A method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles.

Abstract

The application relates to a method for degrading organic pollutants by using a cobalt intercalated 1T-MoS2 cathode and micro-nano bubbles, and relates to a method for degrading organic pollutants by using a 1T-MoS2 cathode and bubbles. The application aims to solve the technical problems of poor conductivity of a cathode molybdenum disulfide layered transition metal sulfide in current AOPs, limited active sites at edges, poor ORR selectivity and insufficient H2O2 activation capacity. The application first synthesizes cobalt intercalated 1T-MoS2 by using a one-step plasma treatment technology, and the cobalt atoms are uniformly distributed in the MoS2 layers in the form of intercalation. The application also introduces a micro-nano bubble technology, which greatly improves the dissolved oxygen concentration and mass transfer efficiency in water. Through the synergistic effect of the three-in-one combination of "material innovation-mass transfer enhancement-in-situ activation", the application realizes efficient, rapid and deep degradation of organic pollutants under mild electrochemical conditions.

Description

Technical Field

[0001] This invention relates to a method for the synergistic degradation of organic pollutants using a 1T-MoS2 cathode and air bubbles. Background Technology

[0002] With rapid industrialization and urbanization, the deep removal of organic pollutants (such as persistent organic pollutants, endocrine disruptors, and antibiotics) from water bodies has become a major challenge in the environmental field. Traditional biological and physical methods are insufficient to completely mineralize these toxic and harmful substances, while advanced oxidation technologies (AOPs) have attracted much attention due to their ability to generate highly oxidizing ·OH.

[0003] Among numerous AOPs (Alternative Organic Wastewater Treatments), electro-Fenton technology is considered a highly promising technology for organic wastewater treatment due to its advantages such as in-situ H2O2 production, controllable operation, and environmental friendliness. However, traditional electro-Fenton technology still faces the following key bottlenecks:

[0004] 1. Strict pH restrictions: Traditional homogeneous electro-Fenton ...

[0005] 2. Low mass transfer efficiency: Oxygen has extremely low solubility in water (about 8-9 mg / L), which limits the yield of H2O2 and makes it the rate-limiting step of the entire reaction; ordinary aeration produces large bubbles with short residence time, resulting in low oxygen utilization.

[0006] 3. Low activation efficiency of H2O2: Even if H2O2 is generated, it is absorbed by catalysts (such as Fe). 2+ The efficiency of effective cracking to produce ·OH is also limited, and side reactions are prone to occur, leading to waste of oxidant;

[0007] 4. Insufficient performance of cathode materials: Traditional carbon-based cathodes (such as graphite and carbon felt) have low selectivity and activity for oxygen reduction reaction (ORR) to generate H2O2, and lack the ability to activate H2O2 in situ.

[0008] Layered transition metal sulfides such as molybdenum disulfide have shown potential in electrocatalysis due to their tunable electronic structure and catalytic activity. However, the natural 2H phase MoS2 exhibits poor conductivity and its active sites are confined to the edges. Although constructing a 1T metal phase can improve conductivity, further regulating its ORR selectivity and endowing it with H2O2 activation ability remains a challenge. Summary of the Invention

[0009] This invention aims to address the technical problems of poor conductivity, limited active sites, poor ORR selectivity, and insufficient H2O2 activation capacity of molybdenum disulfide layered transition metal sulfides in current AOPs cathodes, and provides a method for the synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles.

[0010] The method of the present invention for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles is carried out according to the following steps:

[0011] I. Precursor Preparation: Dissolve the molybdenum source and sulfur source together in deionized water and stir to form a homogeneous solution; then add the cobalt source to the mixture and sonicate to ensure Co content is within acceptable limits. 2+ The ions are uniformly dispersed; then the mixed solution is freeze-dried to obtain the precursor powder.

