Preparation method and application of zinc oxide-coated copper plasma composite photocatalytic material for phenol degradation

Abstract

A preparation method and application of a zinc oxide-coated copper plasma composite photocatalytic material for phenol degradation, which relates to a preparation method and application of a photocatalytic material. The present invention aims to solve the problem that the existing semiconductor catalyst has a competitive relationship between excitons and free charge carriers, resulting in a single deficiency of ROS generated by the semiconductor in the photocatalytic system. The present invention uses ZnO, a direct bandgap semiconductor with a good exciton dissociation effect, as a substrate, and introduces bulk oxygen vacancies and elemental copper with a plasmon resonance effect in situ to precisely control the balance between excitons and photogenerated carriers, thereby achieving the generation of enriched oxidative active species in the photocatalytic system. Method: 1. Material mixing; 2. Hydrothermal reaction. Application: It is used as a photocatalyst for the photocatalytic degradation of phenol. The present invention discloses the preparation and application of a zinc oxide-coated copper plasma composite photocatalytic material for phenol degradation.

Description

Technical Field

[0001] The invention relates to a preparation method of a photocatalytic material and application thereof. Background Art

[0002] As a common organic compound, phenol is widely used in the chemical, pharmaceutical, dye and other industries. Due to its high toxicity and difficulty in degradation, it is often discharged into the water environment as the main pollutant in industrial wastewater, posing a huge potential threat to water quality, ecological safety and human health. Based on this, it is very necessary to effectively treat phenol pollutants in the water environment to protect the environment and public health. At present, the common phenol-containing wastewater treatment processes are mainly divided into traditional treatment processes, such as biological methods, chemical methods and adsorption methods, etc., and advanced oxidation processes such as electrochemical oxidation, sonochemical oxidation and photocatalytic degradation. Among them, photocatalytic technology can convert low-density solar energy into high-density chemical energy through photocatalysts, thereby achieving complete mineralization of pollutants, minimizing the consumption of chemicals and the generation of secondary pollution, and has obvious advantages in environmental friendliness and ease of operation.

[0003] Hydroxyl radicals, as the representative free radical in photodegradation systems, exhibit excellent oxidative capacity due to their high redox potential. However, their short half-life, demanding pH requirements, and sensitivity to inorganic ions limit their application in the degradation of organic pollutants. Superoxide radicals, while possessing a longer half-life, are relatively weak in reactivity and oxidative capacity, hindering their development in aquatic environments. Furthermore, singlet oxygen, as the only oxygen-containing non-radical, has attracted considerable research attention due to its high selectivity, strong anti-interference ability, and good pH tolerance. However, this strong selectivity also limits its universality in the degradation of organic pollutants, significantly hindering its expansion in applications. Therefore, the use of single reactive oxygen species in the treatment of phenolic wastewaters is significantly limited. Enriching the generation of ROS and their synergistic catalytic oxidation is a potential development trend for pollutant removal in complex aquatic environments.

[0004] In recent years, photocatalytic advanced oxidation processes based on semiconductor catalysts have attracted much attention due to their high efficiency, green nature, and environmental friendliness. Furthermore, due to the unique band structure and photoresponsiveness of semiconductors, charge carriers (photogenerated electron-hole pairs) or excitons (bound states of photogenerated electron-hole pairs) are generated within them under photoexcitation conditions. The presence of charge carriers is beneficial for reducing oxygen or activating water molecules, thereby generating superoxide anions and hydroxyl radicals, respectively. Furthermore, excitons can directly excite oxygen molecules through energy transfer to produce singlet oxygen. However, from the perspective of electron-hole separation, the existence of excitons and charge carriers within a single semiconductor is a complementary and regular relationship (excitons dissociate to generate free charge carriers, while bound states of photogenerated carriers are excitons). This results in the ROS generated by semiconductor photocatalytic systems being often single and scarce. Therefore, precisely controlling semiconductor photocatalysts that exhibit both exciton and charge carrier effects to achieve a reasonable balance between exciton and charge carrier generation, thereby promoting the generation of multiple types of reactive oxygen species, has important practical implications for addressing environmental issues. Summary of the Invention

