CN111573773B - Application of titanium-based coordination polymer in photocatalytic degradation of dye wastewater - Google Patents

Abstract

The present invention belongs to the application of crystal materialThe technical field, in particular to application of a titanium-based coordination polymer in photocatalytic degradation of dye wastewater. The concentration of the titanium-based coordination polymer material pair is 2 multiplied by 10 ^‑4 Degrading with mol/L methylene blue, rhodamine B and methyl orange water solution, wherein the degradation rate reaches 100% in 8min, 12min and 8min respectively; for the concentration of 3X 10 ^‑4 Degrading methylene blue, rhodamine B and methyl orange water solution in mol/L, wherein the degradation rate reaches 100% in 16min, 24min and 17min respectively; for concentration of 4X 10 ^{‑ 4} The degradation rates of the mol/L methylene blue, rhodamine B and methyl orange aqueous solutions reach 100% in 25min, 38min and 27min respectively, and the titanium-based coordination polymer material has the characteristics of high degradation efficiency, thorough degradation product, no secondary pollution, cyclic utilization and the like in a dye wastewater degradation test, and has wide application prospects in the field of water pollution treatment.

Description

Application of a titanium-based coordination polymer in photocatalytic degradation of dye wastewater

technical field

The invention belongs to the technical field of crystal material application, in particular to the application of a titanium-based coordination polymer in photocatalytic degradation of dye wastewater.

Background technique

With the rapid development of my country's economic construction, the waste water produced by the manufacturing industry has increased year by year, and the resulting water environment pollution problem has become increasingly serious. Among them, textile pollution is one of the important culprits of water pollution. Dye wastewater has the characteristics of complex composition, deep chroma, large changes in water quality, and poor biodegradability. It is one of the more difficult wastewaters to treat. Photocatalysis technology can use light energy to oxidize and decompose organic pollutants, and it is an important method to treat various dye wastewater. Nano-titanium dioxide (TiO ₂ ) is considered to be one of the most promising photocatalysts due to its low cost, high efficiency and environmental friendliness. However, this type of _TiO2 material also has some shortcomings that cannot be ignored, such as wide energy band gap, fast photogenerated electron-hole pair recombination rate, and short photogenerated carrier lifetime, etc. These factors seriously limit its use in photocatalysis. practical applications in the field.

Titanium-based coordination polymers have become one of the most attractive coordination polymers reported so far due to their promising application in photocatalysis. Compared with semiconducting _TiO photocatalytic materials, titanium-based coordination polymers have many advantages, such as precise atomic-level structural information, well-defined ligand-cluster-nucleus connection, tunable topology, and ease of modification. However, the research on titanium-based coordination polymers has been in its infancy, and less research has been done on its application in dye wastewater treatment. In view of this, the use of titanium-based coordination polymers for photocatalytic degradation of dye wastewater has become an important research topic.

SUMMARY OF THE INVENTION

In order to overcome the defects of the prior art, the present invention provides an application of a titanium-based coordination polymer in photocatalytic degradation of dye wastewater, and the titanium-based coordination polymer material shows degradation efficiency in the photodegradation dye wastewater degradation test. High, complete degradation products, no secondary pollution, recyclable and other characteristics.

To achieve the above object, the technical scheme adopted in the present invention is:

The application of a titanium-based coordination polymer in photocatalytic degradation of dye wastewater is characterized in that the titanium-based coordination polymer material degrades methylene blue, rhodamine B and methyl orange aqueous solutions.

Further, the photocatalytic degradation of dye waste water adopts the following steps: dispersing the titanium-based coordination polymer in the dye aqueous solution, and placing it under a 300W xenon lamp equipped with a filter (>420nm) for illumination, With continuous stirring, 2 mL of the solution was taken out every 2 min, filtered, and the solution was analyzed by an ultraviolet absorption spectrometer.

Further, the ratio of the amount of the added titanium-based coordination polymer and the amount of methylene blue substances in the dye wastewater is: 1: (2~4); the added titanium-based coordination polymer and the rhodamine in the dye wastewater are: The ratio of the amount of substance B is: 1: (2~4); the ratio of the amount of the added titanium-based coordination polymer and the amount of methyl orange in the dye wastewater is: 1: (2~4).

The molecular formula of a titanium oxide cluster coordination polymer is Ti ₃ O ₁₂ C ₃₀ N ₃ H ₄₇ CuBr.

Further, the crystal structure of the titanium-based coordination polymer is: the crystal belongs to the monoclinic system, the space group is C2/ c , the unit cell parameters are a=17.3730Å, b=19.2330Å, c=18.5000Å, α =90°, β=109°, γ=90°.

