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CN-121669322-B - TiO2MOFs photocatalyst and preparation method and application thereof

CN121669322BCN 121669322 BCN121669322 BCN 121669322BCN-121669322-B

Abstract

The invention relates to the technical field of photocatalysts, in particular to a TiO 2 -MOFs photocatalyst and a preparation method and application thereof, and the preparation method comprises the following steps of adding TiO 2 nano particles into deionized water, dispersing to obtain a solution A, adding modified MIL-88A/GO into the solution A to obtain a mixed solution, stirring the mixed solution, centrifuging and alternately washing with ethanol and deionized water, and freeze-drying to obtain the modified TiO 2 -MOFs photocatalyst. According to the invention, through compounding of TiO 2 nano particles and modified MIL-88A/GO, an adsorption-catalysis synergistic effect is realized, the modified MIL-88A/GO material has the characteristics of high specific surface area, porosity and controllable pore diameter, pollutants in organic wastewater can be efficiently adsorbed, a high-concentration reaction environment is provided for the photocatalytic reaction of TiO 2 nano particles, and TiO 2 nano particles serve as a high-efficiency photocatalyst, and the adsorbed pollutants can be rapidly oxidized and degraded by electron-hole pairs generated under photon excitation.

Inventors

  • HUANG WENXIU
  • ZHAO NANNAN
  • WANG WENHUI

Assignees

  • 廊坊师范学院

Dates

Publication Date
20260508
Application Date
20260206

Claims (9)

  1. The preparation method of the TiO 2 -MOFs photocatalyst is characterized by comprising the following steps of: s1, placing the synergistic coordination precursor solution in a 60-80 ℃ for reaction for 10-12 hours, centrifuging and alternately washing with ethanol and deionized water, and drying to obtain modified MIL-88A/GO; S2, adding TiO 2 nano-particles into deionized water, dispersing for 1-3 hours to obtain a solution A, and adding modified MIL-88A/GO into the solution A to obtain a mixed solution; S3, stirring the mixed solution for 2-4 hours, centrifuging and alternately washing with ethanol and deionized water, and drying to obtain the modified TiO 2 -MOFs photocatalyst; wherein the synergistic-coordination precursor solution is prepared by the steps of: S11, adding expandable graphite into modified mixed acid at 0-5 ℃, then adding potassium permanganate, mixing to obtain a reaction system, stirring the reaction system for 10-12h, adding hydrogen peroxide to obtain a suspension, stirring the suspension for 2-4h, centrifugally washing with deionized water until the pH value of the supernatant is 6-7, collecting precipitate, and drying the precipitate after washing to obtain modified GO; S12, mixing ferric trichloride hexahydrate, fumaric acid and terephthalic acid in proportion, adding the mixture into deionized water to prepare a precursor solution A, adding the modified GO prepared in the step S11 into the precursor solution A, and performing ultrasonic dispersion for 20-30min to obtain a synergistic coordination precursor solution; The modified mixed acid is prepared by the following steps: Mixing concentrated sulfuric acid and concentrated phosphoric acid to form mixed acid, adding sulfamic acid into the mixed acid, and stirring for 10-20min at 0-3 ℃ until the sulfamic acid is completely dissolved to obtain the amination modified mixed acid, wherein the mass ratio of the concentrated sulfuric acid to the concentrated phosphoric acid to the sulfamic acid is (9-11): 1 (2-4).
  2. 2. The method for preparing a TiO 2 -MOFs photocatalyst according to claim 1, wherein the TiO 2 nanoparticle is prepared by: S21, dissolving titanium isopropoxide in absolute ethyl alcohol, stirring for 20-30min to completely dissolve to obtain a solution B, adding tetrabutyl titanate coupling agent into the solution B, continuously stirring for 15min, adding octylamine, and stirring uniformly to obtain a precursor solution B; S22, refluxing the precursor solution B at 60-70 ℃ for 16-20 hours to obtain a modified precursor solution, filtering the modified precursor solution, drying at 50-70 ℃ for 2-4 hours to obtain modified precursor particles, and calcining the modified precursor particles at 300-600 ℃ for 2-4 hours in the atmosphere to obtain the TiO 2 nano particles.
  3. 3. The method for preparing the TiO 2 -MOFs photocatalyst according to claim 1, wherein in the step S2, the mass part ratio of TiO 2 nano particles to deionized water is1 (90-110), and the mass part ratio of TiO 2 nano particles to modified MIL-88A/GO is1 (1-3).
  4. 4. The method for preparing the TiO 2 -MOFs photocatalyst according to claim 1, wherein in the step S11, the mass part ratio of the expandable graphite to the modified mixed acid is 1 (214-288), the mass part ratio of the potassium permanganate to the expandable graphite is (6-7) 1, and the mass part ratio of the hydrogen peroxide to the potassium permanganate is (1.5-2.2) 1.
  5. 5. The method for preparing the TiO 2 -MOFs photocatalyst according to claim 1, wherein in the step S12, the mass ratio of ferric trichloride hexahydrate to fumaric acid to terephthalic acid is 2 (0.8-1.2) (0.1-0.5), the mass ratio of ferric trichloride hexahydrate to deionized water is 1 (28-34), and the mass ratio of ferric trichloride hexahydrate to modified GO is 5-8): 1.
  6. 6. The method for preparing the TiO 2 -MOFs photocatalyst according to claim 2, wherein in the step S21, the mass part ratio of the titanium isopropoxide to the absolute ethyl alcohol is 1 (8-12), the mass part ratio of the titanium isopropoxide to the tetrabutyl titanate coupling agent is (5-8): 1, and the mass part ratio of the titanium isopropoxide to the octylamine is 1 (1-1.2).
  7. 7. The method for preparing the TiO 2 -MOFs photocatalyst according to claim 1, wherein in each washing in the steps S1 and S3, the mass fraction ratio of ethanol to sediment is (5-10): 1, the mass fraction ratio of deionized water to sediment is (5-10): 1, and the washing is performed alternately for 3-4 times.
  8. 8. A TiO 2 -MOFs photocatalyst, characterized in that it is obtainable by a process according to any one of the preceding claims 1-7.
  9. 9. Use of the TiO 2 -MOFs photocatalyst according to claim 8 for degrading organic wastewater pollutants.

