Photo-activated persulfate catalytic materials, their preparation methods, and applications.

Abstract

This invention discloses a photo-regulated activated persulfate catalytic material, its preparation method, and its application, belonging to the field of catalytic material technology. The catalytic material is MoSe2 / Mo2CT. x The Schottky heterojunction structure is constructed using the following method: Mo2CT x Using Mo2CT as the substrate material, interface engineering and in-situ growth strategies were employed. x MoSe2 is grown in situ on the substrate surface to construct MoSe2 / Mo2CT. x Schottky heterojunction; this structure significantly improves the specific surface area and number of active sites of the material, effectively broadens the light absorption range, enhances photothermal conversion capability, and realizes rapid and directional migration of photogenerated carriers; at the same time, when applied to the photocatalytic-photothermal synergistic activation PMS system, the system has dual-channel characteristics of "visible light response" and "photothermal response", so that the ROS can be directionally regulated through external light source mode.

Description

Technical Field

[0001] This invention relates to the field of catalytic materials technology, specifically a catalytic material based on photo-regulated activation of persulfate, its preparation method, and its application. Background Technology

[0002] With the increasing discharge of wastewater from fine chemicals, plastics products, metal processing, and urban domestic sewage, emerging organic pollutants in water bodies tend to persist for a long time due to their stable structure, poor biodegradability, and high mobility. Phenolic pollutants, represented by bisphenol A (BPA), pose a long-term potential threat to ecosystems and human health. Currently, BPA removal technologies in water bodies mainly include physical adsorption, biodegradation, and advanced oxidation processes. However, methods such as physical adsorption only achieve phase transfer of pollutants and do not fundamentally decompose them. Furthermore, they suffer from difficulties in adsorbent regeneration or the generation of concentrated solutions requiring secondary treatment. Therefore, developing green purification technologies that can efficiently and thoroughly degrade and mineralize BPA has become an important research direction in the fields of environmental engineering and catalysis science.

[0003] Advanced oxidation processes (AOPs) can generate highly reactive oxidizing species in situ, capable of disrupting molecular structures and achieving transformation, and are therefore considered closer to a pathway for "pollution elimination." Among them, persulfate-based advanced oxidation technologies (SR-AOPs) utilize persulfate (PMS) which can be activated by heat, light, metal / carbon materials, electrochemistry, and other methods, and can generate various reactive oxygen species (ROS, such as SO42-). - •OH 1 O2 and O2• - ), has received attention in the treatment of recalcitrant organic matter.

[0004] However, a key bottleneck faced by SR-AOPs in practical wastewater treatment is the difficulty in controlling the type and ratio of ROS, making it difficult to balance efficiency, selectivity, and stability. Different ROS exhibit significant differences in oxidation capacity, reaction selectivity, and resistance to matrix interference: sulfate radicals (SO4•) - It typically has strong oxidizing power and is suitable for broad-spectrum degradation and mineralization, but is susceptible to Cl. - HCO3 - / CO3 2- Competition and transformation of natural organic matter and other substances reduce the effective utilization rate; singlet oxygen 1O2 exhibits certain selective oxidation advantages and is relatively less affected by free radical capture in some complex matrices. However, it is often difficult to generate stably and at high throughput in conventional PMS systems, and its generation mechanism is strongly constrained by the electronic structure of the catalytic interface and the energy / electron transfer pathway. Because existing systems prioritize overall removal rate improvement rather than "outputting specific ROS on demand," they often encounter problems such as significant differences in treatment effects and unstable mineralization levels under the same process conditions when dealing with different pollutants or different water quality backgrounds.

[0005] For PMS activation methods, thermal activation suffers from engineering limitations such as high energy consumption and complex thermal management; while single photocatalysis can utilize solar energy, traditional semiconductors generally suffer from narrow spectral response, severe carrier recombination, and low quantum efficiency, resulting in limited activation rate and stability; transition metal catalytic systems may bring secondary pollution risks such as metal dissolution and recovery difficulties; carbon material systems may also undergo structural evolution and activity decay under strong oxidizing environments or long-term operation. Overall, the challenge of existing technologies has shifted from "whether ROS can be generated" to "whether the target ROS can be generated directionally and suppressed under mild, low-side-effect conditions."

[0006] Against this backdrop, photothermal catalysis, as a strategy that converts light energy into localized heat energy and couples it with surface catalytic reactions, offers a novel approach for PMS activation. The photothermal effect can achieve localized heating of the catalytic interface without significantly increasing the overall system temperature, kinetically lowering the activation energy barrier, accelerating electron transfer and adsorption-desorption processes, and potentially altering the activation pathway of PMS on the catalytic surface, thereby affecting the composition of ROS formation. Compared to single photocatalysis, photothermal coupling holds promise for simultaneously utilizing "photocharge-driven interfacial reactions" and "reaction kinetics enhanced by localized temperature rise," achieving higher energy utilization efficiency under sunlight conditions. However, existing photothermal materials also suffer from insufficient stability and controllability: while plasmonic metal nanomaterials possess broad-spectrum absorption capabilities, they are prone to aggregation, morphological reconstruction, or corrosion and oxidation; some carbon-based photothermal materials may be gradually oxidized in strongly oxidizing environments; and certain two-dimensional materials (such as MXene) face the risk of oxidation and interlayer structural changes in air / water environments. These factors can lead to photothermal efficiency degradation and catalytic performance fluctuations, thus affecting the long-term stable operation of PMS activation.

[0007] Meanwhile, heterojunction and interface engineering strategies are widely used to improve carrier separation efficiency, broaden spectral response, and achieve more controllable interfacial electron transfer in photo-driven reactions. By constructing semiconductor / conductor or semiconductor / semiconductor heterojunctions, band structures favorable for directional charge migration can be formed at the interface, thereby suppressing electron-hole recombination and improving interfacial reaction efficiency. However, most existing heterojunction PMS activation systems still focus on improving overall activity, making it difficult to achieve the goal of "switchable / tunable ROS type"; even with the emergence of non-radical pathways (such as... 1 The phenomenon of O2 or direct electron transfer dominance often depends on complex solution conditions (such as specific pH, specific additives or specific ionic environments), and there is a lack of a simple, engineering-friendly external control method to achieve on-demand switching.