Further, the titanium-based coordination polymer was synthesized by the following steps: adding isopropyl titanate, cuprous bromide, isonicotinic acid ligand and acetonitrile solvent into the reaction kettle, stirring at room temperature for 0.5-1.5 h, and stirring at room temperature for 80-10 h. The reaction was carried out at 120° C. for 48-96 hours, and the temperature was lowered to 25° C. to precipitate massive crystals in the system, which were separated, washed and dried to obtain the titanium-based coordination polymer.

Further, the mass-volume ratio of the isopropyl titanate, cuprous bromide, isonicotinic acid ligand and acetonitrile solvent is: (0.1~0.2) mL: (0.15~0.20) g: 0.1 g: (4 ~6) mL.

Further, the cooling is carried out by means of programmed temperature control, and the cooling rate is controlled at 3-10° C./h; the washing is three times with isopropanol; and the drying is natural drying.

beneficial effect

The invention provides the application of a titanium-based coordination polymer in photocatalytic degradation of dye wastewater. The titanium-based coordination polymer material has high degradation efficiency, complete degradation products, no secondary pollution, Recyclable features.

Description of drawings

Figure 1 is a structural diagram of a titanium-based coordination polymer;

Fig. 2 is embodiment 1 photocatalytic degradation methylene blue test chart;

Fig. 3 is embodiment 2 photocatalytic degradation Rhodamine B test chart;

Fig. 4 is embodiment 3 photocatalytic degradation methyl orange test chart;

Figure 5 is a cycle test diagram of photocatalytic degradation of methylene blue, rhodamine B and methyl orange in Examples 1-3.

Detailed ways

The present invention is described below through specific embodiments. Unless otherwise specified, the technical means used in the present invention are methods known to those skilled in the art. In addition, the embodiments are to be understood as illustrative, rather than limiting, of the scope of the invention, the spirit and scope of the invention being limited only by the claims. For those skilled in the art, on the premise of not departing from the spirit and scope of the present invention, various changes or modifications to the material components and dosages in these embodiments also belong to the protection scope of the present invention. The raw materials and reagents used in the present invention are commercially available.

In order to make the objects and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the embodiments.

Example 1

Disperse 10 mg of titanium-based coordination polymer in 100 mL of methylene blue aqueous solution (2×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) for continuous irradiation And stirring, take out 2mL solution every 2min, filter, analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The methylene blue solution is completely degraded in 8 minutes, and the three cycle experiments show good photocatalytic degradation performance.

Example 2

Disperse 10 mg of titanium-based coordination polymer in 100 mL of Rhodamine B aqueous solution (2×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) Continue to irradiate and stir, take out 2 mL of the solution every 2 min, filter, and analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases with the increase of the reaction time. No new absorption peak appears in the entire measurement band. The Rhodamine B solution was completely degraded in 12 minutes. The three cycle experiments showed good photocatalytic degradation performance. .

Example 3

Disperse 10 mg of titanium-based coordination polymer in 100 mL of methyl orange aqueous solution (2 × 10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) Continue to irradiate and stir, take out 2 mL of the solution every 2 min, filter, and analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The methyl orange solution is completely degraded in 8 minutes. The three cycle experiments show good photocatalytic degradation performance. .

Example 4

Disperse 10 mg of titanium-based coordination polymer in 100 mL of methylene blue aqueous solution (3×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) for continuous irradiation And stirring, take out 2mL solution every 2min, filter, analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum curve gradually decreases with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The methylene blue solution is completely degraded in 16 minutes, and the three cycle experiments show good photocatalytic degradation performance.

Example 5

Disperse 10 mg of titanium-based coordination polymer in 100 mL of Rhodamine B aqueous solution (3×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) Continue to irradiate and stir, take out 2 mL of the solution every 2 min, filter, and analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum curve gradually decreases with the increase of reaction time, and no new absorption peak appears in the entire measurement band. The 25min Rhodamine B solution is completely degraded, and the three cycle experiments show good photocatalytic degradation performance. .

Example 6

Disperse 10 mg of the titanium-based coordination polymer in 100 mL of methyl orange aqueous solution (3×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) Continue to irradiate and stir, take out 2 mL of the solution every 2 min, filter, and analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The methyl orange solution is completely degraded in 17 minutes. The three cycle experiments show good photocatalytic degradation performance. .

Example 7

Disperse 10 mg of titanium-based coordination polymer in 100 mL of methylene blue aqueous solution (4×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) for continuous irradiation And stirring, take out 2mL solution every 2min, filter, analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases gradually with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The methylene blue solution is completely degraded in 25 minutes. The three cycle experiments show good photocatalytic degradation performance.

Example 8

Disperse 10 mg of titanium-based coordination polymer in 100 mL of Rhodamine B aqueous solution (4×10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) Continue to irradiate and stir, take out 2 mL of the solution every 2 min, filter, and analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The Rhodamine B solution is completely degraded in 38 minutes, and the three cycle experiments show good photocatalytic degradation performance. .

