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CN-121972184-A - Manganese ferrite/zinc gallate heterojunction photocatalyst and preparation method and application thereof

CN121972184ACN 121972184 ACN121972184 ACN 121972184ACN-121972184-A

Abstract

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a manganese ferrite/zinc gallate heterojunction photocatalyst, and a preparation method and application thereof. The preparation method comprises the following steps of 1) dissolving zinc acetate and gallium nitrate hydrate in deionized water, then adding citric acid monohydrate, obtaining zinc gallate by a sol-gel method, 2) dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in deionized water, then adding a sodium hydroxide solution, obtaining manganese ferrite by a hydrothermal method, and 3) dissolving zinc gallate and manganese ferrite in a methanol solution, and obtaining the manganese ferrite/zinc gallate heterojunction photocatalyst by a mechanical stirring method. The formation of heterojunction can greatly improve the activity of photocatalytic reduction of carbon dioxide of manganese ferrite/zinc gallate.

Inventors

  • KONG LINGRU
  • QIU SHI

Assignees

  • 辽宁大学

Dates

Publication Date
20260505
Application Date
20260401

Claims (9)

  1. 1. The manganese ferrite/zinc gallate heterojunction photocatalyst is characterized in that the molar ratio of manganese ferrite to the total amount of the manganese ferrite/zinc gallate heterojunction photocatalyst is 1:10, 2:10 or 3:10.
  2. 2. The method for preparing the manganese ferrite/zinc gallate heterojunction photocatalyst as claimed in claim 1, which is characterized by comprising the following steps: 1) Preparing zinc gallate by sol-gel method, namely dissolving zinc acetate and gallium nitrate hydrate in deionized water, adding citric acid monohydrate, stirring, heating and continuously stirring to form transparent sol, drying the transparent sol to obtain a precursor, calcining the precursor, and cooling to room temperature to obtain zinc gallate; 2) Preparing manganese ferrite by a hydrothermal method, namely dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in deionized water, stirring for 30 minutes, then dropwise adding 8mol/L sodium hydroxide solution while continuously stirring for 1 hour; 3) The manganese ferrite/zinc gallate heterojunction photocatalyst is prepared by a mechanical stirring method, namely, zinc gallate and manganese ferrite are dissolved into a methanol solution, and after ultrasonic treatment, stirring and drying are carried out, thus obtaining the manganese ferrite/zinc gallate heterojunction photocatalyst.
  3. 3. The method for preparing a manganese ferrite/zinc gallate heterojunction photocatalyst as claimed in claim 2, wherein in step 1), zinc acetate is gallium nitrate hydrate and citric acid monohydrate= 2 mmol:4 mmol:6 mmol.
  4. 4. The method for preparing the manganese ferrite/zinc gallate heterojunction photocatalyst according to claim 2, wherein in the step 1), the temperature is raised to 80 ℃ and stirring is continued for 5 hours, the drying temperature is 120 ℃, the calcining temperature is 500 ℃, and the calcining time is 5 hours.
  5. 5. The method for preparing the manganese ferrite/zinc gallate heterojunction photocatalyst according to claim 2, wherein in the step 2), ferric chloride hexahydrate, manganese chloride tetrahydrate, 8mol/L sodium hydroxide solution = 2.7029g:0.9892g:10mL.
  6. 6. The method for preparing the manganese ferrite/zinc gallate heterojunction photocatalyst according to claim 2, wherein in the step 2), the hydrothermal reaction temperature is 180 ℃, and the hydrothermal reaction time is 10 hours.
  7. 7. The method for preparing a manganese ferrite/zinc gallate heterojunction photocatalyst according to claim 2, wherein in step 3), the ultrasonic time is 45min, and the stirring time is 24h.
  8. 8. The use of a manganese ferrite/zinc gallate heterojunction photocatalyst as defined in claim 1 in the photocatalytic reduction of carbon dioxide.
  9. 9. The application of the manganese ferrite/zinc gallate heterojunction photocatalyst in photocatalytic reduction of carbon dioxide according to claim 8, wherein the application method is that the manganese ferrite/zinc gallate heterojunction photocatalyst and 1mL of deionized water are placed in a closed space filled with carbon dioxide gas under irradiation of visible light, and the carbon dioxide gas is reduced into carbon monoxide gas.