[0005] The present invention aims to solve the problem that the competition between excitons and free charge carriers in existing semiconductor catalysts leads to a single shortage of ROS generated by semiconductors in photocatalytic systems, and further provides a preparation method and application of a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol. The present invention uses ZnO, a direct bandgap semiconductor with good exciton dissociation effect, as a substrate, and in situ introduces bulk oxygen vacancies and elemental copper with plasmon resonance effect to effectively balance the generation competition between excitons and free charge carriers, accurately regulate the balance between excitons and photogenerated carriers, greatly improve the generation path of active oxygen species, and thus achieve the enrichment of the generation of oxidative active species in the photocatalytic system. The prepared catalyst has an excellent LSPR effect and abundant bulk oxygen defects, and exhibits excellent photodegradation activity in the treatment of phenol-containing wastewater.

[0006] A method for preparing a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol is carried out according to the following steps:

[0007] 1. Material mixing:

[0008] At room temperature, copper nitrate trihydrate, glucose and nano zinc oxide are added to an organic solvent, stirred and then ultrasonicated to obtain a mixed solution;

[0009] 2. Hydrothermal reaction:

[0010] The mixed solution is hydrothermally reacted at a temperature of 160°C to 180°C for 6h to 12h, then naturally cooled to room temperature, and finally filtered, washed and dried to obtain Cu@ZnO-C, thereby completing the preparation method of zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol.

[0011] The invention discloses an application of a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol, wherein the zinc oxide-coated copper plasma composite photocatalytic material is used as a photocatalyst for photocatalytic degradation of phenol.

[0012] The beneficial effects of the present invention are:

[0013] The present invention provides a photocatalytic material for degrading phenol. Through a simple one-pot hydrothermal synthesis process, a heterojunction material rich in bulk oxygen vacancies was constructed in situ. By introducing plasma metal Cu and bulk oxygen vacancies, a catalyst with a localized surface plasmon resonance (LSPR) effect and an efficient intersystem crossing (ISC) process was synthesized. This unique design enables the catalyst to effectively balance the generation competition between excitons and carriers, thereby promoting the generation of multiple types of active oxygen species. Among them, the bulk oxygen vacancies serve as the recombination center of excitons and carriers, which contributes to the generation of singlet excitons in the photocatalytic system. Through the efficient ISC process, the singlet excitons are further converted into triplet excitons, which contributes to the direct activation of molecular oxygen in the energy transfer process, accelerates the energy transfer, and generates non-radical singlet oxygen. In addition, the LSPR effect injects a large number of high-energy carriers into the photocatalytic system. These carriers are rapidly transferred by hot electrons driven by the built-in electric field, significantly improving the generation efficiency of free charge carriers, helping more electrons and holes to participate in the generation process of ROS, and thus stimulating the generation of more highly active free radicals. Therefore, the optimized Cu@ZnO-C heterojunction exhibits excellent photocatalytic activity, achieving 100% degradation of phenol within 30 minutes. At the same time, Cu@ZnO-C also exhibits excellent photodegradation effects on other pollutants, proving that the catalyst has good universality. Therefore, the present invention provides a new strategy for exploring photocatalysts for the generation of multi-path reactive oxygen species. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 X-ray diffraction patterns of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3;

[0015] Figure 2 This is a scanning electron microscope image of the photocatalytic material prepared in Example 1;

[0016] Figure 3 This is a transmission electron micrograph of the photocatalytic material prepared in Example 1;

[0017] Figure 4The UV-visible diffuse reflectance spectra of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3 are shown;

[0018] Figure 5 Surface potential diagrams and corresponding surface photovoltage diagrams of the photocatalytic materials prepared in Example 1 and Comparative Example 1, a1 is the surface potential diagram and corresponding surface photovoltage diagram of ZnO under dark conditions, a2 is the surface potential diagram and corresponding surface photovoltage diagram of ZnO under light conditions, b1 is the surface potential diagram and corresponding surface photovoltage diagram of Cu@ZnO-C under dark conditions, b2 is the surface potential diagram and corresponding surface photovoltage diagram of Cu@ZnO-C under light conditions;

[0019] Figure 6 Infrared thermal imaging images of the photocatalytic materials prepared in Example 1 and Comparative Example 1, a is ZnO, b is Cu@ZnO-C;

[0020] Figure 7 The fluorescence and phosphorescence spectra of the photocatalyst materials prepared in Example 1 and Comparative Example 1 are shown in Figures a and b, respectively, where a is a steady-state transient fluorescence spectrum, b is a transient fluorescence spectrum, c is a steady-state phosphorescence spectrum, and d is a transient phosphorescence spectrum.

