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CN-121988355-A - Quaternary nano heterojunction photocatalyst and preparation method and application thereof

CN121988355ACN 121988355 ACN121988355 ACN 121988355ACN-121988355-A

Abstract

The invention provides a quaternary nano heterojunction photocatalyst, a preparation method and application thereof, and relates to the technical field of environmental photocatalysis. The catalyst has a quaternary multistage core-shell structure, the core of the core-shell structure takes NaYF 4 as a framework material and is doped with Yb 3+ and Tm 3+ , I and Fe co-doped TiO 2 semiconductor particles form a continuous and uniform shell outside the core, and a composite active layer formed by BiOI and simple substance Bi grows on the surface of the shell. The catalyst can realize full spectrum energy conversion under natural light, and can efficiently degrade bisphenol A, orange II and other pollutants in wastewater. The method has the characteristics of strong full spectrum response, high carrier separation efficiency, good stability and the like. The synergistic enhancement is realized by integrating near infrared up-conversion of NaYF 4 to Yb and Tm, energy band regulation and control of I-Fe on TiO 2 and carrier separation function of BiOI/Bi, and finally the industrial wastewater containing nondegradable pollutants is efficiently treated under natural light.

Inventors

  • WANG BAIQI
  • ZHANG CHANGYUAN
  • ZHENG JING
  • WU YANG

Assignees

  • 天津医科大学

Dates

Publication Date
20260508
Application Date
20260407

Claims (10)

  1. 1. The quaternary nano heterojunction photocatalyst is characterized by comprising a quaternary multi-stage core-shell structure, wherein the core of the core-shell structure takes NaYF 4 as a framework material and is doped with Yb 3+ and Tm 3+ ; The I and Fe co-doped TiO 2 semiconductor particles form a continuous and uniform shell layer outside the core; And a composite active layer formed by BiOI and simple substance Bi grows on the surface of the shell layer.
  2. 2. The quaternary nano heterojunction photocatalyst of claim 1, wherein the molar ratio between the core and the shell is 1 (4-6); the molar ratio of the shell layer to the composite active layer is 1 (2-4).
  3. 3. The quaternary nano heterojunction photocatalyst of claim 1, wherein the molar ratio of the three elements of I, fe and Ti in the shell layer is 0.1:0.001:1.
  4. 4. The quaternary nano heterojunction photocatalyst of claim 1, wherein the molar ratio of the three elements of Y, yb, tm in the core is 79.5:20:0.5.
  5. 5. A method of preparing the quaternary nano heterojunction photocatalyst of any one of claims 1-4, comprising the steps of: S1, synthesizing a core by a hydrothermal method to obtain NaYF 4 Yb and Tm powder; s2, preparing NaYF 4 :Yb,Tm@I-Fe-TiO 2 powder by a sol method; S3, preparing NaYF 4 :Yb,Tm@I-Fe-TiO 2 /BiOI nano powder by a chemical precipitation method; S4, preparing the NaYF 4 :Yb,Tm@I-Fe-TiO 2 /BiOI/Bi quaternary nano heterojunction photocatalyst by a hydrothermal reduction method.
  6. 6. The method for preparing a quaternary nano heterojunction photocatalyst as claimed in claim 5, wherein said S1 specifically comprises: S101, stirring NaOH, oleic acid and absolute ethyl alcohol until the mixture is white and viscous, and then adding NaF solution while stirring until the solution is semitransparent; S102, adding YCl 3 、TmCl 3 and YbCl 3 solution into the semitransparent solution, continuously stirring to form semitransparent colloid, reacting for 10-15 h at a constant temperature of 150-200 ℃, cooling after the reaction is finished, centrifuging, and washing to obtain NaYF 4 :Yb and Tm powder.
  7. 7. The method for preparing a quaternary nano heterojunction photocatalyst as claimed in claim 5, wherein said S2 specifically comprises: S201, adding butyl titanate into ethanol, stirring, and then adding glacial acetic acid to uniformly mix to obtain a mixed solution A; s202, mixing absolute ethyl alcohol with an iodic acid solution and an iron nitrate solution, and regulating the pH value to 2.0 by using hydrochloric acid to obtain a mixed solution B; S203, ultrasonically dissolving the NaYF 4 Yb and Tm up-conversion nano-particles in cyclohexane, mixing with cetyltrimethylammonium bromide and deionized water, stirring the mixture to be milky, steaming the cyclohexane in a water bath at 80 ℃, cooling and centrifuging after the solution is clarified, and washing to obtain hydrophilic NaYF 4 Yb and Tm nano-particles; S204, mixing the NaYF 4 Yb and Tm nano-particles with the mixed solution A, dripping the mixed solution B, stirring, washing, centrifugally collecting the precipitate, drying, grinding and roasting to obtain NaYF 4 :Yb,Tm@I-Fe-TiO 2 powder.
  8. 8. The method for preparing a quaternary nano heterojunction photocatalyst as claimed in claim 5, wherein said S3 specifically comprises: S301, dissolving potassium iodide in deionized water to obtain a solution B; s302, adding NaYF 4 :Yb,Tm@I-Fe-TiO 2 powder and bismuth nitrate pentahydrate into ethylene glycol, and performing ultrasonic dissolution to obtain a solution A; S303, injecting the solution B into the solution A for reaction, and drying to obtain NaYF 4 :Yb,Tm@I-Fe-TiO 2 /BiOI nano powder.
  9. 9. The method for preparing a quaternary nano heterojunction photocatalyst as claimed in claim 5, wherein said S4 specifically comprises: S401, placing NaYF 4 :Yb,Tm@I-Fe-TiO 2 /BiOI nano powder into a mixed solvent of ethylene glycol and absolute ethyl alcohol, performing ultrasonic dispersion, dripping ammonia water, adjusting the pH of a system to 8.2, stirring, then performing constant-temperature reaction for 8 hours at 160 ℃, collecting a precipitate, washing and drying to obtain the NaYF 4 :Yb,Tm@I-Fe-TiO 2 /BiOI/Bi quaternary nano heterojunction photocatalyst.
  10. 10. Use of the quaternary nano heterojunction photocatalyst of any one of claims 1-4 in the treatment of industrial wastewater.

