Preparation method of TiO2 / Sb2O3 / PSAC heterojunction sterilization composite material

Abstract

The application relates to a preparation method of a TiO2 / Sb2O3 / PSAC heterojunction sterilization composite material, which comprises the following steps: 1) adding a cationic surfactant, tetrabutyl titanate, antimony trichloride or antimony pentachloride into deionized water in sequence and stirring until the solution is white; 2) placing a FOSS crucible with coal-tar pitch-based spherical activated carbon into a high-pressure reaction kettle with concentrated nitric acid, heating, washing with deionized water until neutral, and naturally air-drying; 3) placing the dried coal-tar pitch-based spherical activated carbon into the white solution, stirring, finally adding sodium hydroxide, stirring, and then placing into a high-pressure reaction kettle, heating and keeping for a period of time; and naturally cooling, centrifugalizing, washing and drying. The application effectively combines the adsorption performance and the photocatalytic performance of the activated carbon through a hydrothermal one-step in-situ method, increases the mechanical performance, and can have high sterilization efficiency under the excitation of sunlight.

Description

Technical Field

[0001] This invention belongs to the field of water treatment bactericidal materials, and particularly relates to a method for preparing a TiO2 / Sb2O3 / PSAC heterojunction bactericidal composite material. Background Technology

[0002] With the tremendous progress of human society, environmental pollution problems have inevitably arisen, especially the increasingly serious pollution of water resources. Among the many water pollutants, microbial pollution is the main source, which greatly affects human health and poses a threat to modern society.

[0003] In recent years, people have paid increasing attention to water pollution and have developed corresponding strategies to address this issue. These include the preparation of organic and inorganic antibacterial agents. Inorganic antibacterial agents are widely used due to their broad-spectrum antibacterial properties and safety, primarily employing metal ions (such as silver, copper, and zinc ions) for antibacterial activity. However, the antibacterial effect of metal ions carries the risk of secondary pollution due to ion diffusion. Organic antibacterial agents offer advantages such as a wide variety of products, good timeliness, and strong bactericidal power; however, they have disadvantages such as poor heat resistance, high toxicity, and the potential for pathogenic microorganisms to develop drug resistance.

[0004] In comparison, photocatalytic antibacterial materials have attracted widespread attention in the fields of antibacterial and photocatalysis due to their good antibacterial properties, photocatalytic performance, low cost, and stability.

[0005] Titanium dioxide (TiO2) is one of the most studied photocatalysts for environmental remediation. Under ultraviolet light irradiation, its valence band generates a positive charge, causing the adsorbed water or OH groups on its surface to become positively charged. - It is rapidly converted into OH· radicals for subsequent oxidation of pollutants. However, the bactericidal efficiency and effect of using a single titanium dioxide photocatalyst for wastewater treatment are poor, making it difficult to apply in engineering. Recently, heterogeneous photocatalysis technology has been widely used in wastewater treatment and air purification. In particular, semiconductor bimetallic oxides, due to their good stability, strong redox ability, low toxicity, and good photophysical properties, are widely used as photocatalysts for the decomposition of organic and air pollutants. Sb2O3 is a novel semiconductor with a wide bandgap of over 3 eV. Combining it with TiO2 to prepare heterojunction materials is one of the effective ways to improve the photocatalytic performance of titanium dioxide, and TiO2 / Sb2O3 heterojunction materials have received little attention.

[0006] Secondly, activated carbon has advantages such as large specific surface area and strong adsorption capacity, and is widely used as an adsorbent in water treatment. Among them, coal tar pitch-based spherical activated carbon (PSAC) has high packing density and flowability due to its spherical structure, making it a leader among water treatment adsorbents. By combining it with TiO2 / Sb2O3 heterojunction materials, TiO2 / Sb2O3 / PSAC bactericidal materials with excellent adsorption and bactericidal properties can be prepared. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the purpose of this invention is to provide a simple method for preparing a TiO2 / Sb2O3 / PSAC heterojunction bactericidal composite material. This composite activated carbon ball can effectively adsorb suspended solids and pollutants in water and kill bacteria in water under ultraviolet light excitation.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A method for preparing a TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material includes the following steps:

[0010] 1) Add 0.01-0.15g of cationic surfactant, 1.5-3g of tetrabutyl titanate, and 0.2-0.9g of antimony trichloride or antimony pentachloride to 40-80mL of deionized water and stir until the pH value is ≥10 and the solution turns pure white.