[0021] Figure 8 : The electron spin resonance spectra of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3 are shown; a is a quenching experiment diagram of the photocatalytic material prepared in Example 1; b is the change in singlet oxygen intensity before and after the addition of p-benzoquinone to the photocatalytic material prepared in Example 1; c is the change in hole signal of the photocatalytic material prepared in Example 1 under light and dark conditions; d, e, and f are electron paramagnetic spin resonance spectra of hydroxyl radicals, singlet oxygen radicals, and superoxide radicals of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3, respectively;

[0022] Figure 9 Electron paramagnetic resonance spectra of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3;

[0023] Figure 10 Graph showing the photocatalytic degradation performance of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3;

[0024] Figure 11 This is a cyclic stability test chart of the photocatalytic material prepared in Example 1. DETAILED DESCRIPTION

[0025] Specific embodiment 1: This embodiment is a preparation method of a zinc oxide copper plasma composite photocatalytic material for degrading phenol, which is carried out according to the following steps:

[0026] 1. Material mixing:

[0027] At room temperature, copper nitrate trihydrate, glucose and nano zinc oxide are added to an organic solvent, stirred and then ultrasonicated to obtain a mixed solution;

[0028] 2. Hydrothermal reaction:

[0029] The mixed solution is hydrothermally reacted at a temperature of 160°C to 180°C for 6h to 12h, then naturally cooled to room temperature, and finally filtered, washed and dried to obtain Cu@ZnO-C, thereby completing the preparation method of zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol.

[0030] The beneficial effects of this embodiment are:

[0031] The present embodiment provides a photocatalytic material for degrading phenol. Through a simple one-pot hydrothermal synthesis process, a heterojunction material rich in bulk oxygen vacancies was constructed in situ. By introducing plasma metal Cu and bulk oxygen vacancies, a catalyst with a localized surface plasmon resonance (LSPR) effect and an efficient intersystem crossing (ISC) process was synthesized. This unique design enables the catalyst to effectively balance the generation competition between excitons and carriers, thereby promoting the generation of multiple types of active oxygen species. Among them, the bulk oxygen vacancies serve as the recombination center of excitons and carriers, which contributes to the generation of singlet excitons in the photocatalytic system. Through the efficient ISC process, the singlet excitons are further converted into triplet excitons, which contributes to the direct activation of molecular oxygen in the energy transfer process, accelerates energy transfer, and generates non-radical singlet oxygen. In addition, the LSPR effect injects a large number of high-energy carriers into the photocatalytic system. These carriers are rapidly transferred by hot electrons driven by the built-in electric field, significantly improving the generation efficiency of free charge carriers, helping more electrons and holes to participate in the generation process of ROS, thereby stimulating the generation of more highly active free radicals. Therefore, the optimized Cu@ZnO-C heterojunction exhibits excellent photocatalytic activity, achieving 100% degradation of phenol within 30 minutes. At the same time, Cu@ZnO-C also exhibits excellent photodegradation effects on other pollutants, proving that the catalyst has good universality. Therefore, this embodiment provides a new strategy for exploring photocatalysts for the generation of multi-path reactive oxygen species.

[0032] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the organic solvent in step 1 is N,N-dimethylformamide solution. Other steps are the same as those in specific embodiment 1.

[0033] Specific embodiment 3: This embodiment differs from specific embodiment 1 or 2 in that the mass ratio of glucose to copper nitrate trihydrate in step 1 is 1:(2-5). Other aspects are the same as specific embodiment 1 or 2.