[0012] II. Plasma Treatment: The precursor powder obtained above is evenly spread in a quartz boat and placed in the center of the reaction chamber of a radio frequency plasma-enhanced chemical vapor deposition (PECVD) system; the chamber is evacuated; then argon gas is introduced as a protective gas; the radio frequency power supply is turned on, and the precursor powder is bombarded with Ar plasma; the plasma power supply is turned off, and the mixture is allowed to cool naturally to room temperature under the protection of the Ar atmosphere. The black powder collected is Co. x -1T-MoS2, where x represents the molar ratio of Co to Mo as x:1;

[0013] The high-energy environment of plasma can simultaneously achieve Mo 6+ The reduction, doping of S atoms, intercalation of Co atoms, and transformation of the 2H phase to the 1T metallic phase;

[0014] III. Electrode Preparation: The Co prepared above... x -1T-MoS2 powder, conductive carbon, and polyvinylidene fluoride were mixed to obtain a slurry; N-methyl-2-pyrrolidone was added dropwise until the slurry was fluid, glossy, and pasty, and then ground into a uniform slurry; the slurry was uniformly coated onto a carbon felt and then vacuum dried to obtain Co. x -1T-MoS2 cathode;

[0015] IV. System Setup: A two-electrode electrolytic cell with a proton exchange membrane as the diaphragm was constructed, using the Co prepared above. x -1T-MoS2 cathode is used as cathode, and platinum sheet or carbon electrode is used as anode; add the aqueous solution containing organic pollutants to be treated to the electrolytic cell, and then add Na2SO4 as supporting electrolyte;

[0016] V. Electrochemical Degradation of Pollutants: Micro- and nano-oxygen bubbles generated by a nanobubble generator are continuously introduced into the bottom of the entire electrolysis cell. These micro- and nano-bubbles are a group of bubbles composed of micron-sized bubbles with a particle size of 10μm to 50μm and nano-sized bubbles with a particle size of less than 200nm. These micro- and nano-bubbles have extremely high specific surface area and residence time, significantly increasing the dissolved oxygen concentration in the water to 40mg / L to 50mg / L (far higher than the 9mg / L of ordinary aeration). Then, a voltage is applied while simultaneously continuing to introduce micro- and nano-oxygen bubbles. Due to the high CO2 content... x The -1T-MoS2 cathode surface exhibits excellent two-electron oxygen reduction reaction (2e - The ORR pathway is selective, and dissolved oxygen is reduced on the cathode surface, generating a large amount of H2O2 in situ. Micro- and nano-bubbles can generate local high pressure and interfacial charge effects upon rupture. These bubbles collide and interact violently with the H2O2 generated in situ on the cathode surface, weakening the OH-OH bonds of H2O2 and further inducing the cracking reaction of H2O2, generating a large number of highly active hydroxyl radicals (·OH). The generated strong oxidizing ·OH (oxidation potential as high as 2.8V) non-selectively attacks organic pollutant molecules in the water, effectively mineralizing them into non-toxic products such as CO2 and H2O.

[0017] This invention proposes a novel synergistic strategy: First, using 1T phase molybdenum disulfide as a matrix, a cobalt (Co)-intercalated 1T-MoS2 is synthesized in a one-step process via plasma processing technology. Co (Co) atoms are uniformly distributed in the intercalation form between the MoS2 layers. The Co intercalation not only stabilizes the 1T metallic phase and improves conductivity, but more importantly, Co... 3+ / Co 2+ The variable valence property of the material can serve as a key species driving H2O2 activation; secondly, this invention innovatively introduces micro-nano bubble technology, which greatly improves the dissolved oxygen concentration and mass transfer efficiency in water, solving the problem of low H2O2 yield from the source; more ingeniously, the instantaneous charge energy generated when the micro-nano bubbles burst can synergistically promote the decomposition of H2O2. Through the synergistic effect of "material innovation-mass transfer enhancement-in-situ activation", this invention achieves efficient, rapid and deep degradation of organic pollutants under mild electrochemical conditions.

[0018] The primary objective of this invention is to overcome the bottlenecks of existing electro-Fenton technology in treating organic wastewater, such as low H2O2 yield, poor activation efficiency, dependence on external energy input (light / electricity), and narrow pH adaptation range. The invention aims to provide a novel material, system, and method for the deep removal of organic pollutants that can operate under neutral conditions (electrolyte) without the need for external light / electricity.

[0019] Compared with existing technologies, the Co-intercalated 1T-MoS2 cathode and its synergistic method with nanobubbles provided by this invention exhibit the following advantages:

[0020] 1. Ultrafast degradation kinetics and high efficiency: The degradation rate of various organic pollutants exceeds 90% within 60 minutes, with the best reaching 98.5%. Moreover, its reaction rate constant is more than 5 times that of traditional carbon-based electrodes and several times that of traditional electro-Fenton systems.

[0021] 2. Overcoming pH limitations: This invention exhibits optimal performance under neutral (sodium sulfate) conditions, eliminating the need to pre-adjust wastewater to acidity and avoiding the subsequent treatment costs and secondary pollution risks associated with acid-base neutralization.