[0008] Furthermore, in existing technologies, such as patent CN119386933A, a photocatalytic PMS activation catalyst based on a Co-MOF / TiO2 heterojunction, its preparation method, and its application are disclosed. This method prepares a Co-MOF / TiO2 heterojunction hybrid material, which exhibits synergistic photocatalytic activation of bisulfate and is used to catalyze the degradation of recalcitrant bisphenol A (BPA). Under a visible light / Co-MOF / TiO2 / PMS system, the BPA removal rate in water is 99.7% within 60 minutes. However, this technology results in excessively long degradation times for BPA in water. The Co-MOF / TiO2 heterojunction hybrid material has a narrow light response range, can only utilize visible light to catalyze PMS activation, has low ROS generation, and weak oxidation capacity, making it difficult to achieve green, efficient degradation and mineralization of BPA in complex water bodies.

[0009] For example, patent CN115611355A discloses a method for removing bisphenol S (BPS) from water using a combination of sunlight and carbonate-activated persulfate. The method involves adding carbonate and persulfate to the BPS-contaminated wastewater, thoroughly mixing them, and then subjecting it to sunlight irradiation to degrade BPS. This technology, under a sunlight / carbonate / PMS system, promotes the generation of singlet oxygen and superoxide radicals, achieving a BPS removal rate of 98.1% within 120 minutes. However, this system has a BPS to PMS molar ratio of 1:50, requiring a relatively large amount of PMS, and necessitates the addition of carbonate, which is difficult to recover. Furthermore, this system primarily generates singlet oxygen and superoxide radicals, resulting in weak oxidation capacity and difficulty in removing recalcitrant organic pollutants from water.

[0010] Therefore, there is an urgent need for a PMS activation technology that can achieve switchable ROS-dominant output in a mild and controllable manner within the same system, in order to meet the targeted and efficient removal needs of different pollutants under different water quality conditions. Summary of the Invention

[0011] The purpose of this invention is to provide a catalytic material based on photo-regulated activation of persulfate, its preparation method, and its application, so as to solve the problems mentioned in the background art.

[0012] To achieve the above objectives, the present invention provides the following technical solution:

[0013] A photocatalytic material based on photo-regulated activation of persulfate, namely MoSe2 / Mo2CT x The Schottky heterojunction structure is constructed using the following method: Mo2CT x Using Mo2CT as the substrate material, interface engineering and in-situ growth strategies were employed. x MoSe2 is grown in situ on the substrate surface to construct MoSe2 / Mo2CT. x Schottky heterojunction; when the catalytic material activates persulfate, the generation pathways of multiple reactive oxygen species and the dominant reactive oxygen species can be controlled and adjusted by switching the external light irradiation mode.

[0014] Furthermore, the persulfate is a permonosulfate; the reactive oxygen species include SO4• - •OH 1 O2 and O2• - .

[0015] Another object of the present invention is to provide a method for preparing the above-mentioned photo-activated persulfate catalytic material, comprising the following steps:

[0016] Provide Mo2CT x As a substrate material;

[0017] MoSe2 was synthesized using a hydrothermal synthesis method, with Mo2CT added during the synthesis process. x In Mo2CT x MoSe2 was grown in situ on the substrate surface to obtain the catalytic material.

[0018] Furthermore, the Mo2CT x The synthesis is carried out using a hydrothermal synthesis method, specifically including:

[0019] HF was mixed with Mo2Ga2C and reacted at 20-40°C.

[0020] The reaction solution was placed at 170-190°C for reaction; the resulting product was collected by centrifugation, repeatedly washed with deionized water until the pH of the supernatant was 6.0±0.5, and then dried to obtain Mo2CT. x Material.

[0021] Furthermore, the mass-to-volume ratio of Mo2Ga2C to HF is 2g:(30-50)mL.

[0022] Furthermore, MoSe2 was synthesized using a hydrothermal synthesis method, and Mo2CT was added during the synthesis of MoSe2. x In Mo2CT x The step of in-situ growing MoSe2 on a substrate surface to obtain the catalytic material specifically includes:

[0023] Weigh out Na2MoO4•2H2O and hexadecyltrimethylammonium bromide and add them to a mixed solvent consisting of deionized water and ethanol and stir until homogeneous. Then add Se powder and NaBH4 and stir. During the stirring process, add polyethylene glycol dropwise to obtain solution A.

[0024] Preparation of Mo2CT containing hexadecyltrimethylammonium bromide x The colloidal suspension is denoted as solution B.

[0025] Solution B was added to solution A with stirring, and the mixture was stirred continuously. Then the mixture was heated to 190-210°C to carry out the reaction. The resulting product was collected by centrifugation, and after washing and drying, the catalytic material was obtained.

[0026] Further, the molar ratio of Na₂MoO₄•₂H₂O, hexadecyltrimethylammonium bromide, Se powder, and NaBH₄ is ​​2:(0.3-0.5):(3.5-4.5):(1.5-2.5); the Na₂MoO₄•₂H₂O and Mo₂CT x The molar mass ratio is 2 mmol:(3-5) mg.

[0027] Furthermore, the Mo2CT x In the colloidal suspension, the mass fraction of hexadecyltrimethylammonium bromide is 1-3 wt%, and Mo2CT x The concentration is 0.3-0.5 mg / mL.

[0028] Another objective of this invention is to provide an application of the above-mentioned photo-modulated persulfate activation catalytic material in the activation of persulfate. The method for activating persulfate includes: controlling the composition of reactive oxygen species and the dominant reaction pathway in the catalytic material and persulfate system by switching the light mode; wherein, the visible light mode is biased towards... 1 O2-dominated selective oxidation, with the full-spectrum mode forming SO4• - The main pathway is a synergistic strong oxidation pathway involving multiple reactive oxygen species.

