradation of PFAS, aiming to solve the technical problems that existing PFAS degradation methods cannot achieve low energy consumption and complete degradation and mineralization of PFAS.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, a method for photochemically driven efficient degradation of PFAS comprises the following steps:

[0008] S1: Preparation of reaction solution: Add transition metal salt ions and inorganic base to the eluent containing PFAS and stir evenly to form [transition metal salt ions-PFAS] + complex reaction solution;

[0009] S2: Add the above reaction solution into a quartz container, and start and carry out the PFAS degradation reaction under the irradiation of a light source in the wavelength range of 220-455nm.

[0010] Preferably, PFAS can eventually generate fluoride ions (F - ) and carbon dioxide (CO2) to achieve complete mineralization.

[0011] Preferably, as a preferred embodiment, in step S1, the transition metal salt ion includes one or more of copper salt, iron salt or cerium salt;

[0012] Preferably, the copper salt is a divalent copper salt (Cu 2+ ), the iron salt is a trivalent iron salt, and the cerium salt is a trivalent cerium salt;

[0013] Preferably, the divalent copper salt (Cu 2+ ), including but not limited to copper trifluoromethanesulfonate (Cu(OTf)2) or copper tetrafluoroborate (Cu(BF4)2);

[0014] The trivalent iron salt includes but is not limited to iron trifluoromethanesulfonate (Fe[OTf]3) or iron chloride (FeCl3);

[0015] The trivalent cerium salt includes, but is not limited to, cerium trifluoromethanesulfonate (Ce[OTf]3) or cerium chloride (CeCl3).

[0016] Preferably, as a preferred embodiment, in step S1, the inorganic base includes but is not limited to sodium hydroxide (NaOH), potassium hydroxide (KOH) or ammonia water (NH4OH).

[0017] Preferably, as a preferred embodiment, in step S1, PFAS includes but is not limited to perfluoroalkyl carboxylic acids or perfluoroether carboxylic acid compounds with a carbon chain length of 2-12.

[0018] Preferably, as a preferred embodiment, in step S1, the molar ratio of the transition metal salt ion to PFAS is 0.1:1 to 2:1, and the molar ratio of the inorganic base to PFAS is 0.1:1 to 1:1.

[0019] Preferably, as a better embodiment, in step S1, the PFAS concentration is 0.01 mM to 50 mM.

[0020] Preferably, as a preferred embodiment, in step S1, the eluent includes but is not limited to acetonitrile (MeCN), dimethylformamide (DMF) or methanol (MeOH).

[0021] Preferably, as a better embodiment, in step S2, the reaction time is 24h-48h.

[0022] Preferably, as a preferred embodiment, in step S2, the light source includes but is not limited to a high-pressure mercury lamp, a xenon lamp, an LED lamp or a solar simulator.

[0023] The second aspect is the application of the aforementioned photochemically driven PFAS efficient degradation method in the degradation of PFAS.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The light-driven PFAS degradation method of the present invention is to 2+ 、Fe 3+ 、Ce 3+ The transition metal salt ions coordinate with PFAS, and the degradation reaction proceeds under mild conditions, and finally all F - The PFAS degradation method proposed in this paper is simple, easy to operate, and has a wide range of applications. It overcomes the problem of PFAS being difficult to degrade and prone to secondary pollution, and can achieve complete mineralization in a gentle manner.

[0026] (2) The PFAS degradation method introduced in the present invention is applicable to various types of PFAS and can achieve complete defluorination. Compared with the existing technology that short-chain and ultra-short-chain PFAS are extremely difficult to degrade, the technology proposed in the present invention has a faster degradation rate for PFAS of the same type with shorter chain lengths, overcoming the problems of difficult complete defluorination of PFAS and easy residual short-chain PFAS in traditional technologies. In addition, the catalyst is a commercial transition metal salt such as copper salt, iron salt, cerium salt, etc., which is cheap and easy to obtain. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is an analysis of the PFOA degradation process in Example 1. (a) and (b) are HPLC-MS / MS chromatograms of PFOA photochemical degradation at 365 nm at 0 h and 8 h, respectively. (c) and (d) show the changes in the concentration of PFOA degradation intermediates and the F mass balance over time, respectively. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The present invention is further described in detail below. Unless otherwise specified, the chemical substances of the present invention can be purchased from commercial sources.