[0034] Specific embodiment 4: This embodiment differs from specific embodiments 1 to 3 in that the mass ratio of glucose to nano zinc oxide in step 1 is 1:(60-70). Other aspects are the same as specific embodiments 1 to 3.

[0035] Specific embodiment 5: This embodiment differs from Specific embodiments 1 to 4 in that the volume ratio of the glucose mass to the organic solvent in step 1 is 1 g: (1100-1200) mL. Other aspects are the same as Specific embodiments 1 to 4.

[0036] Specific embodiment 6: This embodiment differs from Specific embodiments 1 to 5 in that, in step 1, copper nitrate trihydrate, glucose, and nano-zinc oxide are added to an organic solvent at room temperature, then stirred at a stirring speed of 200 rpm to 500 rpm for 5 to 10 minutes, and then ultrasonically treated at a power of 100 kW to 400 kW for 15 to 45 minutes to obtain a mixed solution. Other steps are the same as Specific embodiments 1 to 5.

[0037] Specific embodiment 7: This embodiment differs from Specific embodiments 1 to 6 in that the washing and drying in step 2 are specifically performed using deionized water and anhydrous ethanol, followed by vacuum drying at a temperature of 40°C to 60°C for 8 to 12 hours. Other aspects are the same as Specific embodiments 1 to 6.

[0038] Specific embodiment eight: This embodiment provides an application of a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol, which is used as a photocatalyst for photocatalytic degradation of phenol.

[0039] Specific embodiment 9: This embodiment differs from specific embodiment 8 in that it is used as a photocatalyst for photocatalytic degradation of phenol, specifically by the following steps:

[0040] The Cu@ZnO-C was mixed with the solution to be treated, and then the solution was heated at a wavelength of 320 nm to 780 nm and a power density of 1.767 W / cm 2 ~7.07W / cm 2 The light treatment is carried out for 30 to 90 minutes under the conditions of . Other steps are the same as those in the eighth embodiment.

[0041] Specific embodiment 10: This embodiment differs from either specific embodiment 8 or 9 in that the ratio of the mass of the Cu@ZnO-C to the volume of the solution to be treated is 10 mg:(50-100) mL; and the concentration of phenol in the solution to be treated is 10 mg / L to 1000 mg / L. Other aspects are the same as specific embodiments 8 or 9.

[0042] The following examples are used to verify the beneficial effects of the present invention:

[0043] Example 1:

[0044] A method for preparing a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol is carried out according to the following steps:

[0045] 1. Material mixing:

[0046] At room temperature, 0.0968 g of copper nitrate trihydrate, 0.036 g of glucose, and 2.33 g of nano-zinc oxide were added to 40 mL of an organic solvent, and then stirred at a stirring speed of 400 rpm for 5 min, and then ultrasonicated at a power of 300 kW for 30 min to obtain a mixed solution;

[0047] The particle size of the nano zinc oxide is 80nm to 100nm; the organic solvent is N,N-dimethylformamide solution;

[0048] 2. Hydrothermal reaction:

[0049] The mixed solution was placed in a sealed polytetrafluoroethylene-lined stainless steel autoclave and hydrothermally reacted at 180°C for 6 hours. The mixed solution was then naturally cooled to room temperature and finally filtered, washed and dried to obtain a photocatalytic material, namely Cu@ZnO-C.

[0050] The washing and drying in step 2 specifically involves washing with deionized water and anhydrous ethanol three times, and then vacuum drying at a temperature of 60° C. for 12 hours.

[0051] Comparative Example 1: This comparative example differs from Example 1 in that copper nitrate trihydrate and glucose are omitted in step 1, 2.33 g of nano zinc oxide is added to 40 mL of water, and ZnO is obtained in step 2. The rest is the same as in Example 1.

[0052] Comparative Example 2: This comparative example differs from Example 1 in that glucose is omitted in step 1, 0.0968 g of copper nitrate trihydrate and 2.33 g of nano zinc oxide are added to 40 mL of organic solvent, and Cu@ZnO is obtained in step 2. The rest of the reaction is the same as in Example 1.