[0029] Another object of the present invention is to provide an application of the above-mentioned photo-activated persulfate-based catalytic material in the degradation and / or mineralization of organic pollutants, wherein the catalytic material is used directly to treat organic pollutants or is loaded onto a three-dimensional conductive support before treating organic pollutants.

[0030] The catalytic material based on photo-regulated activation of persulfate provided by this invention is MoSe2 / Mo2CT. x The Schottky heterojunction structure is constructed as follows: using Mo2CT x Using Mo2CT as the substrate material, interface engineering and in-situ growth strategies were employed. x MoSe2 is grown in situ on the substrate surface to construct MoSe2 / Mo2CT. x Schottky heterojunction; this structure significantly improves the specific surface area and number of active sites of the material, effectively broadens the light absorption range, enhances photothermal conversion capability, and realizes rapid and directional migration of photogenerated carriers; at the same time, when applied to the photocatalytic-photothermal synergistic activation PMS system, the system has dual-channel characteristics of "visible light response" and "photothermal response", so that the ROS can be directionally regulated through external light source mode. Attached Figure Description

[0031] Figure 1 For MoSe2, Mo2CT x and MoSe2 / Mo2CT x XRD pattern.

[0032] Figure 2 MoSe2 / Mo2CT x SEM image.

[0033] Figure 3 MoSe2 / Mo2CT x (a) TEM image and (b) lattice size diagram.

[0034] Figure 4 MoSe2 / Mo2CT x Infrared thermal images showing dispersion under different durations of solar laser irradiation.

[0035] Figure 5 MoSe2 / Mo2CT is regulated by switching the light source (visible light / full spectrum). x - Comparison chart of BPA degradation performance of PMS system.

[0036] Figure 6 MoSe2 / Mo2CT under light source switching (visible light / full spectrum) x Comparison of ROS quenching in the PMS system for BPA degradation and the effects of ROS quenching in both systems. 1 The contribution of O2 to BPA degradation; (a) and (c) in the figure represent visible light; (b) and (d) represent the full spectrum (photothermal).

[0037] Figure 7 PMS in MoSe2 / Mo2CT under light source switching (visible light / full spectrum) xA schematic diagram of the activation reaction pathway under the action.

[0038] Figure 8 For immobilized MoSe2 / Mo2CT x A physical image of the / GF continuous flow reactor (a) and a diagram of its BPA removal performance during long-term continuous operation (b). Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] To address the core issues of existing PMS activation technologies, such as difficulty in controlling ROS types and adaptability to complex wastewater treatment requirements, this invention provides a MoSe2 / Mo2CT method. x Schottky heterojunction catalytic materials and their PMS activation method enable controllable adjustment of the ROS generation pathway through material interface engineering and light source mode switching.

[0041] Specifically, molybdenum carbide MXene (Mo2CT) x Using a two-dimensional substrate with high conductivity and strong photothermal conversion, molybdenum selenide (MoSe2) is grown in situ on its surface to construct a tightly coupled heterojunction structure. This heterojunction interface forms an effective charge migration channel and interfacial driving force, which can promote the separation of photogenerated carriers and accelerate the directional transport of electrons at the interface. Simultaneously, combined with Mo2CT... x The abundance of surface groups and MoSe2 active sites enhances PMS adsorption and activation efficiency, providing a structural basis for the directional generation of ROS.

[0042] This invention further proposes applying the above-mentioned catalytic material to construct a switchable photocatalytic-photothermal coupled PMS activation system. Using "light source switching" as an external control mechanism: under visible light conditions, the photogenerated carrier separation and interface electron transfer processes in the heterojunction preferentially drive non-radical or weakly radical pathways, making the system more inclined to generate singlet oxygen (…). 1 Selective ROS, represented by O2, are suitable for wastewater scenarios with strong ion interference or requiring selective oxidation; under photothermal conditions (such as full-spectrum / near-infrared enrichment), Mo2CT... x The photothermal conversion causes localized heating, further lowering the PMS activation barrier and enhancing interfacial electron transfer kinetics, making the system more inclined towards a radical-dominated pathway and directionally enhancing sulfate radical (SO4•) free ... -The generation rate and yield of ROS can be adjusted to achieve stronger broad-spectrum oxidation and mineralization capabilities. By adjusting the light irradiation band and mode, the type of ROS and the dominant reaction pathway can be switched and controlled within the same catalyst and reaction system, thereby enabling targeted wastewater treatment. This scheme achieves effective regulation of the PMS activation process and the ROS generation pathway, providing a novel technical strategy for the efficient and flexible treatment of complex wastewater.

[0043] In terms of application, the aforementioned MoSe2 / Mo2CT x Schottky heterojunction catalytic materials can be supported on three-dimensional conductive carriers such as carbon felt to construct immobilized catalytic layers for use in continuous flow reactors. Under PMS-containing conditions, the wastewater to be treated flows through the catalytic layer and is irradiated with visible or full-spectrum light. The appropriate light source mode is selected based on the characteristics of the target pollutant and the water quality background, and the output is... 1 O2 or SO4• - The system primarily uses oxidation to achieve efficient degradation of recalcitrant pollutants such as bisphenol A, and enables deeper mineralization when needed, while also improving system stability and engineering adaptability and reducing energy consumption.

[0044] Specifically, in one embodiment of the present invention, a catalytic material based on photo-regulated activation of persulfate, namely MoSe2 / Mo2CT, is provided. x The Schottky heterojunction structure is constructed using the following method: Mo2CT x Using Mo2CT as the substrate material, interface engineering and in-situ growth strategies were employed. x MoSe2 is grown in situ on the substrate surface to construct MoSe2 / Mo2CT. x Schottky heterojunction; when the catalytic material activates persulfate, the generation pathways of multiple reactive oxygen species and the dominant reactive oxygen species can be controlled and adjusted by switching the external light irradiation mode.

[0045] Preferably, the persulfate is permonosulfate; the reactive oxygen species include SO4• - •OH 1 O2 and O2• - .

