CN101721987A - Fluorine and boron codope titanium dioxide nanotube thin film photoelectrode and preparation method thereof - Google Patents

Abstract

The invention discloses a fluorine and boron codope titanium dioxide nanotube thin film photoelectrode, which comprises a titanium sheet base and a fluorine and boron codope titanium dioxide nanotube thin film layer which grows in situ on the titanium sheet base. In a preparation method, the anode oxidation method is employed to grow the titanium dioxide nanotube on the titanium sheet base; then the method of chemical gaseous phase deposition is employed to codope the fluorine and boron into the titanium dioxide nanotube layers. Compared with normal titanium dioxide film, the fluorine and boron codope titanium dioxide nanotube thin film photoelectrode features larger specific surface area and better adsorptive capacity, thus greatly enhancing photocatalysis capacity and photoelectric conversion efficiency of titanium dioxide thin film photoelectrode. Fluorine and boron codope creates a synergistic effect, which can obviously improve visible light catalytic activity of TiO2. The fluorine and boron codope titanium dioxide nanotube thin film photoelectrode of the invention can be applied to solar energy utilization, photoelectric conversion and degradation of organic pollutants in the field of environment.

Description

Fluorine, boron codope titanium dioxide nanotube thin film photoelectrode and preparation method thereof

Technical field

The present invention relates to fluorine, boron codope titanium dioxide nanotube thin film photoelectrode and preparation method thereof, belong to the semiconductor photoelectrocatalysielectrode technical field.

Background technology

In recent years, the light-catalysed research of semiconductor nano material has obtained paying close attention to widely.Especially in environmental pollution control field, because nano titanium oxide has significant photocatalytic Degradation to many environmental contaminants, photocatalysis has developed into novel environmental pollution treatment technology.And as the core of photocatalysis technology, advantage such as titanium dioxide has the catalytic activity height, stable in properties is corrosion-resistant and nontoxic; But in application, also exist some problems, such as its can only absorbing wavelength less than the light of 387 nanometers, can't utilize the visible light part that accounts for the main energy of sunshine; Electricity conversion is not high; And the immobilization problem in the catalyst use.How in the immobilized while of catalyst, improve its photocatalytic activity as much as possible, and its photoresponse is extended to visible-range in the hope of utilizing solar energy more fully, be the important research content in photoelectrocatalysis field always.

Studies show that titania nanotube has higher specific activity surface area, thereby has higher photocatalytic activity; And F, B codope have produced certain synergy, can significantly improve TiO ₂Visible light catalysis activity.

Summary of the invention

The objective of the invention is to propose a kind of high visible response of having, the fluorine of stable in properties, boron codope titanium dioxide nanotube thin film photoelectrode and preparation method thereof.

Boron doped titanic oxide nano tube thin-film photoelectric electrode of the present invention comprises that substrate of titanium sheet and growth in situ are at the suprabasil fluorine of titanium sheet, boron codope titanium dioxide nanotube thin film layer.

The preparation method of fluorine, boron codope titanium dioxide nanotube thin film photoelectrode may further comprise the steps:

1) with the grinding and polishing of pure titanium sheet to surperficial no marking, with acetone and deionized water ultrasonic cleaning, drying;

2) with NH ₄F, oxalic acid and water are mixed with electrolyte with mass ratio at 1: 2: 200, and regulating the pH value is 2.7～4.9, are anode with the titanium sheet of step 1), the nickel plate is made negative electrode, under 15V～25V constant voltage dc source, stir oxidation 30～120 minutes, obtain unformed titania nanotube;

3) unformed titania nanotube is put into the settling chamber of chemical vapor deposition unit, with the NaF solution of 25g/L and the H of 25g/L ₃BO ₃Solution is presoma, and nitrogen is carrier gas, flow velocity 0.002m/s～0.02m/s; at 400 ℃ of deposit 100-150 minutes, deposition finished the back and continues logical nitrogen to remove predecessor residual in the settling chamber, then under nitrogen protection; in 400 ℃ of calcinings 60-180 minute, cooling naturally.

Among the preparation method of the present invention, can control the caliber of nanotube by the pH value that changes anodised voltage and electrolyte; Can control the pipe range of nanotube by changing oxidization time; The nitrogen flow rate, the sedimentation time that change in the chemical vapour deposition (CVD) can obtain different fluorine, boron doping concentration.