[0011] 2) Weigh 0.1-0.3g of coal tar pitch-based spherical activated carbon and place it on top of the FOSS crucible. Then place the FOSS crucible in a high-pressure reactor containing concentrated nitric acid, heat to 150-180℃, maintain for 2-5 hours, cool naturally to room temperature, rinse with deionized water until neutral, and air dry naturally.

[0012] 3) Place the dried coal tar pitch-based spherical activated carbon into the pure white solution obtained in step 1), stir for 10-30 min, and finally add 0.3-0.6 g of sodium hydroxide. After stirring for 0.5-1.5 h, place it in a high-pressure reactor and maintain it at 80-120℃ for 10-14 h. After natural cooling, centrifuge the mixture and wash it 3-5 times with deionized water and anhydrous ethanol, respectively. Finally, dry the mixture to obtain the TiO2 / Sb2O3 / PSAC composite material.

[0013] The cationic surfactant is one of hexadecyltrimethylammonium bromide, dodecyldimethylbenzylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.

[0014] The concentrated nitric acid mentioned in step 2) is 1-4 ml.

[0015] In step 2), the FOSS crucible is placed inside the polytetrafluoroethylene liner of the high-pressure reactor, and a weighing bottle containing concentrated nitric acid is placed underneath it. The high-pressure reactor is then sealed.

[0016] The pH value of the solution described in step 1) is ≥10.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] This invention utilizes a one-step hydrothermal in-situ method to load TiO2 / Sb2O3 heterojunction material onto coal tar pitch-based spherical activated carbon (PSAC) with a large specific surface area. This effectively combines the adsorption and photocatalytic properties of activated carbon and significantly enhances its mechanical properties, enabling the composite material to exhibit high bactericidal efficiency under sunlight excitation, effectively killing bacteria in water. Applying this type of composite spherical activated carbon to aquaculture water treatment not only overcomes the shortcomings of materials like TiO2, such as poor wear resistance and easy detachment, but also greatly reduces energy consumption due to its absorption characteristics in the visible light range. Attached Figure Description

[0019] Figure 1 This is a flowchart of the preparation process for TiO2 / Sb2O3 / PSAC composite materials.

[0020] Figure 2 These are the XRD patterns of PSAC, TiO2 / Sb2O3, and TiO2 / Sb2O3 / PSAC.

[0021] Figure 3 These are XPS spectra of TiO2 / Sb2O3 and TiO2 / Sb2O3 / PSAC.

[0022] Figure 4 This is a TEM image of TiO2 / Sb2O3.

[0023] Figure 5 These are isothermal nitrogen adsorption-desorption curves and pore size distribution diagrams for PSAC (carbonized or activated), TiO2 / Sb2O3 / PSAC.

[0024] Figure 6 This is a picture showing the sterilization effect. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0026] Example 1

[0027] See Figure 1 Preparation of TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material:

[0028] 1) Add 0.1g of hexadecyltrimethylammonium bromide, 2.4g of tetrabutyl titanate, and 0.684g of antimony trichloride to 50mL of deionized water and stir until the solution turns pure white.

[0029] 2) Weigh 0.2g of coal tar pitch-based spherical activated carbon PSAC and place it on top of the FOSS crucible. Heat the reactor. Specifically, place the FOSS crucible in a polytetrafluoroethylene liner and place a weighing bottle containing 3ml of concentrated nitric acid underneath. Seal the high-pressure reactor and maintain it at 160℃ for 4 hours. Allow it to cool naturally to room temperature, rinse with deionized water until neutral, and air dry for 24 hours.