[0046] In another embodiment of the present invention, a method for preparing the above-mentioned photo-activated persulfate catalytic material is also provided, comprising the following steps:

[0047] Provide Mo2CT x As a substrate material;

[0048] MoSe2 was synthesized using a hydrothermal synthesis method, with Mo2CT added during the synthesis process. x In Mo2CT xMoSe2 was grown in situ on the substrate surface to obtain the catalytic material.

[0049] Preferably, Mo2CT x The synthesis is carried out using a hydrothermal synthesis method, specifically including:

[0050] HF and Mo2Ga2C were mixed in a polytetrafluoroethylene beaker and reacted at 20-40°C for 20-40 min.

[0051] The reaction solution was placed in a high-pressure reactor lined with polytetrafluoroethylene and reacted at 170-190°C for 12-36 h. The resulting product was collected by centrifugation, repeatedly washed with deionized water until the pH of the supernatant reached 6.0±0.5, and then dried to obtain Mo2CT. x Material.

[0052] Preferably, the mass-to-volume ratio of Mo2Ga2C to HF is 2g:(30-50)mL; the centrifugation conditions are 4000-6000r / min and 5-15min.

[0053] Preferably, MoSe2 is synthesized using a hydrothermal synthesis method, and Mo2CT is added during the synthesis of MoSe2. x In Mo2CT x The step of in-situ growing MoSe2 on a substrate surface to obtain the catalytic material specifically includes:

[0054] Weigh out Na2MoO4•2H2O and hexadecyltrimethylammonium bromide (CTAB) and add them to a mixed solvent consisting of deionized water and ethanol and stir until homogeneous. Then add Se powder and NaBH4 and stir. During the stirring process, add polyethylene glycol dropwise to obtain solution A.

[0055] Preparation of Mo2CT containing hexadecyltrimethylammonium bromide x The colloidal suspension is denoted as solution B.

[0056] Solution B was added to solution A with stirring, and the mixture was stirred continuously. Then the mixture was heated to 190-210°C to carry out the reaction. The resulting product was collected by centrifugation, and after washing and drying, the catalytic material was obtained.

[0057] Preferably, the molar ratio of Na₂MoO₄•₂H₂O, hexadecyltrimethylammonium bromide, Se powder, and NaBH₄ is ​​2:(0.3-0.5):(3.5-4.5):(1.5-2.5); the ratio of Na₂MoO₄•₂H₂O to Mo₂CT is... x The molar mass ratio was 2 mmol:(3-5) mg; polyethylene glycol 400 (PEG400) was selected; Mo2CT xIn the colloidal suspension, the mass fraction of hexadecyltrimethylammonium bromide is 1-3 wt%, and Mo2CT x The concentration was 0.3-0.5 mg / mL; polyethylene glycol and Mo2CT x The volume ratio of the colloidal suspension is (0.1-0.3):10.

[0058] In this embodiment of the invention, Mo2CT is used through interface engineering and in-situ growth strategies. x As a two-dimensional substrate with high electrical conductivity and strong photothermal conversion, MoSe2 was grown in situ on its surface to construct MoSe2 / Mo2CT. x A catalytic material with a Schottky heterojunction structure. This structure utilizes the built-in electric field at the interface to promote the directional migration of photogenerated carriers and suppress recombination, while broadening the material's photoresponse and enhancing photothermal conversion capabilities, providing a dual-drive platform of "photocatalytic channel + photothermal channel" for PMS activation. Furthermore, it achieves directional regulation of ROS through light source switching: in visible light mode, the heterojunction preferentially enhances interfacial electron transfer and energy / electron transport processes, making the system more prone to ROS formation. 1 O2 and other active species with selective and strong resistance to matrix interference; under photothermal mode (full-spectrum or near-infrared enrichment), Mo2CT x The photothermal effect induces localized heating and lowers the activation barrier of PMS, promoting a shift towards a radical-dominated pathway in the system and significantly enhancing SO4• - The generation rate and yield are increased, thereby achieving stronger broad-spectrum oxidation and deep mineralization capabilities.

[0059] It should be noted that, in the embodiments of the present invention, some terms are explained as follows:

[0060] Bisphenol A (BPA), also known as 2,2-bis(p-hydroxyphenyl)propane, is an organic compound containing functional groups with the molecular formula C6H2O. 15 H 16 O2, with a molecular weight of 228.29. It is typically a white needle-like crystal or flaky powder with a faint phenolic odor. Its melting point is 158–159°C, boiling point is 220°C, flash point is 227°C, and density is 1.20 g / cm³. 3 It is insoluble in water, slightly soluble in carbon tetrachloride, and soluble in ethanol, ether, acetone, benzene, and dilute alkaline solutions. It is chemically stable and primarily reacts rapidly with hydroxyl radicals during its degradation process in the atmosphere.

[0061] Advanced persulfate oxidation technologies (SR-AOPs) utilize persulfates (such as PMS or PDS) as oxidants to oxidize and degrade pollutants in water by generating reactive oxygen species. This technology performs exceptionally well in treating trace amounts of persistent organic pollutants, particularly in wastewater treatment and in-situ groundwater treatment.

[0062] Peroxymonosulfuric acid, with the chemical formula H₂SO₅, also known as carboxylic acid or peroxysulfuric acid, is an inorganic compound that is a white crystalline solid at room temperature with a melting point of approximately 45°C. Its structure can be considered a sulfonated product of hydrogen peroxide. It possesses strong oxidizing and hygroscopic properties, and slowly hydrolyzes in water to produce sulfuric acid and hydrogen peroxide. Potassium persulfate is widely used as an oxidizing agent (currently the strongest known oxidizing agent, with an electrode potential of E = +2.51V).

[0063] Reactive oxygen species (ROS) are highly reactive oxygen-containing substances formed during electron transfer of oxygen molecules, including superoxide anion radicals (O2•). - Hydrogen peroxide (H2O2), hydroxyl radicals (•OH), singlet oxygen ( 1 These species, including those with oxidation-reduction potentials higher than ground-state oxygen (such as O2), exhibit the strongest oxidizing power (standard reduction potential reaching 2.8V). Their chemical properties are determined by their formation pathways and diffusion behavior. Within organisms, they participate in physiological processes such as redox signaling and energy metabolism; concentration imbalances can trigger oxidative stress. They can be generated in the environment through photocatalysis, electrocatalysis, and other pathways, and are widely used in pollutant degradation and catalytic synthesis.