Description

TiO 2 -MOFs photocatalyst and preparation method and application thereof Technical Field The invention relates to the technical field of photocatalysts, in particular to a TiO 2 -MOFs photocatalyst and a preparation method and application thereof. Background Along with rapid development of technology, the discharge amount of industrial wastewater is more and more, toxic and harmful substances in water body is complex, water treatment difficulty is higher and more, the photocatalytic technology has the advantages of strong oxidization and low energy consumption and the like, the photocatalytic technology has high efficiency in oxidative degradation of toxic and harmful substances, in recent years, research of the photocatalytic technology has greatly progressed, when photons with band gap energy equal to or larger than that of the semiconductor are excited, electrons are transferred from valence bands to conduction bands and form holes, if recombination does not occur, the electrons and the holes transferred to the surface of the semiconductor can reduce/oxidize adsorbed substrates, metal-organic frameworks (MOFs) are porous net structures formed by taking central metal ions as nodes and organic ligands as components, and MOFs materials have various morphology structures, controllable and adjustable pore sizes and unique physical and chemical characteristics and are applied to a plurality of fields such as catalysis, environmental repair and the like. The catalyst represented by pure TiO 2 nanoparticles, tiO 2/P25 and the like has strong oxidizing property and photocatalytic activity, but has no porous structure and extremely weak adsorption capacity to organic pollutants. In practical industrial wastewater (low pollutant concentration and dispersed components), the surface of TiO 2 is difficult to form a high-concentration reaction environment, photo-generated electron-hole pairs are difficult to effectively contact with pollutants, so that the catalytic degradation efficiency is low, and the deep treatment requirement of the low-concentration pollutants cannot be met. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a TiO 2 -MOFs photocatalyst, a preparation method and application thereof, so as to solve the problems in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: The preparation method of the TiO 2 -MOFs photocatalyst comprises the following steps: s1, placing the synergistic coordination precursor solution in a 60-80 ℃ for reaction for 10-12 hours, centrifuging and alternately washing with ethanol and deionized water, and drying to obtain modified MIL-88A/GO; S2, adding TiO 2 nano-particles into deionized water, dispersing for 1-3 hours to obtain a solution A, and adding modified MIL-88A/GO into the solution A to obtain a mixed solution; S3, stirring the mixed solution for 2-4 hours, centrifuging and alternately washing with ethanol and deionized water, and drying to obtain the modified TiO 2 -MOFs photocatalyst; wherein the synergistic-coordination precursor solution is prepared by the steps of: S11, adding expandable graphite into modified mixed acid at 0-5 ℃, then adding potassium permanganate, mixing to obtain a reaction system, stirring the reaction system for 10-12h, adding hydrogen peroxide to obtain a suspension, stirring the suspension for 2-4h, centrifugally washing with deionized water until the pH value of the supernatant is 6-7, collecting precipitate, and drying the precipitate after washing to obtain modified GO; S12, mixing ferric trichloride hexahydrate, fumaric acid and terephthalic acid in proportion, adding the mixture into deionized water to prepare a precursor solution A, adding the modified GO prepared in S11 into the precursor solution A, and performing ultrasonic dispersion for 20-30min to obtain a synergistic coordination precursor solution. Further, the TiO 2 nano-particles are prepared by the following steps: S21, dissolving titanium isopropoxide in absolute ethyl alcohol, stirring for 20-30min to completely dissolve to obtain a solution B, adding tetrabutyl titanate coupling agent into the solution B, continuously stirring for 15min, adding octylamine, and stirring uniformly to obtain a precursor solution B; S22, refluxing the precursor solution B at 60-70 ℃ for 16-20 hours to obtain a modified precursor solution, filtering the modified precursor solution, drying at 50-70 ℃ for 2-4 hours to obtain modified precursor particles, and calcining the modified precursor particles at 300-600 ℃ for 2-4 hours in the atmosphere to obtain the TiO 2 nano particles. Further, the modified mixed acid is prepared by the following steps: Mixing concentrated sulfuric acid and concentrated phosphoric acid to form mixed acid, adding sulfamic acid into the mixed acid, and stirring for 10-20min at 0-3 ℃ until the sulfamic acid is completely dissolved to obtain the amination modifi