[0030] 3) Take 0.3g of the dried coal tar pitch-based spherical activated carbon from step 2) and add it to the pure white solution obtained in step 1). Continue stirring, and finally add 0.5g of sodium hydroxide. After stirring for 1 hour, place it in a high-pressure reactor and maintain it at 100℃ for 12 hours. After natural cooling, centrifuge the mixture, wash it 3-5 times with deionized water and anhydrous ethanol, and dry it in a drying oven at 150℃ to obtain the TiO2 / Sb2O3 / PSAC-3 composite material.

[0031] Depend on Figure 2 As can be seen, all the characteristic diffraction peaks of the sample correspond to the characteristic peaks of Sb2O3 and TiO2. No diffraction peaks of other substances were observed in the XRD pattern, which indicates that the prepared material is relatively pure and free of other impurities.

[0032] To determine the valence state and electronic environment of each element in the TiO2 / Sb2O3 / PSAC-3 photocatalyst, XPS analysis was performed. The results are as follows: Figure 3 As shown. By Figure 3 (a) The full spectrum of the material shows that the TiO2 / Sb2O3 / PSAC-3 composite material contains elements such as Ti, O, Sb, and C (the carbon element in TiO2 / Sb2O3 may come from the conductive adhesive carbon substrate). Figure 3 (b) shows the fine Ti 2p spectrum of the TiO2 / Sb2O3 / PSAC-3 composite material. As can be seen from the figure, at 458.8 eV (Ti 2p... 2 / 3 ) and 464.5eV (Ti2p 1 / 2 The appearance of characteristic splitting peaks with a spacing of 5.7 eV in Ti 2p can be attributed to Ti 4+ The presence of (TiO2). Figure 3 (c) shows the O1s fine spectrum of the TiO2 / Sb2O3 / PSAC-3 composite material. The peak around 527.2 eV is attributed to oxygen atoms bonded to Sb-O and Ti-O in the ternary composite material, while the peak around 529.3 eV may be related to the presence of hydroxyl groups on the material surface. Furthermore, Figure 3 (d) shows the fine Sb 3d spectrum of the TiO2 / Sb2O3 / PSAC-3 composite material. As can be seen from the figure, the two characteristic split peaks with a spacing of 9.7 eV at 539.96 and 530.26 eV belong to the Sb 3d spectrum of Sb2O3. 3 / 2 and Sb 3d 5 / 2 The orbital peaks demonstrate the presence of Sb₂O₃ material in the TiO₂ / Sb₂O₃ / PSAC-3 composite material. Combined with the Ti 2p fine spectrum results, this indicates the presence of a TiO₂ / Sb₂O₃ heterojunction material within the TiO₂ / Sb₂O₃ / PSAC-3 composite material. These results are consistent with the aforementioned XRD and TEM measurements, further confirming the existence of the TiO₂ / Sb₂O₃ heterojunction material.

[0033] like Figure 4 As shown in (a), the TiO2 / Sb2O3 heterojunction material exhibits a large cluster structure overall, and as can be seen in Figure 4(b), the lattice fringes of the TiO2 and Sb2O3 materials are interwoven (circled or elliptical regions). HRTEM image ( Figure 4 (c) shows that the crystal plane with a lattice spacing of 0.346 nm is the (101) crystal plane of TiO2, and the surrounding crystal plane is the (012) crystal plane of Sb2O3 with a lattice spacing of 0.265 nm, indicating that the TiO2 / Sb2O3 heterojunction material was successfully prepared. The above results are consistent with the XRD results. In order to further observe the elemental distribution in the TiO2 / Sb2O3 material, elemental analysis of the TiO2 / Sb2O3 heterojunction material was performed using a high-angle annular dark-field (HAADF) scanning transmission electron microscope (STEM) with EDX elemental scanning. Figure 4 (d) The compositional profile of the composite material is clearly demonstrated, indicating that the heterojunction material is a homogeneous mixture of Sb₂O₃ and TiO₂, and confirming that O( Figure 4 (d) upper right figure), Sb( Figure 4 (d) lower left figure) and Ti( Figure 4 (d) shows the uniform distribution of elements in the heterojunction material.