[0064] MXene is a novel type of two-dimensional material composed of metal carbides or nitrides. Generally, MXene materials can be represented by the chemical formula M... n+1 X n T m The designation is as follows: "M" represents a metallic element, primarily transition metals (such as chromium, molybdenum, manganese, iron, cobalt, copper, aluminum, silver, nickel, palladium, platinum, ruthenium, etc.); "X" represents carbon and nitrogen; and "T" represents functional groups on the material's surface, such as hydroxyl groups (-OH) and halogen groups (-F, -Cl). MXene materials are among the most commonly used flexible electrode materials due to their excellent flexibility, good electronic conductivity, and superior mechanical properties. They also have broad application prospects in energy, sensing, catalysis, and biomedicine. Among them, novel conductive two-dimensional materials, represented by two-dimensional carbide / nitride MXene, possess high electrical conductivity and abundant surface functional groups (T...). xThe advantages of good hydrophilicity and the ability to construct interface structures show potential in electron transport and PMS adsorption activation. Transition metal selenides (such as MoSe2), as layered semiconductor materials, have visible light absorption capabilities and tunable electronic structures, and can provide multiple types of surface active sites. By forming tightly coupled structures of such materials through interface engineering, it is expected that both "photogenerated charge regulation capability" and "photothermal enhancement kinetic capability" can be simultaneously achieved on the same catalytic interface, thus providing a material basis for the reconstruction of PMS activation pathways and the targeted regulation of ROS types.

[0065] A Schottky junction is an interface with rectifying characteristics formed by the contact between a metal and a semiconductor. Its nonlinear impedance characteristics are similar to those of a PN junction. Its core mechanism stems from the difference in work function between the metal and the semiconductor: when a metal contacts an N-type semiconductor, electrons flow from the semiconductor into the metal, forming a space charge region and generating a built-in electric field and potential barrier. The applied voltage can adjust the barrier height; a forward bias lowers the barrier and promotes conduction, while a reverse bias strengthens the barrier and suppresses current.

[0066] Interfacial engineering refers to the precise control of the interfacial chemical environment, electronic structure, and geometry by designing and manipulating the interfacial regions between different phases, thereby optimizing material performance. This technology has important applications in many fields, especially in battery technology, catalyst design, and photovoltaic devices.

[0067] Example 1: This example provides a MoSe2 / Mo2CT based on photo-regulated activation of persulfate. x The preparation method of heterojunction catalytic materials includes the following steps:

[0068] (1) Preparation of Mo2CT x The materials and specific methods are as follows: 40 mL of HF was poured into a polytetrafluoroethylene (PTFE) beaker, and 2 g of Mo₂Ga₂C was slowly added. The mixture was reacted at 30°C for 30 min. The reaction solution was then placed in a PTFE-lined high-pressure reactor and reacted at 180°C for 24 h. After the reaction, the resulting mixture was centrifuged at 5000 r / min for 10 min, and the supernatant was discarded. Subsequently, the mixture was repeatedly sonicated, washed, and precipitated with deionized water until the pH of the supernatant was approximately 6.0. Finally, the precipitate was dried in a 60°C vacuum drying oven for 12 h, and then ground into powder to obtain Mo₂CT. x Material.

[0069] (2) Preparation of MoSe2 / Mo2CT xThe heterojunction catalytic material was prepared using the following method: First, 2 mmol of Na₂MoO₄•₂H₂O and 0.4 mol of hexadecyltrimethylammonium bromide (CTAB) were weighed and added to a mixed solvent consisting of 30 mL of deionized water and 30 mL of ethanol, and stirred thoroughly until homogeneous. Then, 4 mmol of Se ultrafine powder and 2 mmol of NaBH₄ were added, and the mixture was magnetically stirred for 30 min. Under vigorous stirring, 0.2 mL of polyethylene glycol 400 (PEG400) was slowly added dropwise, and the resulting mixture was denoted as solution A. Separately, 10 mL of Mo₂CT containing 2 wt% CTAB was prepared. x colloidal suspension (Mo2CT) x A solution with a concentration of 0.4 mg / mL was denoted as solution B. Solution B was slowly added to solution A under vigorous stirring. After magnetic stirring for 30 min, the mixture was transferred to a polytetrafluoroethylene-lined high-pressure reactor and heated to 200 °C for 18 h. After the reaction was completed and cooled to room temperature, the product was collected by centrifugation and washed three times with deionized water and ethanol, respectively. Finally, it was dried under vacuum to obtain MoSe2 / Mo2CT. x Heterojunction catalytic materials.

[0070] Example 2: This example provides a MoSe2 / Mo2CT based on photo-regulated activation of persulfate. x The preparation method of heterojunction catalytic materials includes the following steps:

[0071] (1) Preparation of Mo2CT x The materials and specific methods are as follows: 30 mL of HF was poured into a polytetrafluoroethylene (PTFE) beaker, and 2 g of Mo₂Ga₂C was slowly added. The mixture was reacted at 20°C for 20 min. The reaction solution was then placed in a PTFE-lined high-pressure reactor and reacted at 170°C for 36 h. After the reaction, the resulting mixture was centrifuged at 4000 r / min for 5 min, and the supernatant was discarded. Subsequently, the mixture was repeatedly sonicated, washed, and precipitated with deionized water until the pH of the supernatant was approximately 6.0. Finally, the precipitate was dried in a vacuum drying oven at 60°C for 12 h, and then ground into powder to obtain Mo₂CT. x Material.