[0022] 3. Synergistic Mechanism Innovation: This invention is the first to combine "intercalated materials with high selectivity for H2O2 production" with "high mass transfer / high energy micro / nano bubbles". By utilizing the dual mechanisms of "H2O2 homolytic cracking induced by nano bubble rupture energy" and "H2O2 heterogeneous catalytic cracking induced by Co species", the ultra-efficient generation of ·OH is achieved, which is an effect that cannot be achieved by a single technical route.

[0023] 4. Simple and efficient material synthesis: This invention achieves phase transformation (2H→1T), heteroatomation (Co), defect construction (S vacancy) and material synthesis simultaneously through a one-step plasma treatment method. The process is simple, fast, and environmentally friendly, and the resulting material has a stable structure and abundant active sites.

[0024] The breakthrough technical effects achieved by this invention stem from multi-level collaborative innovation, ranging from the microstructure of materials to the design of macroscopic reactors:

[0025] At the materials level (atomic-level design): Co atoms were inserted into the interlayer of MoS2 using a plasma method, achieving triple functional integration.

[0026] Firstly, phase transition and conductivity: stabilizing the metallic 1T phase ensures rapid electron transport;

[0027] Second, selective catalysis: the electronic structure of MoS2 was precisely controlled, causing its ORR pathway to change from 4e... - The generated water is converted into 2e⁻ to form H₂O₂, with a selectivity of up to 95%.

[0028] Thirdly, in-situ activation: the intercalated Co itself is a highly efficient Fenton-like catalyst, capable of being activated by Co... 3+ / Co 2+ The variable valence cycle provides additional electrons, which in-situ cleave the H2O2 generated on its own surface, shortening the diffusion distance of active species.

[0029] Mass transfer level (micro / nano bubble enhancement): Micro / nano bubbles increase the dissolved oxygen concentration in water to a supersaturated state (>40 mg / L), fundamentally solving the problem of limited oxygen mass transfer in electro-Fenton technology. Simultaneously, their extremely high specific surface area and residence time provide ample reaction interface for cathode ORR.

[0030] Activation level (physical-chemical synergy): The local high temperature and pressure (thousands of K, hundreds of atmospheres) and interfacial free radical effect generated when nanobubbles rupture provide additional energy for the homolytic cracking of H2O2. This is equivalent to an "energy injector" on a microscale, which significantly reduces the energy barrier for H2O2 activation and perfectly complements the catalytic effect of Co.

[0031] In summary, this invention, through a clever "material-bubble" synergistic strategy, successfully overcomes the problems of high energy consumption and low efficiency in traditional AOPs technology, opening up a new path for green, low-carbon, and efficient deep water treatment technology. Attached Figure Description

[0032] Figure 1 Co prepared for step two of experiment two 0.1 SEM image of -1T-MoS2;

[0033] Figure 2 Raman spectrum;

[0034] Figure 3 XRD pattern;

[0035] Figure 4 A comparison chart showing the efficiency of degrading sulfamethoxazole in different reaction systems;

[0036] Figure 5 This is a graph showing the data from the broad-spectrum test in Experiment 6;

[0037] Figure 6 This is a graph showing the data from the stability test in Experiment 6. Detailed Implementation

[0038] Specific Implementation Method 1: This implementation method is a method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles, specifically carried out according to the following steps:

[0039] I. Precursor Preparation: Dissolve the molybdenum source and sulfur source together in deionized water and stir to form a homogeneous solution; then add the cobalt source to the mixture and sonicate to ensure Co content is within acceptable limits. 2+ The ions are uniformly dispersed; then the mixed solution is freeze-dried to obtain the precursor powder.

[0040] II. Plasma Treatment: The precursor powder obtained above is evenly spread in a quartz boat and placed in the center of the reaction chamber of the radio frequency plasma-enhanced chemical vapor deposition system; the chamber is evacuated; then argon gas is introduced as a protective gas; the radio frequency power supply is turned on, and the precursor powder is bombarded with Ar plasma; the plasma power supply is turned off, and the powder is allowed to cool naturally to room temperature under the Ar atmosphere, collecting the black powder, which is Co. x -1T-MoS2, where x represents the molar ratio of Co to Mo as x:1;