Description

Quaternary nano heterojunction photocatalyst and preparation method and application thereof Technical Field The invention relates to the technical field of environmental photocatalysis, in particular to a quaternary nano heterojunction photocatalyst and a preparation method and application thereof. Background Along with the development of society, organic pollution of water is continuously aggravated, the harm of refractory pollutants such as bisphenol A, orange II and the like is particularly remarkable, bisphenol A in global surface water is commonly detected (ng/L-mug/L level), reproduction disorder and gene damage can be caused by long-term exposure, orange II accounts for more than 60% of printing and dyeing wastewater pollutants, aromatic amine degradation products have strong carcinogenicity, and traditional treatment technologies such as low biodegradation efficiency, high advanced oxidation cost (5-15 yuan/ton of water), adsorption and transfer of pollution only are difficult to thoroughly mineralize pollutants. The photocatalytic oxidation technology is a key green path for treating the pollution by virtue of solar energy driving, no secondary pollution and high-efficiency mineralization capability. The existing photocatalysis system has full spectrum (ultraviolet-visible-near infrared) response capability, can regulate and control TiO 2 energy bands through I-Fe doping, and can promote carrier separation through BiOI/Bi heterojunction, and a multicomponent composite photocatalyst for expanding near infrared utilization through NaYF 4: yb and Tm up-conversion is not reported, and meanwhile, a high-efficiency synergistic degradation system for pollutants with different structural characteristics such as bisphenol A and orange II is also lacking in system research. Therefore, the NaYF 4:Yb,Tm@I-Fe-TiO2/BiOI/Bi nano heterojunction photocatalyst with full spectral response, high carrier separation efficiency and strong interface stability is developed, and has important significance for promoting the application of the photocatalysis technology in actual printing and dyeing and plastic wastewater treatment. In view of this, the present invention has been proposed. Disclosure of Invention The invention provides a natural light-driven full-spectrum-response NaYF 4:Yb,Tm@I-Fe-TiO2/BiOI/Bi nano heterojunction photocatalyst, preparation and application thereof, which can realize full-spectrum energy conversion under natural light and efficiently degrade pollutants such as bisphenol A, orange II and the like in wastewater, and aims to solve the problems of narrow spectral response, high carrier recombination rate, low degradation efficiency of difficult-to-degrade pollutants and the like of the existing photocatalytic material. The nano heterojunction photocatalyst with the up-conversion and multi-stage heterojunction synergistic characteristics is prepared by combining a solvothermal method, an in-situ deposition method and a sol-gel method, and has the characteristics of strong full-spectrum response, high carrier separation efficiency, good stability and the like. The synergistic enhancement is realized by integrating near infrared up-conversion of NaYF 4 to Yb and Tm, energy band regulation and control of I-Fe on TiO 2 and carrier separation function of BiOI/Bi, and finally the industrial wastewater containing nondegradable pollutants is efficiently treated under natural light. In order to achieve the purpose of the invention, the following technical scheme is adopted: The invention provides a quaternary nano heterojunction photocatalyst which is provided with a quaternary multi-stage core-shell structure, wherein the core of the core-shell structure takes NaYF 4 as a framework material and is doped with Yb 3+ and Tm 3+; The I and Fe co-doped TiO 2 semiconductor particles form a continuous and uniform shell layer outside the core; And a composite active layer formed by BiOI and simple substance Bi grows on the surface of the shell layer. Further, the molar ratio between the core and the shell is 1 (4-6); the molar ratio of the shell layer to the composite active layer is 1 (2-4). Further, the molar ratio between the core and the shell is 1:5; the molar ratio of the shell layer to the composite active layer is 1:3. Further, in the shell layer, the molar ratio of the three elements of I, fe and Ti is 0.1:0.001:1. Further, in the core, the molar ratio of the three elements of Y, yb and Tm is 79.5:20:0.5. The invention also provides a preparation method of the quaternary nano heterojunction photocatalyst, which comprises the following steps: S1, synthesizing a core by a hydrothermal method to obtain NaYF 4 Yb and Tm powder; s2, preparing NaYF 4:Yb,Tm@I-Fe-TiO2 powder by a sol method; S3, preparing NaYF 4:Yb,Tm@I-Fe-TiO2/BiOI nano powder by a chemical precipitation method; S4, preparing the NaYF 4:Yb,Tm@I-Fe-TiO2/BiOI/Bi quaternary nano heterojunction photocatalyst by a hydrothermal reduction method. Further