[0034] Depend on Figure 5 (a) It can be seen that there are a large number of microporous structures in the material. These microporous structures can provide a large specific surface area, improve the adsorption performance of the composite material, and help the composite material adsorb fungal substances to the vicinity of the photocatalyst for sterilization.

[0035] See Figure 5 The specific surface area of ​​the TiO2 / Sb2O3 / PSAC-3 composite material is between 100 and 2549 m². 2 / g or more. The composite material exhibits high bactericidal efficiency under sunlight excitation. Statistical analysis of bacteria counts in water using the plate coating method revealed a significant reduction in bacterial count in solutions using the composite material, and the material maintained excellent bactericidal performance even after multiple uses.

[0036] Depend on Figure 6 It can be seen that the prepared TiO2 / Sb2O3 / PSAC-3 composite material has better bactericidal performance than simple coal tar pitch spherical activated carbon. Even after 5 cycles, it still maintains a 75% bactericidal rate.

[0037] When using the TiO2 / Sb2O3 / PSAC-3 heterojunction bactericidal composite material, a xenon lamp is used to simulate sunlight as the light source. Coal tar pitch-based composite activated carbon balls with TiO2 / Sb2O3 loaded on their surface are placed in koi breeding water at a ratio of 1 (mg): 10 (ml) and stirred. The bactericidal performance of TiO2 / Sb2O3 coal tar pitch-based spherical activated carbon can then be tested using a plate coating method.

[0038] Example 2

[0039] See Figure 1 Preparation of TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material:

[0040] 1) Add 0.1g of hexadecyltrimethylammonium bromide, 2.4g of tetrabutyl titanate, and 0.228g of antimony trichloride to 50mL of deionized water and stir until the solution turns pure white.

[0041] 2) Weigh 0.2g of coal tar pitch-based spherical activated carbon PSAC and place it on top of the FOSS crucible. Heat the reactor. Specifically, place the FOSS crucible in a polytetrafluoroethylene liner and place a weighing bottle containing 3ml of concentrated nitric acid underneath. Seal the high-pressure reactor and maintain it at 160℃ for 4 hours. Allow it to cool naturally to room temperature, rinse with deionized water until neutral, and air dry for 24 hours.

[0042] 3) Take 0.3g of the dried coal tar pitch-based spherical activated carbon from step 2) and add it to the pure white solution obtained in step 1). Continue stirring, and finally add 0.5g of sodium hydroxide. After stirring for 1 hour, place it in a high-pressure reactor and maintain it at 100℃ for 12 hours. After natural cooling, centrifuge and wash with deionized water and anhydrous ethanol 3-5 times respectively. Dry in a drying oven at 150℃ to obtain the TiO2 / Sb2O3 / PSAC-1 composite material.

[0043] Depend on Figure 2 As can be seen, all the characteristic diffraction peaks of the sample correspond to the characteristic peaks of Sb2O3 and TiO2. No diffraction peaks of other substances were observed in the XRD pattern, which indicates that the prepared material is relatively pure and free of other impurities.