[0041] III. Electrode Preparation: The Co prepared above... x -1T-MoS2 powder, conductive carbon, and polyvinylidene fluoride were mixed to obtain a slurry; N-methyl-2-pyrrolidone was added dropwise until the slurry was fluid, glossy, and pasty, and then ground into a uniform slurry; the slurry was uniformly coated onto a carbon felt and then vacuum dried to obtain Co. x -1T-MoS2 cathode;

[0042] IV. System Setup: A two-electrode electrolytic cell with a proton exchange membrane as the diaphragm was constructed, using the Co prepared above. x -1T-MoS2 cathode is used as cathode, and platinum sheet or carbon electrode is used as anode; add the aqueous solution containing organic pollutants to be treated to the electrolytic cell, and then add Na2SO4 as supporting electrolyte;

[0043] V. Electrochemical Degradation of Pollutants: Micro- and nano-oxygen bubbles generated by a nano-bubble generator are continuously introduced into the bottom of the entire electrolytic cell. The micro- and nano-bubbles are a group of bubbles composed of micron bubbles with a particle size of 10μm to 50μm and nano bubbles with a particle size of less than 200nm. When the dissolved oxygen concentration in the water rises to 40mg / L to 50mg / L, a voltage is applied while micro- and nano-oxygen bubbles are continuously introduced to degrade organic pollutant molecules and effectively mineralize them into CO2 and H2O.

[0044] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the molybdenum source mentioned in step one is (NH4)5Mo7O. 24 The sulfur source is C2H5NS, and the molar ratio of Mo to S is 1:3. Everything else is the same as in Specific Embodiment 1.

[0045] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the cobalt source mentioned in step one is Co(NO3)2·6H2O, and the molar ratio of Co to Mo is (0.05~0.2):1. Everything else is the same as in Specific Implementation Method 2.

[0046] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: in step two, the cavity is evacuated to a base pressure <3Pa; then, argon gas is introduced as a protective gas until the cavity pressure reaches 50Pa. Everything else is the same as in Specific Implementation Methods One to Three.

[0047] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method Four in that: in step two, the radio frequency power supply is turned on and the power is set to 300W~500W. The precursor powder is bombarded with Ar plasma for 30min~60min. Everything else is the same as in Specific Implementation Method Four.

[0048] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Five in that the conductive carbon mentioned in step three is Super P, and Co... x The mass ratio of -1T-MoS2 powder, conductive carbon, and polyvinylidene fluoride is 7:2:1; the vacuum drying conditions in step three are: vacuum drying at 60°C for 12 hours. Other conditions are the same as in specific implementation method five.

[0049] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that: the organic pollutant mentioned in step four is sulfamethoxazole, tetracycline, or florfenicol, and its concentration is 20 mg / L; the concentration of Na2SO4 after being added to the electrolytic cell is 0.05 M. Everything else is the same as in Specific Implementation Method Six.

[0050] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Seven in that the voltage applied in step five is in the range of -0.8 to -1.2V. Everything else is the same as in Specific Implementation Method Seven.

[0051] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Eight in that the proportion of nanobubbles with a particle size of less than 200 nm in the micro-nanobubbles described in step five is 40% to 45%. Everything else is the same as in Specific Implementation Method Eight.

[0052] The invention was verified using the following experiments:

[0053] Experiment 1: This experiment demonstrates a method for the synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles. The specific steps are as follows:

[0054] I. Precursor preparation: (NH4)5Mo7O 24 • 4H2O and C2H5NS were dissolved together in deionized water and stirred to form a homogeneous solution; then Co(NO3)2·6H2O was added to the mixture, and the mixture was sonicated for 30 min to ensure that Co 2+ The ions are uniformly dispersed; then the mixed solution is freeze-dried to obtain the precursor powder.

[0055] The molar ratio of Mo to S is 1:3, and the molar ratio of Co to Mo is 0.05:1.

