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CN-121976213-A - Preparation method of self-doped titanium dioxide nanotube electrode material

CN121976213ACN 121976213 ACN121976213 ACN 121976213ACN-121976213-A

Abstract

The invention relates to the technical field of photoelectric catalytic materials, and discloses a preparation method of a self-doped titanium dioxide nanotube electrode material. The method comprises the steps of (1) forming a titanium dioxide nanotube array on a titanium mesh surface by adopting an anodic oxidation method to obtain a material I, (2) carrying out preheating treatment on the material I to obtain a material II, (3) carrying out electrochemical reduction reaction on the material II serving as an anode in the presence of an ammonium sulfate solution to obtain a product I, and (4) carrying out annealing treatment on the product I at 400-500 ℃ to obtain the self-doped titanium dioxide nanotube electrode material. The self-doped titanium dioxide nanotube electrode material prepared by the method can expand the photoresponse range, increase the carrier density and charge transfer, and improve the conductivity.

Inventors

  • HOU JUNWEI
  • ZHANG HANYUE
  • YANG HAIYI
  • LIU XUAN
  • MA JINGUI

Assignees

  • 中国石油大学(北京)

Dates

Publication Date
20260505
Application Date
20251225

Claims (10)

  1. 1. The preparation method of the self-doped titanium dioxide nanotube electrode material is characterized by comprising the following steps: (1) Forming a titanium dioxide nanotube array on a titanium mesh surface by adopting an anodic oxidation method to obtain a material I; (2) Preheating the material I to obtain a material II; (3) In the presence of an ammonium sulfate solution, taking the material II as an anode to carry out electrochemical reduction reaction to obtain a product I; (4) Annealing the product I at 400-500 ℃ to obtain the self-doped titanium dioxide nanotube electrode material; wherein the average pipe diameter of the nano-pipes in the titanium dioxide nano-pipe array is 82-86nm, the average pipe length is 10-15 mu m, and the average pipe wall thickness is 10-18nm.
  2. 2. The method according to claim 1, wherein in the step (2), the conditions of the preheating treatment include a temperature of 280 to 400 ℃ for a time of 0.5 to 2 hours.
  3. 3. The method according to claim 1 or 2, wherein in step (3), the concentration of the ammonium sulfate solution is 0.2 to 0.6mol/L; and/or the conditions of the electrochemical reduction reaction comprise a voltage in the range of-1.3V to-1.6V for 8-12min.
  4. 4. A method according to claim 1 or 2, wherein in step (4) the annealing treatment is for a period of 1-3 hours.
  5. 5. The method according to claim 1 or 2, wherein in the step (1), the step of forming the titanium dioxide nanotube array on the titanium mesh surface by an anodic oxidation method comprises: And in the presence of electrolyte, carrying out electrochemical treatment by taking the pretreated titanium mesh as an anode and taking a platinum sheet as a cathode to obtain the material I.
  6. 6. The method according to claim 5, wherein the electrolyte contains ethylene glycol, water and ammonium fluoride; the content volume ratio of the glycol to the water is 30-35:1; The content of the ammonium fluoride is 17.5-19.5g relative to 100mL of water; The electrochemical treatment conditions comprise a voltage of 50-70V and a time of 1-3h.
  7. 7. A self-doped titania nanotube electrode material produced by the method of any one of claims 1-6.
  8. 8. The use of the self-doped titania nanotube electrode material of claim 7 for catalytic degradation of organic pollutants.
  9. 9. A method for degrading organic pollutants is characterized by comprising the steps of taking the self-doped titanium dioxide nanotube electrode material as an anode, taking a titanium sheet as a cathode, and carrying out photoelectric degradation on a mixed solution containing electrolyte and organic pollutants under the action of illumination conditions and external current.
  10. 10. The method of claim 9, wherein the organic contaminant is tetracycline; And/or, in the mixed solution, the concentration of the organic pollutant is 5-40mg/L; and/or, the current is 0.02-0.15A; and/or the catalytic degradation rate of the self-doped titanium dioxide nanotube electrode material to the organic pollutants is more than or equal to 85%.