Example 9

Disperse 10 mg of titanium-based coordination polymer in 100 mL of methyl orange aqueous solution (4 × 10 ^-4 mol/L), stir continuously for 2 h in the dark to achieve adsorption saturation, and then place it under a 300W xenon lamp (>420 nm) Continue to irradiate and stir, take out 2 mL of the solution every 2 min, filter, and analyze by ultraviolet absorption spectrometer. The test results are shown in Figure 2. The peak height of the UV absorption spectrum decreases with the increase of the reaction time. There is no new absorption peak in the entire measurement band. The methyl orange solution is completely degraded in 27 minutes. The three cycle experiments show good photocatalytic degradation performance. .

The titanium-based coordination polymers of the above examples 1-9 used for photodegradation of dye wastewater, the molecular formula of the titanium oxide cluster-based coordination polymers is Ti ₃ O ₁₂ C ₃₀ N ₃ H ₄₇ CuBr; The crystal structure of the position polymer is: the crystal belongs to the monoclinic system, the space group is C2/c , and the unit cell parameters are a=17.3730Å, b=19.2330Å, c=18.5000Å, α=90°, β=109°, γ=90°.

Titanium-based coordination polymer materials are used for photocatalytic degradation of dye wastewater. The test results show that the titanium-based coordination polymer materials can degrade 2×10 ^-4 mol/L methylene blue, rhodamine B and methyl orange aqueous solutions, and the degradation rates reach 100% at 8min, 12min, and 8min respectively; 3×10 ^-4 mol/L methylene blue, rhodamine B and methyl orange aqueous solutions were degraded, and the degradation rate reached 100% in 16min, 25min and 17min respectively; 4×10 ^-4 mol/L methylene blue, rhodamine B , methyl orange aqueous solution was degraded, and the degradation rate reached 100% at 25min, 38min, and 27min respectively (Figure 2, 3, 4). Three cycle tests showed that the photocatalytic material has long-lasting photocatalytic activity and good photostability ( Figure 5). The titanium-based coordination polymer material has the characteristics of high degradation efficiency, complete degradation products, no secondary pollution, recyclability and the like in the dye wastewater degradation test, and has broad application prospects in the field of water pollution treatment.

Claims (6)

1. the application of a titanium-based coordination polymer in photocatalytic degradation dye wastewater, is characterized in that, described titanium-based coordination polymer material degrades methylene blue, rhodamine B, methyl orange aqueous solution; The molecular formula of the base coordination polymer is Ti ₃ O ₁₂ C ₃₀ N ₃ H ₄₇ CuBr; the crystal structure of the titanium base coordination polymer is: the crystal belongs to the monoclinic system, the space group is C2/c, and the unit cell parameter are a=17.3730 Å, b=19.2330 Å, c=18.5000 Å, α=90°, β=109°, γ=90°. 2. application according to claim 1, is characterized in that, described photocatalytic degradation of dye waste water, adopts following steps: disperse titanium-based coordination polymer in dye aqueous solution, and it is placed in with filter. The light sheet (>420 nm) was illuminated under a 300 W xenon lamp, stirred continuously, 2 mL of the solution was taken out, filtered, and the solution was analyzed by an ultraviolet absorption spectrometer. 3. The application according to claim 2, wherein the ratio of the added titanium-based coordination polymer and the amount of methylene blue in the dye wastewater is: 1: (2-4); the added The ratio of the amount of rhodamine B in the titanium-based coordination polymer and the dye wastewater is: 1: (2-4); the ratio of the added titanium-based coordination polymer and the amount of methyl orange in the dye wastewater is: 1:(2-4). 4. The application according to any one of claims 1-3, wherein the titanium-based coordination polymer adopts the following steps to synthesize: by isopropyl titanate, cuprous bromide, isonicotinic acid ligand and acetonitrile The solvent was added to the reaction kettle, stirred at room temperature for 0.5-1.5 h, reacted at 80-120 °C for 48-96 h, cooled to 25 °C, and massive crystals were precipitated in the system, which was separated, washed and dried to obtain the titanium-based compound. bit polymer. 5. application according to claim 4 is characterized in that, the mass volume ratio of described isopropyl titanate, cuprous bromide, isonicotinic acid ligand and acetonitrile solvent is: (0.1-0.2) mL: (0.15-0.20) g: 0.1 g: (4-6) mL. 6. application according to claim 4, is characterized in that, described cooling adopts the mode of program temperature control to carry out, and cooling rate is controlled at 3-10 ℃/h; Described washing is to adopt isopropanol to wash three times; The drying is natural drying.

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