Summary of the invention
In order to solve the shortcoming and defect part of prior art, primary and foremost purpose of the present invention is to provide a kind of to modify TiO
2nano-tube array is the preparation method of the ti-lead dioxide anode in middle layer.
Another object of the present invention is to provide a kind of by above-mentioned preparation method prepare to modify TiO
2nano-tube array is the ti-lead dioxide anode in middle layer.
Another object of the present invention is to provide above-mentioned to modify TiO
2nano-tube array is the application of the ti-lead dioxide anode in middle layer.
The object of the invention is achieved through the following technical solutions:
A kind of to modify TiO
2nano-tube array is the preparation method of the ti-lead dioxide anode in middle layer, comprises the following steps:
(1) Ti plate pre-treatment: titanium plate is polished, cleans, with stand-by after acid etch;
(2) be respectively negative electrode and anode with two blocks of titanium plates through step (1) pre-treatment, be placed on and prepare TiO containing carrying out anodic oxidation in hydrogen fluoride and second aqueous acid
2nano-tube array, then the titanium plate after anodic oxidation being placed on temperature is calcine 4 ~ 5h in the retort furnace of 450 ~ 600 DEG C, and cooling, obtains Ti/TiO
2nanometer pipe array electrode (Ti/TiO
2-NTs electrode);
(3) by Ti/TiO prepared by step (2)
2nanometer pipe array electrode is placed in 0.05 ~ 0.1mol/L AgNO
3in solution, ultrasonic 20 ~ 30min takes out, and then puts it into Na
2sO
4adopt electrodip process that Ag is deposited to Ti/TiO in electrolyte solution
2on nanotube, repeat the above-mentioned ultrasonic process to galvanic deposit 6 ~ 8 times, obtain Ti/TiO
2-NTs/Ag electrode;
(4) with the Ti/TiO of preparation in step (3)
2-NTs/Ag electrode is anode, and two blocks of titanium plates through step (1) pre-treatment of the same area are placed in anode both sides respectively as negative electrode, carry out anodic oxidation treatment, obtain Ti/TiO in containing the electrolyte solution of NaOH
2-NTs/Ag
2o electrode;
(5) with Ti/TiO prepared by step (4)
2-NTs/Ag
2o electrode is anode, and two blocks of titanium plates through step (1) pre-treatment with homalographic are placed in anode both sides respectively as negative electrode, negative and positive two interpole gap 1 ~ 1.5cm, containing Pb (NO
3)
2, HNO
3carry out electrochemical deposition with in the electrolyte solution of NaF He under 75 ~ 85 DEG C of temperature condition, obtain a kind of to modify TiO
2nano-tube array is the ti-lead dioxide anode (Ti/TiO in middle layer
2-NTs/Ag
2o/PbO
2).
Polishing described in step (1) refers to and polishes with 180 orders, 360 orders and 500 object sand paper successively; Described cleaning refers to and cleans with deionized water, acetone, methyl alcohol and ultrapure water successively; Described referring to by acid etch adopts volume ratio HF:HNO
3: H
2o is that the nitration mixture of 1:4:5 etches.
Described in step (2) is volume ratio HF containing hydrogen fluoride and second aqueous acid: acetic acid: H
2o is the solution of 0.04:1:8; Described anodic oxidation condition is: cathode and anode spacing 1 ~ 1.5cm, electrochemical oxidation 1h under employing D.C. regulated power supply 20 ~ 60V; Described cooling refers to that with speed of cooling be 1 ~ 2 DEG C/min cool to room temperature.
Galvanic deposit concrete operations described in step (3) are: with Ti/TiO
2nanotube is negative electrode, and two blocks of titanium plates through step (1) pre-treatment of the same area are placed in negative electrode both sides respectively as anode, cathode and anode spacing 1 ~ 1.5cm, adopts D.C. regulated power supply under 8 ~ 15V, Na
2sO
4concentration of electrolyte solutions is 0.1mol/L, and water bath with thermostatic control 85 DEG C, at Ti/TiO
2electrochemical deposition Ag 15 ~ 20min on nanotube.
Anodised condition described in step (4) is: adopt D.C. regulated power supply under 8 ~ 20V, the concentration of electrolyte solutions of cathode and anode spacing 1 ~ 1.5cm, NaOH is 1mol/L and room temperature condition anodic oxygenization 2 ~ 3min.
Electrochemical deposition process described in step (5) is: be 0.12A/cm in current density
2condition under deposit 20min, be then 0.06A/cm in current density
2condition under deposit 100min; Described containing Pb (NO
3)
2, HNO
3with the electrolyte solution of NaF for containing 200g/L Pb (NO
3)
2, 0.1mol/L HNO
3with the solution of 0.05mol/L NaF.