[0072] (2) Preparation of MoSe2 / Mo2CT xThe heterojunction catalytic material was prepared using the following method: First, 2 mmol of Na₂MoO₄•₂H₂O and 0.3 mol of hexadecyltrimethylammonium bromide (CTAB) were weighed and added to a mixed solvent consisting of 30 mL of deionized water and 30 mL of ethanol, and stirred thoroughly until homogeneous. Then, 3.5 mmol of Se ultrafine powder and 1.5 mmol of NaBH₄ were added, and the mixture was magnetically stirred for 30 min. Under vigorous stirring, 0.1 mL of polyethylene glycol 400 (PEG400) was slowly added dropwise, and the resulting mixture was denoted as solution A. Separately, 10 mL of Mo₂CT containing 1 wt% CTAB was prepared. x colloidal suspension (Mo2CT) x A solution with a concentration of 0.3 mg / mL was denoted as solution B. Solution B was slowly added to solution A under vigorous stirring. After magnetic stirring for 30 min, the mixture was transferred to a polytetrafluoroethylene-lined high-pressure reactor and heated to 190 °C for 18 h. After the reaction was completed and cooled to room temperature, the product was collected by centrifugation and washed three times with deionized water and ethanol, respectively. Finally, it was dried under vacuum to obtain MoSe2 / Mo2CT. x Heterojunction catalytic materials.

[0073] Example 3: This example provides a MoSe2 / Mo2CT based on photo-regulated activation of persulfate. x The preparation method of heterojunction catalytic materials includes the following steps:

[0074] (1) Preparation of Mo2CT x The materials and specific methods are as follows: 50 mL of HF was poured into a polytetrafluoroethylene (PTFE) beaker, and 2 g of Mo₂Ga₂C was slowly added. The mixture was reacted at 40°C for 40 min. The reaction solution was then placed in a PTFE-lined high-pressure reactor and reacted at 190°C for 12 h. After the reaction, the resulting mixture was centrifuged at 6000 r / min for 15 min, and the supernatant was discarded. Subsequently, the mixture was repeatedly sonicated, washed, and precipitated with deionized water until the pH of the supernatant was approximately 6.0. Finally, the precipitate was dried in a 60°C vacuum drying oven for 12 h, and then ground into powder to obtain Mo₂CT. x Material.

[0075] (2) Preparation of MoSe2 / Mo2CT xThe heterojunction catalytic material was prepared using the following method: First, 2 mmol of Na₂MoO₄•₂H₂O and 0.5 mol of hexadecyltrimethylammonium bromide (CTAB) were weighed and added to a mixed solvent consisting of 30 mL of deionized water and 30 mL of ethanol, and stirred thoroughly until homogeneous. Then, 4.5 mmol of Se ultrafine powder and 2.5 mmol of NaBH₄ were added, and the mixture was magnetically stirred for 30 min. Under vigorous stirring, 0.3 mL of polyethylene glycol 400 (PEG400) was slowly added dropwise, and the resulting mixture was denoted as solution A. Separately, 10 mL of Mo₂CT containing 3 wt% CTAB was prepared. x colloidal suspension (Mo2CT) x A solution with a concentration of 0.5 mg / mL was denoted as solution B. Solution B was slowly added to solution A under vigorous stirring. After magnetic stirring for 30 min, the mixture was transferred to a polytetrafluoroethylene-lined high-pressure reactor and heated to 210 °C for 18 h. After the reaction was completed and cooled to room temperature, the product was collected by centrifugation and washed three times with deionized water and ethanol, respectively. Finally, it was dried under vacuum to obtain MoSe2 / Mo2CT. x Heterojunction catalytic materials.

[0076] Structural Characterization and Performance Testing: I. Determination of Pollutants: BPA concentration was determined using a high-performance liquid chromatography-mass spectrometry (HPLC-MS / MS) system (U3000 / TSQ quantum). The specific instrument conditions were as follows: 70% methanol and 30% ultrapure water as the mobile phase, with an injection volume of 20 μL. Mass spectrometry was performed using a HESI ion source in cation mode with full scan (m / z = 50-500 amu). The ion source temperature was set to 300℃, the ion source voltage to 4500V, the ion transfer tube temperature to 340℃, the sheath gas to 35 alb, and the auxiliary gas to 10 alb. BPA solutions of 1 mg / L, 2.5 mg / L, 5 mg / L, 7.5 mg / L, and 10 mg / L were prepared. The BPA concentration was tested using HPLC-MS / MS, a standard curve was established, and the relationship between concentration and peak area was plotted.

[0077] II. Characterization of MoSe2 / Mo2CT prepared in Example 1 by X-ray diffraction (XRD) x Heterojunction catalytic materials: The crystal structure of the catalytic materials was analyzed using X-ray diffraction (XRD). The specific test conditions were set as follows: Cu target Kα rays were used as the radiation source, with a wavelength of 1.54 Å; the scan rate was set to 0.5° per minute; the scan step size was 0.02°; and the 2θ scan range covered 5° to 80°.

[0078] Test results are as follows Figure 1 As shown, the sample displays MoSe2 (standard card PDF#29-0914) and Mo2CT. xThe typical diffraction peaks of the MoSe2 crystal are shown at 13.7°, 31.4°, 37.8°, 47.5°, 55.9°, and 69.3°, corresponding to the (002), (100), (103), (105), (110), and (203) crystal planes, respectively. The peaks at 8.94°, 28.86°, 42.10°, and 65.04° are typical diffraction peaks of the MoSe2 crystal. x The diffraction peaks prove that MoSe2 / Mo2CT x Successful synthesis.

[0079] III. Characterization of the MoSe2 / Mo2CT prepared in Example 1 by scanning electron microscopy (SEM) x Heterojunction catalytic materials: The morphology of the catalytic materials was tested using scanning electron microscopy (SEM). The specific parameters for the test were: accelerating voltage set to 20,000 volts, resolution ranging from 10 to 200 nm, and gold sputtering treatment on the sample surface before testing to enhance the observation effect.

[0080] Surface morphology of heterojunction catalytic materials, such as Figure 2 As shown, the obtained catalytic material consists of a large number of hollow hexagonal MoSe2 and layered Mo2CT. x The nanosheets are assembled together, forming a good interfacial coupling, indicating that MoSe2 / Mo2CT x Successful synthesis of heterojunction catalytic materials.