[0029] Example 1

[0030] 0.2mmol Cu[OTf]2 and 0.1mmol NaOH were added to 10mL MeCN solution containing 0.1mmol PFOA, and the reaction solution was formed after shaking. The reaction solution was added to a quartz test tube and heated at an irradiance of 100mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with wavelengths of 254, 305, 365, 395, and 405 nm. Reaction conditions: magnetic stirring at 500 rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - and PFOA concentrations, and calculated the degradation rate and defluorination rate.

[0031] Example 2

[0032] 0.2 mmol of Cu(BF4)2, Cu(OTf)2, Fe[OTf]3, FeCl3, Ce[OTf]3 or CeCl3 was added to 10 mL of MeCN solution containing 0.1 mmol of NaOH and 0.1 mmol of PFOA, respectively. After shaking, the reaction solution was added to a quartz test tube and heated at an irradiance of 100 mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - and PFOA concentrations, and calculated the degradation rate and defluorination rate.

[0033] Example 3

[0034] 0.1 mmol of NaOH, KOH or NH4OH was added to 10 mL of MeCN solution containing 0.2 mmol of Cu(OTf)2 and 0.1 mmol of PFOA, respectively. After shaking, a reaction solution was formed. The reaction solution was added to a quartz test tube and heated at an irradiance of 100 mW / cm 2The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - and PFOA concentrations, and calculated the degradation rate and defluorination rate.

[0035] Example 4

[0036] 0.2 mmol Cu[OTf]2 and 0.1 mmol NaOH were added to 10 mL MeCN solution containing 0.1 mmol trifluoroacetic acid (TFA), heptafluorobutyric acid (PFBA), perfluorohexanoic acid (PFHxA), PFOA, perfluoro-4-methoxybutyric acid (PFMOBA) or perfluoro-2-methyl-3-oxahexanoic acid (GenX), respectively. After shaking, the reaction solution was added to a quartz test tube and heated under an irradiance of 100 mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - and PFOA concentrations, and calculated the degradation rate and defluorination rate.

[0037] Example 5

[0038] 0.01mmol, 0.05mmol, 0.1mmol, 0.15mmol and 0.2mmol of Cu(OTf)2 were added to 10mL MeCN solution containing 0.1mmol NaOH and 0.1mmol PFOA, respectively. After shaking, the reaction solution was added to a quartz test tube and heated at an irradiance of 100mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - and PFOA concentrations, and calculated the degradation rate and defluorination rate.

[0039] Example 6

[0040] 0.01mmol, 0.03mmol, 0.05mmol, 0.08mmol and 1mmol of NaOH were added to 10mL MeCN solution containing 0.2mmolCu(OTf)2 and 0.1mmolPFOA, respectively. After shaking, the reaction solution was added to a quartz test tube and heated at an irradiance of 100mW / cm 2The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - and PFOA concentrations, and calculated the degradation rate and defluorination rate.

[0041] Comparative Example 1

[0042] 0.2mmol Cu[OTf]2 and 0.1mmol NaOH were added to 10mL acetonitrile solution containing 0.1mmol PFOA, and the reaction solution was formed after shaking. The reaction solution was added to a quartz test tube and heated at an irradiance of 100mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 500nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 1.

[0043] Comparative Example 2

[0044] 0.1 mmol NaOH was added to 10 mL MeCN solution containing 0.1 mmol PFOA, and the reaction solution was formed after shaking. The reaction solution was added to a quartz test tube and heated at an irradiance of 100 mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 2.

[0045] Comparative Example 3

[0046] 0.4 mmol NaOH was added to 10 mL MeCN solution containing 0.1 mmol PFOA, and the reaction solution was formed after shaking. The reaction solution was added to a quartz test tube and heated at an irradiance of 100 mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 2.

[0047] Comparative Example 4

[0048] 0.2 mmol Cu[OTf]2 was added to 10 mL MeCN solution containing 0.1 mmol PFOA, and the reaction solution was formed after shaking. The reaction solution was added to a quartz test tube and heated at an irradiance of 100 mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 3.