[0044] To determine the valence state and electronic environment of each element in the TiO2 / Sb2O3 / PSAC-1 photocatalyst, XPS testing was performed. The results are as follows: Figure 3 As shown. By Figure 3 (a) The full spectrum of the material shows that the TiO2 / Sb2O3 / PSAC-1 composite material contains elements such as Ti, O, Sb, and C. Figure 3 (b) shows the fine Ti 2p spectrum of the TiO2 / Sb2O3 / PSAC-1 composite material. As can be seen from the figure, at 458.8 eV (Ti 2p... 2 / 3 ) and 464.5eV (Ti 2p 1 / 2 The appearance of characteristic splitting peaks with a spacing of 5.7 eV in Ti 2p can be attributed to Ti 4+ The presence of (TiO2). Figure 3 (c) shows the O1s fine spectrum of the TiO2 / Sb2O3 / PSAC-1 composite material. The peak around 527.2 eV is attributed to oxygen atoms bonded to Sb-O and Ti-O in the ternary composite material, while the peak around 529.3 eV may be related to the presence of hydroxyl groups on the material surface. Furthermore, Figure 3 (d) shows the fine Sb 3d spectrum of the TiO2 / Sb2O3 / PSAC-1 composite material. As can be seen from the figure, the two characteristic split peaks with a spacing of 9.7 eV at 539.96 and 530.26 eV belong to the Sb 3d spectrum of Sb2O3. 3 / 2 and Sb 3d 5 / 2 The orbital peaks demonstrate the presence of Sb₂O₃ in the TiO₂ / Sb₂O₃ / PSAC-1 composite material. Combined with the Ti 2p fine spectrum results, this indicates the presence of a TiO₂ / Sb₂O₃ heterojunction within the TiO₂ / Sb₂O₃ / PSAC-1 composite material. These results are consistent with the aforementioned XRD and TEM measurements, further confirming the existence of the TiO₂ / Sb₂O₃ heterojunction material.

[0045] And by Figure 6 It can be seen that the prepared TiO2 / Sb2O3 / PSAC-1 composite material has better bactericidal performance than simple coal tar pitch spherical activated carbon. Even after 5 cycles, it still maintains a bactericidal rate of 67%.

[0046] Example 3

[0047] See Figure 1 Preparation of TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material:

[0048] 1) Add 0.1g of hexadecyltrimethylammonium bromide, 2.4g of tetrabutyl titanate, and 0.456g of antimony trichloride to 50mL of deionized water and stir until the solution turns pure white.

[0049] 2) Weigh 0.2g of coal tar pitch-based spherical activated carbon PSAC and place it on top of the FOSS crucible. Heat the reactor. Specifically, place the FOSS crucible in a polytetrafluoroethylene liner and place a weighing bottle containing 3ml of concentrated nitric acid underneath. Seal the high-pressure reactor and maintain it at 160℃ for 4 hours. Allow it to cool naturally to room temperature, rinse with deionized water until neutral, and air dry for 24 hours.

[0050] 3) Take 0.3g of the dried coal tar pitch-based spherical activated carbon from step 2) and add it to the pure white solution obtained in step 1). Continue stirring, and finally add 0.5g of sodium hydroxide. After stirring for 1 hour, place it in a high-pressure reactor and maintain it at 100℃ for 12 hours. After natural cooling, centrifuge and wash with deionized water and anhydrous ethanol 3-5 times respectively. Dry in a drying oven at 150℃ to obtain the TiO2 / Sb2O3 / PSAC-2 composite material.

[0051] Depend on Figure 2 As can be seen, all the characteristic diffraction peaks of the sample correspond to the characteristic peaks of Sb2O3 and TiO2. No diffraction peaks of other substances were observed in the XRD pattern, which indicates that the prepared material is relatively pure and free of other impurities.