[0053] Comparative Example 3:

[0054] 1. Material mixing:

[0055] At room temperature, 2.33 g of nano-zinc oxide was added to 40 mL of 0.005 M glucose aqueous solution, and then stirred at a stirring speed of 400 rpm for 5 minutes, and then ultrasonicated at a power of 300 kW for 30 minutes to obtain a mixed solution;

[0056] The particle size of the nano zinc oxide is 80nm to 100nm;

[0057] 2. Hydrothermal reaction:

[0058] The mixed solution was placed in a sealed polytetrafluoroethylene-lined stainless steel autoclave and subjected to hydrothermal reaction at 180°C for 6 hours. The mixed solution was then naturally cooled to room temperature and centrifuged at 10,500 rpm for 10 minutes to separate the supernatant and precipitate. The precipitate was washed and dried to obtain a photocatalytic material, namely, ZnO@C.

[0059] The washing and drying in step 2 specifically involves washing with deionized water and anhydrous ethanol three times, and then vacuum drying at a temperature of 60° C. for 12 hours.

[0060] Figure 1 The X-ray diffraction patterns of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3 are shown. As can be seen from the figure, the Cu@ZnO-C photocatalyst has eleven characteristic diffraction peaks at 31.76°, 34.42°, 36.25°, 47.53°, 56.60°, 62.86°, 66.37°, 67.96°, 69.09°, 72.56° and 76.95°, which correspond to the (100), (002), (101), (102), (110), (103), (200), (112), (201), (004) and (202) crystal planes of ZnO, respectively. In addition, the three obvious diffraction peaks at 43.29°, 50.43° and 74.13° are attributed to the (111), (200) and (220) crystal planes of Cu, respectively.

[0061] Figure 2 This is a scanning electron microscope image of the photocatalytic material prepared in Example 1. As can be seen from the image, irregular spherical ZnO particles are dispersed around the metal Cu.

[0062] Figure 3 This is a transmission electron micrograph of the photocatalytic material prepared in Example 1. As can be seen from the figure, the Cu@ZnO-C has clear lattice fringes, and the measured spacing is 0.22nm and 0.273nm, corresponding to the (111) crystal plane of Cu and the (002) characteristic plane of ZnO, respectively.

[0063] Figure 4The UV-visible diffuse reflectance spectra of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3 are shown. As can be seen from the figure, compared with pure ZnO, the light absorption of the Cu@ZnO-C composite catalyst in the near-infrared region is significantly enhanced. This enhancement is attributed to the near-field coupling and far-field scattering caused by the localized surface plasmon resonance effect. Calculated by the Tauc formula, the band gap width (Eg) of ZnO is 3.242eV, while the band gap width (Eg) of the Cu@ZnO-C composite catalyst is reduced to 3.228eV. This result shows that the LSPR effect introduced by metallic Cu not only effectively reduces the band gap width of the photocatalyst, but also significantly expands its light response range.

[0064] Figure 5 The surface potential diagram and the corresponding surface photovoltage diagram of the photocatalytic material prepared in Example 1 and Comparative Example 1, a1 is the surface potential diagram and the corresponding surface photovoltage diagram of ZnO under dark conditions, a2 is the surface potential diagram and the corresponding surface photovoltage diagram of ZnO under light conditions, b1 is the surface potential diagram and the corresponding surface photovoltage diagram of Cu@ZnO-C under dark conditions, b2 is the surface potential diagram and the corresponding surface photovoltage diagram of Cu@ZnO-C under light conditions; It can be seen from the figure that for the Cu@ZnO-C heterojunction, under light conditions, the potential of site C rises from 1062mV to 1082mV (denoted as C2), while the potential of site D drops from 1017.49mV to 1017.31mV (denoted as D2). This change shows that the transfer process of electrons from site C to site D is closely related to the introduction of light. In contrast, the potential change of ZnO before and after illumination is not obvious. In addition, the surface potential shift difference (ΔSP) of Cu@ZnO-C is larger, further indicating that its electron transfer process is more intense. These results indicate that in the composite photocatalyst Cu@ZnO-C, hot carriers on Cu can be effectively transferred to ZnO under light conditions.