Description

Manganese ferrite/zinc gallate heterojunction photocatalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of photocatalytic materials, and particularly relates to a manganese ferrite/zinc gallate heterojunction photocatalyst, and a preparation method and application thereof. Background The photocatalytic carbon dioxide reduction takes inexhaustible solar energy as energy, can directly convert carbon dioxide gas into hydrocarbon solar fuel, and is a feasible method for simultaneously solving energy crisis and environmental pollution. Zinc gallate (ZnGa 2O4) is a typical broad band gap spinel type composite oxide and is widely focused on in the scientific research field as a novel photocatalytic material. The crystal structure of spinel is formed by ordered arrangement of tetrahedrally coordinated Zn 2+, octahedral coordinated Ga 3+ and O 2-, and the occupation characteristic of cations in crystal lattice can regulate and control the crystal field environment and the electronic structure. The spinel type three-dimensional framework structure can effectively shorten the transmission path of a photo-generated carrier, inhibit the recombination of the photo-generated carrier and endow the photo-generated carrier with excellent photochemical stability due to the wide forbidden band characteristic. However, the pure-phase zinc gallate has a narrow photoresponse range, only absorbs ultraviolet light, has insufficient separation efficiency of photo-generated electron-hole pairs, and limits the practical application of the pure-phase zinc gallate in the field of visible light photocatalysis. Therefore, manganese ferrite (MnFe 2O4) has wide photocatalytic application due to the narrow band gap, excellent photochemical stability and environmental friendliness, and can be compositely constructed with ZnGa 2O4 to form a heterostructure. Manganese ferrite is also a transition metal oxide, and active metal sites are introduced, so that the adsorption of ZnGa 2O4 on carbon dioxide can be enhanced. The separation efficiency of carriers can be improved by constructing the manganese ferrite/zinc gallate heterojunction, so that the aim of improving the photocatalytic activity of ZnGa 2O4 is fulfilled. Disclosure of Invention The invention provides a manganese ferrite/zinc gallate heterojunction photocatalyst, a preparation method and application thereof aiming at the defects existing in the prior art, the method is simple, convenient, low in cost, mild in condition and beneficial to large-scale production, and the obtained manganese ferrite/zinc gallate heterojunction photocatalyst has good photocatalytic reduction carbon dioxide activity. The technical scheme adopted by the invention is as follows: A manganese ferrite/zinc gallate heterojunction photocatalyst, wherein the molar ratio of manganese ferrite to the total amount of manganese ferrite/zinc gallate heterojunction photocatalyst is 1:10, 2:10 or 3:10. The preparation method of the manganese ferrite/zinc gallate heterojunction photocatalyst comprises the following steps: 1) Preparing zinc gallate by sol-gel method, namely dissolving zinc acetate and gallium nitrate hydrate in deionized water, adding citric acid monohydrate, stirring, heating and continuously stirring to form transparent sol, drying the transparent sol to obtain a precursor, calcining the precursor, and cooling to room temperature to obtain zinc gallate; 2) Preparing manganese ferrite by a hydrothermal method, namely dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in deionized water, stirring for 30 minutes, then dropwise adding 8mol/L sodium hydroxide solution while continuously stirring for 1 hour; 3) The manganese ferrite/zinc gallate heterojunction photocatalyst is prepared by a mechanical stirring method, namely, zinc gallate and manganese ferrite are dissolved into a methanol solution, and after ultrasonic treatment, stirring and drying are carried out, thus obtaining the manganese ferrite/zinc gallate heterojunction photocatalyst. Further, in the preparation method of the manganese ferrite/zinc gallate heterojunction photocatalyst, in the step 1), zinc acetate is gallium nitrate hydrate, and citric acid monohydrate= 2 mmol:4 mmol:6 mmol. Further, in the preparation method of the manganese ferrite/zinc gallate heterojunction photocatalyst, in the step 1), the temperature is raised to 80 ℃ and stirring is continued for 5 hours, the drying temperature is 120 ℃, the calcining temperature is 500 ℃, and the calcining time is 5 hours. Further, in the preparation method of the manganese ferrite/zinc gallate heterojunction photocatalyst, in the step 2), ferric chloride hexahydrate, manganese chloride tetrahydrate, 8mol/L sodium hydroxide solution=2.7029 g, 0.9892g and 10mL are adopted. Further, in the preparation method of the manganese ferrite/zinc gallate heterojunction photocatalyst, in the step 2), the hydrothermal