[0052] To determine the valence state and electronic environment of each element in the TiO2 / Sb2O3 / PSAC-2 photocatalyst, XPS analysis was performed. The results are as follows: Figure 3 As shown. By Figure 3 (a) The full spectrum of the material shows that the TiO2 / Sb2O3 / PSAC-2 composite material contains elements such as Ti, O, Sb, and C. Figure 3 (b) shows the fine Ti 2p spectrum of the TiO2 / Sb2O3 / PSAC-2 composite material. As can be seen from the figure, at 458.8 eV (Ti 2p... 2 / 3 ) and 464.5eV (Ti 2p 1 / 2 The appearance of characteristic splitting peaks with a spacing of 5.7 eV in Ti 2p can be attributed to Ti 4+ The presence of (TiO2). Figure 3 (c) shows the O1s fine spectrum of the TiO2 / Sb2O3 / PSAC-2 composite material. The peak around 527.2 eV is attributed to oxygen atoms bonded to Sb-O and Ti-O in the ternary composite material, while the peak around 529.3 eV may be related to the presence of hydroxyl groups on the material surface. Furthermore, Figure 3(d) shows the fine Sb 3d spectrum of the TiO2 / Sb2O3 / PSAC-2 composite material. As can be seen from the figure, the two characteristic split peaks with a spacing of 9.7 eV at 539.96 and 530.26 eV belong to the Sb 3d spectrum of Sb2O3. 3 / 2 and Sb 3d 5 / 2 The orbital peaks demonstrate the presence of Sb₂O₃ in the TiO₂ / Sb₂O₃ / PSAC-2 composite material. Combined with the Ti 2p fine spectrum results, this indicates the presence of a TiO₂ / Sb₂O₃ heterojunction within the composite material. These results are consistent with the aforementioned XRD and TEM measurements, further confirming the existence of the TiO₂ / Sb₂O₃ heterojunction.

[0053] And by Figure 6 It can be seen that the prepared TiO2 / Sb2O3 / PSAC-2 composite material has better bactericidal performance than simple coal tar pitch spherical activated carbon. Furthermore, after 5 cycles, it still maintains a 65% bactericidal rate.

[0054] Example 4

[0055] Replacing antimony trichloride with antimony pentachloride in the above examples still yields similar results.

[0056] This invention addresses two main issues. First, it utilizes heterojunction materials to mitigate the low sterilization rate of nano-titanium dioxide, thereby improving the utilization of sunlight and inhibiting the recombination of photogenerated electrons and holes, thus enhancing the photocatalytic efficiency of nano-titanium dioxide. Second, it loads the heterojunction material TiO2 / Sb2O3 onto spherical activated carbon made from coal tar pitch, effectively increasing the specific surface area of ​​the material and improving its adsorption performance. The TiO2 / Sb2O3 / PSAC heterojunction sterilization composite material prepared using this method can be used for sterilization treatment of aquaculture water, exhibiting excellent sterilization performance, and the prepared material demonstrates good recyclability.

Claims

1. A method for preparing a TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material, characterized in that, Includes the following steps: 1) Add 0.01-0.15g of cationic surfactant, 1.5-3g of tetrabutyl titanate, and 0.2-0.9g of antimony trichloride or antimony pentachloride to 40-80mL of deionized water and stir until the solution turns pure white; 2) Weigh 0.1-0.3g of coal tar pitch-based spherical activated carbon and place it on top of the FOSS crucible. Then place the FOSS crucible in a high-pressure reactor containing concentrated nitric acid, heat to 150-180℃, maintain for 2-5 hours, cool naturally to room temperature, rinse with deionized water until neutral, and air dry naturally; the concentrated nitric acid is 1-4 ml. 3) Place the dried coal tar pitch-based spherical activated carbon into the pure white solution obtained in step 1), stir for 10-30 min, and finally add 0.3-0.6 g of sodium hydroxide. After stirring for 0.5-1.5 h, place it in a high-pressure reactor and maintain it at 80-120℃ for 10-14 h. After natural cooling, centrifuge the mixture and wash it 3-5 times with deionized water and anhydrous ethanol, respectively. Finally, dry the mixture to obtain the TiO2 / Sb2O3 / PSAC composite material. The cationic surfactant is one of hexadecyltrimethylammonium bromide, dodecyldimethylbenzylammonium chloride, hexadecyltrimethylammonium chloride, and octadecyltrimethylammonium chloride.

2. The method for preparing a TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material according to claim 1, characterized in that, In step 2), the FOSS crucible is placed inside the polytetrafluoroethylene liner of the high-pressure reactor, and a weighing bottle containing concentrated nitric acid is placed underneath it. The high-pressure reactor is then sealed.

3. The method for preparing a TiO2 / Sb2O3 / PSAC heterojunction antibacterial composite material according to claim 1, characterized in that, The pH value of the solution described in step 1) is ≥10.

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