Advantage of the present invention:

1, adopt anodizing to prepare titanic oxide nano tube thin-film, technology is simple, and cost is low, is easy to control;

2, the structure of nanotube has higher specific activity surface area, can effectively improve electricity conversion;

3, adopt the nonmetal fluorine of chemical gaseous phase depositing process codope, boron, doping content is easy to control;

4, that boron is mixed is more even for chemical gaseous phase depositing process, and codope the sample of nonmetal fluorine, boron have very high visible light activity.

5, fluorine of the present invention, boron codope titanium dioxide nanotube thin film photoelectrode can be used for the solar energy utilization, photoelectricity transforms and the degraded of the organic pollution of environmental area.

Description of drawings

Fig. 1 is a structural profile schematic diagram of the present invention;

Fig. 2 is the surface scan electromicroscopic photograph of fluorine, boron codope titanium dioxide nanotube thin film photoelectrode.

The specific embodiment

Further specify the present invention below by accompanying drawing and example.

With reference to Fig. 1, fluorine, boron codope titanium dioxide nanotube thin film photoelectrode comprise that substrate 2 of titanium sheet and growth in situ are at the suprabasil boron doped titanic oxide nano tube thin-film layer 1 of titanium sheet.

Example:

Get NH ₄F 2.5 grams, oxalic acid 5 grams are dissolved in 500 ml waters, and the pH value transfers to 3.7, obtains electrolyte; As anode, negative electrode is the nickel plate, carries out anodic oxidation 120 minutes under 20V voltage, obtains unbodied titania nanotube structure with the titanium sheet handled; Adopt chemical gaseous phase depositing process that it is carried out fluorine, boron then and mix, wherein precursor liquid is the NaF solution of 25g/L of 50 ℃ of temperature and the H of 25g/L ₃BO ₃Solution; Nitrogen is carrier gas, flow velocity 0.015m/s; 400 ℃ of deposit 2 hours; Deposition finishes the back and continues logical nitrogen to remove predecessor residual in the settling chamber; then under nitrogen protection; calcined 1 hour for 400 ℃; naturally cooling; obtain fluorine, boron codope titanium dioxide nanotube thin film photoelectrode; its surface scan electromicroscopic photograph as shown in Figure 2, as seen from the figure, the titanic oxide nano tube thin-film photoelectric electrode that makes has tangible tubular structure.

The optoelectronic pole that this example is made carries out photoelectric current measurement and the experiment of photoelectric catalysis degrading methyl orange, and (preparation gained membrane electrode is the anode working electrode to photoelectric measurement, and the nickel plate is to electrode, and saturated calomel electrode is a reference electrode, the Na of 0.5M in three-electrode system ₂SO ₄Be supporting electrolyte) carry out.Light source is selected the visible light of wavelength greater than 460 nanometers.Add anodic bias 0V～1.6V, the variation of recording light electric current.The result shows that the optoelectronic pole of preparation has higher density of photocurrent, can effectively improve electricity conversion.

In three-electrode system, add the methyl orange illumination 120 minutes of 10ppm at above-mentioned photoelectric measurement, analyze the change in concentration of methyl orange.The result shows, fluorine of the present invention, boron codope titanium dioxide nanotube thin film electrode degrading methyl orange solution, and when initial concentration was 10mg/L, the degradation efficiency of MO was 90.4%.

Claims (2)

1. fluorine, boron codope titanium dioxide nanotube thin film photoelectrode is characterized in that comprising that titanium sheet substrate (2) and growth in situ are at the suprabasil boron doped titanic oxide nano tube thin-film layer of titanium sheet (1).

2. prepare the method for the described fluorine of claim 1, boron codope titanium dioxide nanotube thin film photoelectrode, it is characterized in that may further comprise the steps:

1) with the grinding and polishing of pure titanium sheet to surperficial no marking, with acetone and deionized water ultrasonic cleaning, drying;

2) NH4F, oxalic acid and water are mixed with electrolyte with mass ratio at 1: 2: 200, regulating the pH value is 2.7～4.9, is anode with the titanium sheet of step 1), the nickel plate is made negative electrode, under 15V～25V constant voltage dc source, stir oxidation 30～120 minutes, obtain unformed titania nanotube;

3) unformed titania nanotube is put into the settling chamber of chemical vapor deposition unit, with the NaF solution of 25g/L and the H of 25g/L ₃BO ₃Solution is presoma, and nitrogen is carrier gas, flow velocity 0.002m/s～0.02m/s; at 400 ℃ of deposit 100-150 minutes, deposition finished the back and continues logical nitrogen to remove predecessor residual in the settling chamber, then under nitrogen protection; in 400 ℃ of calcinings 60-180 minute, cooling naturally.

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