Description

Preparation method of self-doped titanium dioxide nanotube electrode material Technical Field The invention relates to the technical field of photoelectric catalytic materials, in particular to a preparation method of a self-doped titanium dioxide nanotube electrode material. Background The titanium dioxide serving as a semiconductor photocatalyst has the advantages of no toxicity, good chemical stability, strong photosensitivity, low cost and the like, can basically convert organic matters into small molecules such as water, carbon dioxide and the like, and has wide research prospect. However, the wide band gap (3.2 eV) causes that the utilization rate of TiO 2 to sunlight is low, the recombination rate of photo-generated electrons and holes is high, titanium dioxide is a semiconductor, the conductivity is poor, and the electron transfer is difficult, and the three points severely limit the application of the titanium dioxide in the field of photoelectrocatalysis. The reduction of titania to provide oxygen vacancies solves the above problems, and most of the current reduction methods are to reduce titania using magnesium powder, acetylene, hydrogen, or the like. However, the reaction conditions of the above method are difficult to control and are accompanied by dangers. Disclosure of Invention The invention aims to solve the problems of small photoresponse range and large charge transfer resistance in the prior art. In order to achieve the above object, a first aspect of the present invention provides a method for preparing a self-doped titania nanotube electrode material, the method comprising: (1) Forming a titanium dioxide nanotube array on a titanium mesh surface by adopting an anodic oxidation method to obtain a material I; (2) Preheating the material I to obtain a material II; (3) In the presence of an ammonium sulfate solution, taking the material II as an anode to carry out electrochemical reduction reaction to obtain a product I; (4) Annealing the product I at 400-500 ℃ to obtain the self-doped titanium dioxide nanotube electrode material; wherein the average pipe diameter of the nano-pipes in the titanium dioxide nano-pipe array is 82-86nm, the average pipe length is 10-15 mu m, and the average pipe wall thickness is 10-18nm. A second aspect of the present invention provides a self-doped titania nanotube electrode material prepared by the method of the first aspect. A third aspect of the present invention provides the use of the self-doped titania nanotube electrode material of the second aspect for catalytic degradation of organic contaminants. According to a fourth aspect of the invention, there is provided a method for degrading organic contaminants, comprising photoelectrically degrading a mixed solution containing an electrolyte and organic contaminants under light conditions and applied current by using the self-doped titanium dioxide nanotube electrode material of the second aspect as an anode and a titanium sheet as a cathode. The self-doped titanium dioxide nanotube electrode material prepared by the method provided by the invention can expand the photoresponse range, increase the carrier density and charge transfer, improve the conductivity, improve the photoelectrocatalysis performance of the titanium dioxide nanotube electrode material, and further improve the catalytic degradation rate of organic pollutants. The invention uses electrochemical reduction, has mild reaction conditions and easy control, can not damage the binary titanium nanotube array structure, and ensures the catalytic activity. Drawings FIG. 1 is a schematic diagram of the process flow for preparing self-doped titania nanotube electrode material according to the present invention. FIG. 2 is a Raman spectrum of the titania nanotube electrode material prepared in example 1, comparative example 3 and comparative example 4 of the present invention. FIG. 3 is an ultraviolet-visible absorption spectrum of the titanium dioxide nanotube electrode material prepared in example 1 and comparative example 3 of the present invention. Fig. 4 is a graph showing band gap Tauc of the titania nanotube electrode material prepared in example 1 and comparative example 3 of the present invention. Fig. 5 is an SEM image of the titania nanotube electrode material prepared in example 1 and comparative example 3 of the present invention. FIG. 6 is an EPR spectrum of the self-doping titanium dioxide nanotube electrode material prepared in example 1 of the present invention. FIG. 7 is a graph showing the photo-degradation of the self-doped titania nanotube electrode material prepared in example 1 of the present invention at different initial tetracycline concentrations. FIG. 8 is a graph showing the photo-degradation of the self-doped titania nanotube electrode material prepared in example 1 of the present invention at different pH values. FIG. 9 is a graph showing the photodegradation of the self-doped titania nanotube electrode material prepar