[0081] IV. Characterization of MoSe2 / Mo2CT prepared in Example 1 by transmission electron microscopy (TEM) x Heterojunction catalytic materials: Sample preparation employed an ultrafine dispersion process. 1.00±0.05 mg of the sample powder was accurately weighed using a micro-analytical balance (accuracy 0.01 mg) and dispersed in 5 mL of anhydrous ethanol using an ultrasonic cavitation dispersion system (40 kHz, 300 W) to construct a homogeneous colloidal suspension (Zeta potential >|30| mV). Subsequently, 20 μL of the suspension was quantitatively transferred using a precision pipetting system and loaded onto a 300-mesh ultrathin carbon film copper mesh substrate using gradient surface tension control technology. The sample was then dried using a vacuum drying system (10... -3 After solvent desorption at 25°C (Pa), the sample was transferred to a high-resolution transmission electron microscope (Hitachi HT-7700, accelerating voltage 100kV) for morphological characterization. Simultaneously, an Oxford energy dispersive spectrometer (X-Max N80, energy resolution 127eV) was used for elemental surface distribution analysis to ensure that the spatial resolution was better than 0.2nm and the elemental detection limit was 0.1at.

[0082] The crystal structure of heterojunction catalytic materials is as follows Figure 3 As shown, MoSe2 / Mo2CT in heterostructures xThe morphology remained unchanged, retaining a hexagonal shape with a diameter of approximately 200 nm. MoSe2 was tightly anchored to Mo2CT. x On the nanosheets, to ensure tight contact, HRTEM results showed lattice sizes of 0.64 nm and 0.26 nm, corresponding to Mo2CT. x The (100) crystal plane of MoSe2 and the (002) crystal plane of MoSe2 indicate the successful synthesis of heterojunction catalytic materials.

[0083] V. MoSe2 / Mo2CT prepared in Example 1 x Evaluation of the photothermal performance of heterojunction catalytic materials: To verify the photothermal characteristics of the materials, the photothermal conversion performance of the catalytic materials was studied. The surface temperature was measured using an infrared thermal imager under ultraviolet-visible-near-infrared light (200-2500nm) irradiation.

[0084] The results are as follows Figure 4 As shown, MoSe2 / Mo2CT x The heterojunction catalytic material was heated from 20℃ to 102.5℃ within 5 minutes, demonstrating its excellent photothermal conversion performance.

[0085] VI. Light source switching (visible light / full spectrum) to regulate MoSe2 / Mo2CT x -PMS system BPA degradation performance test

[0086] Light source switching (visible light / full spectrum) modulates MoSe2 / Mo2CT x The experiment on the degradation of BPA by the -PMS system was carried out in a photothermal catalytic reactor. First, the MoSe2 / Mo2CT prepared in Example 1 was... x The heterojunction catalyst was uniformly dispersed in a pre-prepared 10 mg / L BPA solution using ultrasound. Subsequently, PMS was added to achieve a BPA concentration ratio of 20:1. A magnetic rotor was then added, and the reaction system was subjected to catalytic oxidation under illumination (visible or full-spectrum light) at 500 rpm for 30 minutes. At regular intervals, 1 mL samples were collected, filtered through a 0.22 μm filter, and transferred to a liquid chromatography vial for subsequent BPA concentration determination. All experiments included three parallel control groups. The final result was the average of the three data sets, and the standard deviation was calculated. The uncertainty of the data was presented in the form of error bars.

[0087] MoSe2 / Mo2CT Adjusted by Different Light Sources x The experimental results of BPA degradation in the PMS system are as follows: Figure 5 As shown, compared with PMS alone, dark reaction, and light-induced catalyst-free control, MoSe2 / Mo2CT xUnder full-spectrum (photothermal) conditions, the activation efficiency of PMS can be significantly improved, enabling BPA to be almost completely removed within 20-30 minutes; while under visible light conditions, only moderate degradation is observed, indicating that the activation capacity and reaction pathway of the system can be significantly regulated by switching the light source.

[0088] VII. Characterization of Active Species in the Catalytic System under Light Source Switching Conditions: In this embodiment of the invention, the main active species generated in the catalytic system were identified using a reactive oxygen species (ROS) quenching experiment. The quenching experiment was also carried out in a photothermal catalytic reactor, with the reaction conditions being the same as those in the degradation experiment, except that the quencher, catalyst, BPA, and PMS were added to the reaction system simultaneously. Isopropanol (IPA), methanol (MeOH), tetramethylpiperidine oxide (TEMPOL), L-histidine (L-His), and potassium bromate (KBrO3) were selected as scavenging agents during the reaction, with IPA used to scavenge •OH and MeOH used to scavenge SO4• - TEMPOL is used to suppress O2• - Related bioactive species, L-His is used for capture 1 O2 and KBrO3 are used to capture photogenerated electrons (e.g., electrons). - ( ), to determine the various active species that may participate in the reaction in the system and their relative contributions.

[0089] Quenching experiment results are as follows Figure 6 As shown in figures a and b, under visible light conditions, the addition of L-His or TEMPOL resulted in the most significant inhibition of BPA degradation, while the addition of MeOH and IPA showed relatively weaker inhibition. This indicates that the system in this mode tends to degrade more significantly. 1 O2 selectively active species dominate; in contrast, under full-spectrum conditions, MeOH and IPA significantly enhance the inhibition of the reaction rate, indicating that under full-spectrum (accompanied by photothermal effect) free radical channels are effectively activated, SO4• - The participation of strong oxide species such as OH is significantly increased, resulting in faster degradation kinetics in the system. Figure 6 As shown in c and d, switch the lighting mode. 1 The contribution of O2 to BPA degradation changed from 68.5% in the visible light spectrum to 20.8% across the entire spectrum, effectively modulating the MoSe2 / Mo2CT ratio. x - The ROS composition and dominant reaction pathway of the PMS system. A schematic diagram of the activation reaction pathway of PMS under light source switching conditions is shown below. Figure 7 As shown: the visible light mode is more biased towards 1 O2-dominated selective oxidation, while the full-spectrum mode forms SO4• - The multi-ROS synergistic strong oxidation pathway, which is mainly based on pollutants, provides a mechanistic basis for achieving rapid removal and deep mineralization of pollutants.