[0056] II. Plasma Treatment: The precursor powder obtained above is evenly spread in a quartz boat and placed in the center of the reaction chamber of the radio frequency plasma enhanced chemical vapor deposition system; the chamber is evacuated to a base pressure <3 Pa; then, argon gas is introduced as a protective gas until the chamber pressure reaches 50 Pa; the radio frequency power supply is turned on at a power of 500 W, and the process is carried out for 30 min, using Ar plasma to bombard the precursor powder; the plasma power supply is turned off, and the mixture is allowed to cool naturally to room temperature under the protection of the Ar atmosphere. The black powder collected is Co. 0.05 -1T-MoS2;

[0057] III. Electrode Preparation: The Co prepared above... 0.05 -1T-MoS2 powder, conductive carbon Super P, and polyvinylidene fluoride were mixed at a mass ratio of 7:2:1 to obtain a slurry; N-methyl-2-pyrrolidone was added dropwise until the slurry was fluid, glossy, and pasty, and then ground into a uniform slurry; the slurry was then uniformly coated onto a carbon felt (3cm×4cm) with a loading of 2mg / cm². 2 Then, vacuum drying is performed to obtain Co. 0.05 -1T-MoS2 cathode;

[0058] The conditions for vacuum drying are: vacuum drying at 60℃ for 12 hours;

[0059] IV. System Setup: A two-electrode electrolytic cell with a proton exchange membrane as the diaphragm was constructed, using the Co prepared above. 0.05 -1T-MoS2 cathode is used as cathode, platinum sheet is used as anode, and the distance between the two electrodes is 1cm; 50mL of aqueous solution containing organic pollutants to be treated is added to the electrolytic cell, and then Na2SO4 is added as supporting electrolyte;

[0060] The organic pollutant is sulfamethoxazole, tetracycline, or florfenicol, and the concentration is 20 mg / L; the concentration of Na2SO4 after being added to the electrolytic cell is 0.05 M.

[0061] V. Electrochemical Degradation of Pollutants: Micro- and nano-oxygen bubbles generated by a nano-bubble generator are continuously introduced into the bottom of the entire electrolysis cell through an aeration disc at the bottom of the reactor. The micro- and nano-bubbles are a group of bubbles composed of micron bubbles with a particle size of 10μm to 50μm and nano bubbles with a particle size of less than 200nm, and the number of nano bubbles with a particle size of less than 200nm accounts for 45% of the micro- and nano-bubbles. When the dissolved oxygen concentration in the water rises to 50mg / L, a voltage of -1.2V is applied while micro- and nano-oxygen bubbles are continuously introduced to degrade organic pollutant molecules and effectively mineralize them into CO2 and H2O. 1mL of sample is taken every 10 minutes, filtered, and the concentration of residual organic matter is analyzed by high performance liquid chromatography (HPLC) to calculate the degradation rate.

[0062] Experiment Two: This experiment differs from Experiment One in that the molar ratio of Co to Mo in Step One is 0.1:1; and the black powder collected in Step Two is Co. 0.1 -1T-MoS2; Step 3 yields Co 0.1 -1T-MoS2 cathode. Everything else is the same as in Experiment 1.

[0063] Experiment 3: This experiment differs from Experiment 1 in that the molar ratio of Co to Mo in step 1 is 0.2:1; and the black powder collected in step 2 is Co. 0.2 -1T-MoS2; Step 3 yields Co 0.2 -1T-MoS2 cathode. Everything else is the same as in Experiment 1.

[0064] Figure 1 Co prepared for step two of experiment two 0.1 The SEM image of -1T-MoS2 shows that Co 0.1 -1T-MoS2 mainly exists in an aggregated state.

[0065] Figure 2 The images show the Raman spectra of Co prepared in experiments one through three. 0.05 -1T-MoS2, Co 0.1 -1T-MoS2 and Co 0.2 The presence of characteristic peaks J1, J2, and J3 in -1T-MoS2, conventional 1T-MoS2, and 2H-MoS2 confirms the existence of the 1T phase.

[0066] Figure 3 The images show the XRD patterns of Co prepared in experiments one through three. 0.05 -1T-MoS2, Co 0.1 -1T-MoS2 and Co 0.2 -1T-MoS2 and conventional 1T-MoS2 show that Co xThe (002) peak of -1T-MoS2 (x=0.2 / 0.1 / 0.05) is shifted compared to the conventional 1T-MoS2, confirming that Co was successfully inserted into the interlayer of MoS2, and the interlayer spacing of 1T-MoS2 expands as the amount of Co insertion increases.

[0067] Comparative Experiment 1: The difference between this experiment and Experiment 1 is that Co(NO3)2·6H2O is not added in step 1, i.e., Co is not doped; the powder collected in step 2 is 1T-MoS2; and the 1T-MoS2 cathode is obtained in step 3. Everything else is the same as Experiment 1.