[0049] Comparative Example 5

[0050] 0.4 mmol Cu[OTf]2 was added to 10 mL MeCN solution containing 0.1 mmol PFOA, and the reaction solution was formed after shaking. The reaction solution was added to a quartz test tube and heated at an irradiance of 100 mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 3.

[0051] Comparative Example 6

[0052] 0.005mmol and 0.25mmol of Cu(OTf)2 were added to 10mL of MeCN solution containing 0.1mmol of NaOH and 0.1mmol of PFOA, respectively. After shaking, the reaction solution was added to a quartz test tube and heated at an irradiance of 100mW / cm 2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 5.

[0053] Comparative Example 7

[0054] 0.005mmol and 0.15mmol of NaOH were added to 10mL of MeCN solution containing 0.2mmol of Cu(OTf)2 and 0.1mmol of PFOA, respectively. After shaking, the reaction solution was added to a quartz test tube and heated at an irradiance of 100mW / cm2 The degradation reaction was carried out under the irradiation of LED light with a wavelength of 365nm. Reaction conditions: magnetic stirring at 500rpm / min, cooling fan to control the temperature at 22±0.5℃, and direct exposure to air atmosphere. Samples were taken after 8h and 24h of reaction, and F - The degradation rate and defluorination rate were calculated based on the concentration of PFOA. The results were compared with those in Example 6.

[0055] The performance tests of the embodiments and comparative examples are shown in Table 1.

[0056] Table 1 Degradation rate and defluorination rate of PFOA within 8h and 24h under different light wavelengths

[0057]

[0058]

[0059] Table 2 Degradation rate and defluorination rate of PFOA within 8 h and 24 h under the addition of different transition metal salts

[0060]

[0061] Table 3 Degradation rate and defluorination rate of PFOA within 8 h and 24 h under different inorganic base additions

[0062]

[0063] Table 4 Degradation rate and defluorination rate of different PFAS in the reaction system within 8 h and 24 h

[0064]

[0065] Table 5 Degradation rate and defluorination rate of PFOA within 8 h and 24 h under different transition metal salt concentrations

[0066]

[0067] Table 6 Degradation rate and defluorination rate of PFOA within 8 h and 24 h under different inorganic base concentrations

[0068]

[0069] As shown in Table 1, different wavelengths of light sources significantly affect the performance of the photochemical reaction system. In Example 1, PFOA can be effectively degraded using LED light sources with wavelengths of 254-405 nm. The best effect was achieved at a wavelength of 365 nm, with a degradation rate exceeding 95% and a defluorination rate exceeding 43% in 8 hours. Complete degradation and defluorination can be achieved in 24 hours, indicating that 365 nm photon energy is most suitable for [Cu-PFOA]. +Degradation process of the composite. In Comparative Example 1, an LED light source with a wavelength of 500 nm was used. The results showed that its degradation rate and defluorination rate were significantly lower than those of Example 1, and only weak PFOA degradation was detected, indicating that the photon energy at this wavelength was insufficient to effectively drive degradation.

[0070] As shown in Table 2, various transition metal salts can effectively degrade PFOA. In Example 2, different transition metal salts were added. Under 365nm LED irradiation, four Cu 2+ and Fe 3+ The salts all showed excellent PFOA degradation and defluorination capabilities, achieving >90% degradation and defluorination within 24 hours. 3+ Salt was slightly less effective, but still achieved >86.2% degradation and >46.5% defluorination within 24 hours. Comparative Examples 2 and 3, which did not add any metal salts, showed little PFOA degradation or defluorination within the same reaction time, indicating that NaOH and light alone are insufficient to drive PFOA degradation, demonstrating that the introduction of transition metal ions plays a key role in this photocatalytic system.

[0071] As shown in Table 3, the addition of alkali is crucial to the degradation efficiency of PFOA. After adding NaOH, KOH and NH4OH respectively in Example 3, the PFOA degradation rate of more than 94% was achieved within 8 hours, and the degradation rate exceeded 99.9% after 24 hours; the corresponding defluorination rate also reached more than 43.8% in 8 hours, and exceeded 99.9% in 24 hours, showing extremely high degradation efficiency and mineralization ability. In contrast, in Comparative Examples 4 and 5 where no inorganic base was added, the degradation reaction efficiency of PFOA was significantly limited. This is because only with the assistance of the base can PFOA be deprotonated to form anions, which can effectively coordinate with transition metal ions. It is verified again that the formation of transition metal-PFOA complex is a key step in photochemical degradation.