[0090] VIII. Immobilized MoSe2 / Mo2CT x Application of / GF continuous flow reactor: MoSe2 / Mo2CT was prepared using graphite felt (GF) as a carrier via in-situ growth method. x Carbon felt (i.e., MoSe2 / Mo2CT) x / GF). For example Figure 8 As shown in figure a, the experimental system consists of BPA wastewater, a peristaltic pump, effluent, and immobilized MoSe2 / Mo2CT. x The system consists of a continuous flow reactor and a xenon lamp, simulating the treatment of actual wastewater under sunlight conditions. Figure 8 b represents the results of continuous flow experiments, demonstrating that, compared to GF alone, the loading of MoSe2 / Mo2CT... x The subsequent immobilized reactor can maintain the BPA concentration in the effluent at a near-zero level within 70 hours, achieving near-complete removal and stable operation. This demonstrates that the system provided in this embodiment of the invention has continuous catalytic oxidation / mineralization capabilities and has advantages in engineering-based continuous treatment.

[0091] In summary, the embodiments of the present invention in Mo2CT x MoSe2 was introduced into the surface through in-situ growth to form a tightly coupled MoSe2 / Mo2CT interface. x The present invention discloses a Schottky heterojunction catalytic material, which possesses Schottky contact and built-in electric field characteristics, highly efficient interfacial electron transport channels, and consequently, broad-spectrum absorption and significant photothermal conversion capabilities. Furthermore, the preparation method of the heterojunction catalytic material provided in this embodiment employs a hydrothermal / solventothermal in-situ growth process. By optimizing the selection and ratio of molybdenum source, selenium source, reducing agent, and surface modifier, as well as their addition order and reaction temperature and time, a stable heterojunction interface and reproducible photothermal performance can be ensured.

[0092] This invention embodiment uses MoSe2 / Mo2CT x Heterojunction catalytic materials are used to activate permonosulfate (PMS) to degrade / mineralize recalcitrant organic pollutants. The core technology lies in the controllable regulation of ROS generation pathways and dominant active species through switching external illumination modes (visible light and full-spectrum / photothermal modes). In particular, under the full-spectrum / photothermal mode, photothermal coupling is used to lower the PMS activation barrier and significantly enhance SO4· ... - Flux, formation of SO4• -The primary pathway involves a multi-ROS synergistic strong oxidation process, thereby enhancing the degradation rate and promoting deep mineralization. Furthermore, to achieve engineering applications, embodiments of this invention can also immobilize the catalytic material on a three-dimensional carrier such as carbon felt and construct a continuous flow reactor with a continuous operation process. This achieves the technical effects of easy recovery of the catalytic material, continuous operation, and long-term stable treatment of recalcitrant pollutants such as BPA in complex water bodies.

[0093] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification.

Claims

1. The application of a photo-regulated catalytic material for activating persulfate in the activation of persulfate, characterized in that, The catalyst is MoSe2 / Mo2CT. x The Schottky heterojunction structure is constructed using the following method: Mo2CT x Using Mo2CT as the substrate material, interface engineering and in-situ growth strategies were employed. x MoSe2 is grown in situ on the substrate surface to construct MoSe2 / Mo2CT. x Schottky heterojunction; the catalytic material, when activating persulfate, achieves controllable regulation of the generation pathways of multiple reactive oxygen species and the dominant reactive oxygen species by switching external light modes; the method for activating persulfate includes: controlling the composition of reactive oxygen species and the dominant reaction pathway in the catalytic material and persulfate system by switching light modes; wherein, the visible light mode is biased towards... 1 O2-dominated selective oxidation, with the full-spectrum mode forming SO4• - A synergistic strong oxidation pathway dominated by multiple reactive oxygen species; The preparation method of the catalytic material includes the following steps: Provide Mo2CT x As a substrate material; Weigh out Na2MoO4•2H2O and hexadecyltrimethylammonium bromide and add them to a mixed solvent consisting of deionized water and ethanol and stir until homogeneous. Then add Se powder and NaBH4 and stir. During the stirring process, add polyethylene glycol dropwise to obtain solution A. Preparation of Mo2CT containing hexadecyltrimethylammonium bromide x The colloidal suspension is denoted as solution B. Solution B was added to solution A with stirring, and the mixture was stirred continuously. Then the mixture was heated to 190-210°C to carry out the reaction. The resulting product was collected by centrifugation, and after washing and drying, the catalytic material was obtained.

2. The application according to claim 1, characterized in that, The persulfate is a permonosulfate; the reactive oxygen species include SO4• - •OH 1 O2 and O2• - .

3. The application according to claim 1, characterized in that, The Mo2CT x The synthesis is carried out using a hydrothermal synthesis method, specifically including: HF was mixed with Mo2Ga2C and reacted at 20-40°C. The reaction solution was placed at 170-190°C, and the resulting product was collected by centrifugation. The product was repeatedly washed with deionized water until the pH of the supernatant reached 6.0 ± 0.5, and then dried to obtain Mo2CT. x Material.

4. The application according to claim 3, characterized in that, The mass-to-volume ratio of Mo2Ga2C to HF is 2g:(30-50)mL.

5. The application according to claim 1, characterized in that, The molar ratio of Na₂MoO₄•₂H₂O, hexadecyltrimethylammonium bromide, Se powder, and NaBH₄ is ​​2:(0.3-0.5):(3.5-4.5):(1.5-2.5); the Na₂MoO₄•₂H₂O and Mo₂CT x The molar mass ratio is 2 mmol:(3-5) mg.

6. The application according to claim 5, characterized in that, The Mo2CT x In the colloidal suspension, the mass fraction of hexadecyltrimethylammonium bromide is 1-3 wt%, and Mo2CT x The concentration is 0.3-0.5 mg / mL.

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