[0068] Experiment 4: Evaluation of ORR (Oriented Return) and H2O2 Production Performance of 1T-MoS2 Cathodes with Different Co Doping Amounts: Using the cathodes obtained in the above four experiments, their ORR performance was tested in 0.1M KOH solution using a rotating disk electrode (RDE) at a rotation speed of 1600 rpm and a scan rate of 10 mV / s. The electron transfer number (n) and H2O2 selectivity (%) were calculated. Results: The Koutecky-Levich equation results calculated by the rotating disk electrode (RDE) show that the electron transfer number (n) of the 1T-MoS2 cathode is approximately 3.52, indicating that its ORR is mainly via the 4-electron pathway (water production). Meanwhile, the Co-intercalated Co... 0.1 The -1T-MoS2 cathode has the lowest n value (approximately 2.08), indicating that it can efficiently promote the 2e-phase reduction of ORR. - This process generates a large amount of H2O2.

[0069] Experiment 5: Using Co from Experiment 2 0.1 The sulfamethoxazole degradation experiment at the -1T-MoS2 cathode is described in steps four and five of Experiment 2.

[0070] Comparative Experiment 2: This experiment differs from Experiment 5 in that the cathode is a blank carbon felt cathode. Everything else is the same as Experiment 5.

[0071] Comparative Experiment 3: This experiment differs from Experiment 5 in that, instead of introducing micro-nano oxygen bubbles in step 5, ordinary oxygen with a particle size of 0.4cm~0.6cm is introduced. Everything else is the same as Experiment 5.

[0072] Figure 4The figures show a comparison of the degradation efficiency of sulfamethoxazole in different reaction systems. Figure (a) shows the concentration of sulfamethoxazole over time, and Figure (b) shows the pseudo-first-order reaction kinetics curve. The pink line represents comparative experiment two, the orange line represents comparative experiment three, and the blue line represents experiment five. The results show that only by coupling the Co-1T-MoS2 cathode with nano-oxygen bubble technology can ultra-fast and efficient degradation of organic pollutants be achieved. This proves that the "material-bubble" synergistic mechanism of this invention is not a simple functional superposition, but rather produces a significant synergistic effect.

[0073] Experiment Six: This experiment is for Co 0.1 The broad spectrum and cycle stability of the -1T-MoS2 cathode were tested, and the specific process is described in Experiment 2.

[0074] Broad-spectrum testing: Tetracycline, florfenicol, and sulfamethoxazole were used as target pollutants at concentrations of 20 mg / L. Figure 5 The results showed that the degradation rates of tetracycline, florfenicol, and sulfamethoxazole solutions all reached 100% within 60 minutes, demonstrating that the system has excellent deep removal capabilities for various organic pollutants with different structures and proving its great application potential in the treatment of complex wastewater.

[0075] Stability testing: using Co 0.1 The sulfamethoxazole was subjected to five consecutive cyclic degradation experiments using a 1T-MoS2 cathode (each cycle lasting 60 minutes, after which the electrode was rinsed with deionized water). Figure 6 The results show that after five cycles of use, the material still maintains extremely high activity. (Co) 0.1 The degradation rate of sulfamethoxazole by the -1T-MoS2 electrode remains above 99.9%, indicating its excellent stability. The robust structure brought about by plasma treatment and the firm intercalation of Co are the fundamental guarantees of stability.

[0076] Comparative Experiment 4: Co prepared by the traditional hydrothermal method 0.1 Using 1T-MoS2 as the cathode and ammonium molybdate tetrahydrate and thiourea as the molybdenum and sulfur sources, respectively, a simple hydrothermal method (200℃, 24h) was used to prepare 2H-MoS2 material. The material is predominantly 2H phase, with a 1T phase content of less than 20%. Its ORR electron transfer number (n) is 3.1, and its H2O2 selectivity is only 45%. In degradation tests, the degradation rate of sulfamethoxazole was only 60% after 60 minutes, far lower than the 98.5% achieved by the plasma-based cathode of this invention. This comparative experiment demonstrates the superiority of the key process feature of this invention: the "plasma treatment method." Only through the high-energy environment of plasma can high-concentration Co intercalation and a high content of the 1T phase stably coexist, which is difficult to achieve using traditional thermochemical methods, directly determining the ORR pathway selectivity and catalytic activity of the material.

[0077] Comparative Experiment 5: Using Co prepared in Experiment 2 0.1 -1T-MoS2 cathode, but no air bubbles are introduced to degrade sulfamethoxazole, other conditions are the same as in Experiment 2.