[0072] It can be seen from Examples 1-6 and Comparative Examples 3 and 5 that there is a synergistic effect between the inorganic base and the transition metal salt, achieving the technical effect of 1+1>2.

[0073] As shown in Table 4, various PFASs were effectively degraded in this system, with short-chain and ultra-short-chain PFAS being particularly effective. In Example 4, the Cu[OTf]2 / NaOH system demonstrated excellent degradation performance against a wide range of PFAS structures. Within an 8-hour reaction time, the degradation rates of TFA, PFMOBA, and GenX reached >99.9%, 98.8%, and 97.2%, respectively. The degradation rates of short-chain PFBA, PFHxA, and long-chain PFOA also reached 98.2%, 96.8%, and 95.2%, respectively. After 24 hours of reaction, the degradation rate of all PFAS exceeded 99.9%. Although there were differences in the initial defluorination degree, the defluorination rate of all PFAS exceeded 99.9% after 24 hours, verifying that the system has the ability to efficiently and completely degrade and defluorinate a variety of PFAS. It is not only suitable for traditional long, short and ultra-short chain PFAS, but also shows excellent adaptability and treatment efficiency for new alternatives such as GenX and PFMOBA, providing a new PFAS degradation technology with strong universality and thorough defluorination.

[0074] As shown in Table 5, different concentrations of transition metal salts have a significant effect on the degradation effect of the photochemical reaction system. Within the preferred concentration range of the present invention, PFOA can achieve efficient degradation and defluorination. In Example 5, as the concentration of Cu(OTf)2 increases, the degradation rate and defluorination rate of PFOA within 8h and 24h are significantly improved. When the initial concentration is 0.01mmol, the degradation rate within 24h is 90.3% and the defluorination rate is 43.6%; after increasing to 0.1mmol, the degradation rate reaches 95.6% and the defluorination rate rises to 76.1%, indicating that the appropriate amount of metal salt can effectively stimulate the LMCT process and promote the reaction. Between 0.1 and 0.2mmol, the degradation rate increases slowly (>99.9% in 24h), but the defluorination rate still increases significantly (76.1% to 99.9%), indicating that high concentration helps to completely break the C-F bond and promote complete mineralization. In Comparative Example 6, the degradation and defluorination rates at a concentration of 0.005 mmol were extremely low, essentially preventing the reaction from proceeding. Furthermore, the effect of 0.25 mmol was worse than that of 0.2 mmol, indicating that excessive addition had no significant benefit, but instead reduced the catalytic effect and increased transition metal salt consumption. In summary, metal salt concentration is a key factor in regulating the performance of this system: too low a concentration makes it difficult to effectively drive LMCT, while too high a concentration results in no benefit. The optimal concentration range (0.1–0.2 mmol) balances degradation efficiency and economics, providing a reference for efficient PFAS treatment.

[0075] As shown in Table 6, the addition of inorganic base plays a key role in the degradation efficiency of PFOA in the photochemical reaction system. Within the preferred alkali concentration range of the present invention, significant degradation and defluorination capabilities are shown. In Example 6, as the NaOH concentration increases from 0.01mmol to 0.1mmol, the degradation rate of PFOA within 24h is increased from 93.0% to 99.9%, and the defluorination rate increases synchronously, showing an excellent mineralization effect. On the contrary, when the NaOH concentration in Comparative Example 7 is too low (0.005mmol), the PFOA degradation rate and defluorination rate decrease significantly, indicating that in the absence of sufficient alkaline conditions, the metal-ligand complex cannot be effectively formed, the reaction is hindered, and the degradation efficiency is limited. When an inorganic base is added at an excessively high concentration, the degradation rate and defluorination rate do not increase but decrease. This is because the concentration of the base is too high, a blue precipitate will be produced, which reduces the active Cu in the solution. 2+ Therefore, an appropriate amount of inorganic base is not only a prerequisite for initiating the LMCT process, but also a key factor in ensuring the efficient operation of the PFAS degradation system. The inorganic base concentration range determined in this invention (0.05–0.1 mmol) can effectively balance deprotonation, complexation ability, and reaction kinetics, providing stable and controllable reaction conditions for subsequent photochemical reactions.