[0065] The photocatalytic materials prepared in Example 1 and Comparative Example 1 were irradiated using a xenon lamp with a power of 300 W and a current of 15 A; Figure 6 The infrared thermal imaging images of the photocatalytic materials prepared in Example 1 and Comparative Example 1, a is ZnO, and b is Cu@ZnO-C. It can be seen from the figure that after 60 seconds of xenon lamp irradiation, the center temperatures of ZnO and Cu@ZnO-C rose to 91.9°C and 123.9°C, respectively. This result shows that the heating rate of the Cu@ZnO-C composite photocatalyst is significantly higher than that of pure ZnO. This significant temperature difference indicates that under light conditions, the presence of Cu enables energy to be efficiently transferred from Cu to ZnO. In addition, the Cu@ZnO-C composite photocatalyst exhibits better photothermal conversion ability, which further proves the existence of the localized surface plasmon resonance (LSPR) effect and its significant enhancement of photothermal performance.

[0066] Figure 7 The fluorescence and phosphorescence spectra of the photocatalyst materials prepared in Example 1 and Comparative Example 1 are shown in Figures a and b, c, and d, respectively. Figure 7 In a, the fluorescence spectrum peak of the Cu@ZnO-C sample is lower than that of the ZnO sample, indicating that the concentration of singlet excitons in the Cu@ZnO-C photocatalytic system is relatively low, which may be due to the rapid conversion of singlet excitons ( Figure 7 a). Figure 7 In b, the fluorescence lifetimes of Cu@ZnO-C and ZnO are 13.38μs and 21.84μs, respectively, which indicates that the conversion rate of singlet excitons to triplet excitons in Cu@ZnO-C is faster, resulting in a significant shortening of the fluorescence lifetime. Figure 7 In c, the phosphorescence intensity of Cu@ZnO-C is higher than that of ZnO, which indicates that the production of triplet excitons in the Cu@ZnO-C system is higher, which is conducive to the generation of singlet oxygen through the energy transfer process. Figure 7 In Figure d, the phosphorescence lifetimes of Cu@ZnO-C and ZnO are 11.06 ms and 7.15 ms, respectively. Overall, the fluorescence intensity of the Cu@ZnO-C sample decreases and the fluorescence lifetime shortens, while the phosphorescence intensity increases and the phosphorescence lifetime increases. These results indicate that the conversion efficiency of singlet excitons to triplet excitons in Cu@ZnO-C is significantly improved.

[0067] Figure 8 Figure 1 is the electron spin resonance spectrum of the photocatalytic material prepared in Example 1 and Comparative Examples 1 to 3, a is the quenching experiment diagram of the photocatalytic material prepared in Example 1, b is the change in singlet oxygen intensity before and after the addition of p-benzoquinone to the photocatalytic material prepared in Example 1, c is the change in hole signal of the photocatalytic material prepared in Example 1 under light and dark conditions, d, e and f are the electron paramagnetic spin resonance spectra of hydroxyl radicals, singlet oxygen radicals and superoxide radicals of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3, respectively; It can be seen from Figure a that singlet oxygen, holes and hydroxyl radicals play an important role in the photodegradation process of phenol. Figure b shows that after the addition of p-benzoquinone (p-BQ), the intensity of singlet oxygen is significantly reduced, which proves that singlet oxygen is generated through an energy transfer mechanism, and at the same time by Figure 6 and 7 Figure a demonstrates that the generation process is closely related to the mediation of excitons. Figure c demonstrates the presence of holes in the catalyst. Figures d, e, and f demonstrate the diversity of reactive oxygen species in the photocatalytic system, indicating that the catalyst can effectively generate a variety of reactive oxygen species, thereby promoting the photocatalytic degradation process.

[0068] Figure 9The electron paramagnetic resonance spectra of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3 are shown in FIG. 1 . As can be seen from the figure, the EPR signal intensity shows that the composite photocatalytic material has a higher concentration of bulk oxygen vacancies.