[0078] Comparison results:

[0079] Despite the application of an external voltage, the degradation rate of sulfamethoxazole was only 75% after 60 minutes due to the low dissolved oxygen concentration (~8 mg / L). In Experiment 2, the addition of a nanobubble system resulted in a degradation rate of 98.5%, higher than 75%. This comparative experiment demonstrates that "nanobubbles" are not simply a substitute for aeration; they not only overcome the mass transfer limitations of the reactants (O2) but also synergistically participate in the formation of ·OH.

Claims

1. A method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles, characterized in that... The method is performed according to the following steps: I. Precursor Preparation: Dissolve the molybdenum source and sulfur source together in deionized water and stir to form a homogeneous solution; then add the cobalt source to the mixture and sonicate to ensure Co content is within acceptable limits. 2+ Ions are uniformly dispersed; The mixed solution was then freeze-dried to obtain the precursor powder; II. Plasma Treatment: The precursor powder obtained above is evenly spread in a quartz boat and placed in the center of the reaction chamber of the radio frequency plasma-enhanced chemical vapor deposition system; the chamber is evacuated; then argon gas is introduced as a protective gas; the radio frequency power supply is turned on, and the precursor powder is bombarded with Ar plasma; the plasma power supply is turned off, and the mixture is allowed to cool naturally to room temperature under the Ar atmosphere, and the black powder is collected as Co. x -1T-MoS2, where x represents the molar ratio of Co to Mo as x:1; III. Electrode Preparation: The Co prepared above... x -1T-MoS2 powder, conductive carbon, and polyvinylidene fluoride were mixed to obtain a slurry; N-methyl-2-pyrrolidone was added dropwise until the slurry was fluid, glossy, and pasty, and then ground into a uniform slurry; the slurry was uniformly coated onto a carbon felt and then vacuum dried to obtain Co. x -1T-MoS2 cathode; IV. System Setup: A two-electrode electrolytic cell with a proton exchange membrane as the diaphragm was constructed, using the Co prepared above. x -1T-MoS2 cathode is used as cathode, and platinum sheet or carbon electrode is used as anode; add the aqueous solution containing organic pollutants to be treated to the electrolytic cell, and then add Na2SO4 as supporting electrolyte; V. Electrochemical Degradation of Pollutants: Micro- and nano-oxygen bubbles generated by a nano-bubble generator are continuously introduced into the bottom of the entire electrolytic cell. The micro- and nano-bubbles are a group of bubbles composed of micron bubbles with a particle size of 10μm to 50μm and nano bubbles with a particle size of less than 200nm. When the dissolved oxygen concentration in the water rises to 40mg / L to 50mg / L, a voltage is applied while micro- and nano-oxygen bubbles are continuously introduced to degrade organic pollutant molecules and effectively mineralize them into CO2 and H2O.

2. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 1, characterized in that... The molybdenum source mentioned in step one is (NH4)5Mo7O 24 ·4H2O, the sulfur source is C2H5NS, and the molar ratio of Mo to S is 1:

3.

3. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 2, characterized in that... The cobalt source mentioned in step one is Co(NO3)2·6H2O, and the molar ratio of Co to Mo is (0.05~0.2):

1.

4. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 1, characterized in that... In step two, the cavity is evacuated to a base pressure of <3Pa; then, argon gas is introduced as a protective gas until the cavity pressure reaches 50Pa.

5. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 4, characterized in that... In step two, turn on the radio frequency power supply and set the power to 300W~500W. Use Ar plasma to bombard the precursor powder for 30min~60min.

6. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 1, characterized in that... The conductive carbon mentioned in step three is Super P, and Co x The mass ratio of -1T-MoS2 powder, conductive carbon, and polyvinylidene fluoride is 7:2:1; the vacuum drying conditions in step three are: vacuum drying at 60℃ for 12 hours.

7. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 1, characterized in that... The organic pollutant mentioned in step four is sulfamethoxazole, tetracycline or florfenicol, and the concentration is 20 mg / L; the concentration of Na2SO4 after being added to the electrolytic cell is 0.05 M.

8. The method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 1, characterized in that... The voltage applied in step five is in the range of -0.8 to -1.2V.

9. A method for synergistic degradation of organic pollutants using a cobalt-intercalated 1T-MoS2 cathode and micro / nano bubbles according to claim 1, characterized in that... In step five, the proportion of nanobubbles with a particle size of less than 200 nm in the micro-nanobubbles is 40% to 45%.

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