[0076] The degradation process of PFOA in Example 1 is as follows Figure 1 As shown in the figure, PFOA undergoes continuous degradation in the reaction system, and a variety of short-chain perfluorocarboxylic acid intermediates are gradually generated during the process. Their concentrations first increase and then decrease over time, and eventually tend to disappear, indicating that they are further transformed or mineralized as transition products. The fluorine mass balance results show that F - The concentration of short-chain perfluorocarboxylic acids, the primary end product of PFOA degradation, continues to rise with reaction time. Short-chain perfluorocarboxylic acids reach a peak in the middle of the reaction time and then rapidly decline. As illumination time increases, the total mass of fluorine in the system gradually approaches the theoretical value and stabilizes, indicating that the intermediates and end products generated during the degradation process have been essentially completely converted and captured. This phenomenon demonstrates that this method can achieve deep degradation and efficient mineralization of PFOA, offering advantages such as controllable intermediates, few byproducts, and high conversion efficiency. It holds significant practical application value and potential for widespread adoption in the field of PFAS treatment.

[0077] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. A method for photochemically driven efficient degradation of PFAS, characterized in that: The steps include: S1: Preparation of reaction solution: Add transition metal salt ions and inorganic base to the eluent containing PFAS and stir evenly to form [transition metal salt ions-PFAS] + complex reaction solution; S2: Add the above reaction solution into a quartz container, and start and carry out the PFAS degradation reaction under the irradiation of a light source in the wavelength range of 220-455nm.

2. The method for photochemically driven efficient degradation of PFAS according to claim 1, characterized in that: In step S1, the transition metal salt ions include one or more of copper salts, iron salts or cerium salts.

3. The method for photochemically driven efficient degradation of PFAS according to claim 2, characterized in that: The copper salt is a divalent copper salt, the iron salt is a trivalent iron salt, and the cerium salt is a trivalent cerium salt.

4. The method for photochemically driven efficient degradation of PFAS according to claim 3, characterized in that: The divalent copper salt includes one or more selected from copper trifluoromethanesulfonate (Cu(OTf)2) or copper tetrafluoroborate (Cu(BF4)2); The trivalent iron salt is selected from one or more of iron trifluoromethanesulfonate (Fe[OTf]3) or ferric chloride (FeCl3); The trivalent cerium salt is selected from one or both of cerium trifluoromethanesulfonate (Ce[OTf]3) and cerium chloride (CeCl3).

5. The method for photochemically driven efficient degradation of PFAS according to claim 1, characterized in that: In step S1, the inorganic base is selected from one or more of sodium hydroxide (NaOH), potassium hydroxide (KOH) or ammonia water (NH4OH).

6. The method for photochemically driven efficient degradation of PFAS according to any one of claims 1 to 5, characterized in that: In step S1, PFAS is a perfluoroalkyl carboxylic acid or perfluoroether carboxylic acid compound having a carbon chain length of 2-12.

7. The method for photochemically driven efficient degradation of PFAS according to any one of claims 1 to 5, characterized in that: In step S1, the molar ratio of the transition metal salt ion to PFAS is 0.1:1 to 2:1, and the molar ratio of the inorganic base to PFAS is 0.1:1 to 1:

1.

8. The method for photochemically driven efficient degradation of PFAS according to any one of claims 1 to 5, characterized in that: In step S1, the PFAS concentration is 0.01 mM to 50 mM.

9. The method for photochemically driven efficient degradation of PFAS according to any one of claims 1 to 5, characterized in that: In step S1, the eluent is selected from acetonitrile (MeCN), dimethylformamide (DMF) or methanol (MeOH); in step S2, the reaction time is 24h-48h, and the light source includes a high-pressure mercury lamp, a xenon lamp, an LED lamp or a solar simulator.

10. Use of the method for photochemically driven efficient degradation of PFAS according to any one of claims 1 to 9 in the degradation of PFAS.

Images