[0069] 10 mg of photocatalytic material was mixed with 100 mL of the solution to be treated. The reaction was first conducted in the dark for 30 min to avoid the influence of adsorption on the test results. Then, the photocatalytic material was tested at a wavelength of 320 nm to 780 nm and a power density of 2.55 W / cm 2 The solution was treated with light for 90 minutes under the conditions of 1000 nm. The concentration of phenol in the solution to be treated was 10 mg / L. During the cyclic test, the catalyst was recovered by filtration after the reaction, and the recovered catalyst was added to a new batch of solution to be treated and treated again under the above conditions. This cycle was repeated 5 times. Figures 10 and 11 .

[0070] Figure 10 The photocatalytic degradation performance diagram of the photocatalytic materials prepared in Example 1 and Comparative Examples 1 to 3. Under light irradiation conditions, the composite material Cu@ZnO-C can achieve 100% degradation effect after 30 minutes.

[0071] Figure 11 This is a cyclic stability test chart of the photocatalytic material prepared in Example 1. The results show that the sample performed excellently in the phenol degradation process, with the degradation efficiency always stable at above 95%, demonstrating extremely excellent performance stability.

[0072] In summary, the bulk-oxygen-deficient Cu@ZnO-C heterojunction, exhibiting an outstanding LSPR effect, successfully achieves a dynamic equilibrium between excitons and free charge carriers, establishing a platform for the efficient multi-pathway generation of reactive oxygen species in photodegradation systems. Photoluminescence analysis reveals that bulk oxygen vacancies, acting as electron-hole recombination centers, effectively promote the formation of singlet excitons, facilitating the in situ activation of molecular oxygen to generate long-lived non-radical singlet oxygen via energy transfer pathways. Simultaneously, the LSPR-induced high-energy hot electrons undergo directional migration under the action of the built-in electric field, significantly improving the separation efficiency of electron-hole pairs and enhancing the concentrations of hydroxyl and superoxide radicals in the photodegradation system. Through the synergistic action of both free and non-radical species, the Cu@ZnO-C heterojunction exhibits excellent photocatalytic degradation performance, achieving complete degradation of phenol within 30 minutes. Furthermore, the heterojunction also exhibits efficient degradation of a variety of organic pollutants, demonstrating the catalyst's broad applicability. This preparation strategy provides a new approach for the development of photocatalysts for the generation of reactive species through multi-pathways.

Claims

1. A method for preparing a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol, characterized in that It is carried out in the following steps:

1. Material mixing: At room temperature, copper nitrate trihydrate, glucose, and nano-zinc oxide are added to an organic solvent, followed by stirring at a stirring speed of 200 rpm to 500 rpm for 5 to 10 minutes, and then ultrasonically applied at a power of 100 kW to 400 kW for 15 to 45 minutes to obtain a mixed solution; The organic solvent is N,N-dimethylformamide solution; the mass ratio of glucose to copper nitrate trihydrate is 1:(2-5); the mass ratio of glucose to nano zinc oxide is 1:(60-70); the volume ratio of glucose mass to organic solvent is 1g:(1100-1200)mL; 2. Hydrothermal reaction: The mixed solution was hydrothermally reacted at a temperature of 160°C to 180°C for 6 hours to 12 hours, then naturally cooled to room temperature, and finally filtered, washed, and dried to obtain Cu@ZnO-C, thereby completing the preparation method of the zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol. The washing and drying specifically comprises washing with deionized water and anhydrous ethanol, and then vacuum drying at a temperature of 40° C. to 60° C. for 8 h to 12 h.

2. The use of a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol prepared as claimed in claim 1, characterized in that It is used as a photocatalyst for the photocatalytic degradation of phenol.

3. The use of a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol according to claim 2, characterized in that It is used as a photocatalyst for the photocatalytic degradation of phenol, specifically in the following steps: The Cu@ZnO-C was mixed with the solution to be treated, and then the solution was heated at a wavelength of 320 nm to 780 nm and a power density of 1.767 W / cm 2 ~7.07 W / cm 2 Under the conditions of light treatment for 30min~90min.

4. The use of a zinc oxide-coated copper plasma composite photocatalytic material for degrading phenol according to claim 2, characterized in that The mass ratio of the Cu@ZnO-C to the volume of the solution to be treated is 10 mg:(50-100) mL; the concentration of phenol in the solution to be treated is 10 mg / L-1000 mg / L.

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