A kind of to modify TiO
2nano-tube array is the ti-lead dioxide anode in middle layer, is prepared by above preparation method.
Above-mentioned to modify TiO
2nano-tube array is the application of ti-lead dioxide anode in process organic wastewater with difficult degradation thereby in middle layer.
Had the following advantages and beneficial effect by preparation method of the present invention and the product tool that obtains:
(1) electrode of the present invention is by PbO
2deposit in titania nanotube three-dimensional structure, added PbO
2the combination degree of coating and Ti plate, makes accelerated service electrode life from Ti/PbO
28.89h extend to Ti/TiO
2-NTs/Ag
2o/PbO
2the 47.22h of electrode;
(2) Ag
2o is TiO 2 nanotubes modified is the Ti/TiO in middle layer
2-NTs/Ag
2o/PbO
2electrode improves the oxygen evolution potential of electrode, and oxygen evolution potential is from Ti/PbO
21.9V bring up to Ti/TiO
2-NTs/Ag
2o/PbO
2the 2.6V of electrode;
(3) preparation method's technique of the present invention is simple, low for equipment requirements, and the electrode of preparation has stronger electrochemical oxidation ability, to the defluorinate rate of Perfluorocaprylic Acid (PFOA) from Ti/PbO
237.12% bring up to Ti/TiO
2-NTs/Ag
2o/PbO
287.53% of electrode.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the present invention is described in further detail, but embodiments of the present invention are not limited thereto.
Embodiment 1
The one of the present embodiment is to modify TiO
2nano-tube array is the preparation method of the ti-lead dioxide anode in middle layer, and concrete preparation process is as follows:
(1) rectangle Ti plate is got, be of a size of 30mm × 20mm, thick 0.8mm, 180 orders, 360 orders and 500 object sand paper are used to polish to smooth step by step, use deionized water, acetone, washed with methanol 15min respectively, clean 3 times with ultrapure water again, then Ti plate is placed in 50mL mixed acid solution (HF:HNO
3: H
2o, 1:4:5, V:V:V) etch 10min, the Ti plate after etching cleans up with ultrapure water again;
(2) anonizing is adopted to prepare TiO
2-NTs electrode: being that anode and cathode is placed in volume ratio HF: acetic acid: H through the titanium plate of step (1) pre-treatment
2o is in the solution of 0.04:1:8, cathode and anode spacing 1.0cm, constant voltage 40V, after reaction times 1h, clean with ultrapure water after taking out anode Ti plate, naturally dry stand-by, then at retort furnace constant temperature 500 DEG C of temperature lower calcination 4.5h, with rate of cooling be 1.5 DEG C/min be cooled to room temperature obtain stablize Ti/TiO
2nanometer pipe array electrode (Ti/TiO
2-NTs electrode);
(3) Ti/TiO
2prepared by-NTs/Ag electrode: preparation 0.08mol/L AgNO
3solution, by Ti/TiO
2nanometer pipe array electrode is immersed in wherein ultrasonic 25min, then with this Ti/TiO
2nanometer pipe array electrode is negative electrode, and the titanium plate through step (1) pre-treatment of same area, as anode, is placed on negative electrode both sides, cathode and anode spacing 1.0cm, respectively with 0.1mol/L Na
2sO
4for ionogen, constant voltage 10V, electrolyte temperature 85 DEG C, galvanic deposit 15min, powered-down, by Ti/TiO
2nanotube electrode puts into 0.08mol/LAgNO again
3ultrasonic 25min in solution, again as cathode electrodeposition 15min, natural air drying after the ultrasonic of 8 repetitions and deposition process, obtains Ti/TiO
2-NTs/Ag electrode.
(4) Ti/TiO
2-NTs/Ag
2prepared by O electrode: with Ti/TiO
2-NTs/Ag electrode is anode, and the titanium plate through step (1) pre-treatment of same area, as negative electrode, is placed on anode both sides respectively, cathode and anode spacing 1.5cm, at constant 15V voltage, 1mol/L NaOH alkaline solution is under electrolyte conditions, room temperature anodic oxidation 2min, Ti/TiO
2-NTs/Ag electrode is transformed into Ti/TiO
2-NTs/Ag
2o electrode;
(5) Ti/TiO
2-NTs/Ag
2o/PbO
2the preparation of electrode: preparation 70mL contains 200g/L Pb (NO
3)
2, 0.1mol/L HNO
3with the solution of 0.05mol/L NaF, with Ti/TiO in above-mentioned solution
2-NTs/Ag
2o electrode is anode, two blocks of titanium plates through step (1) pre-treatment with homalographic are placed on anode both sides as negative electrode, negative and positive two interpole gap is 1.5cm, adopt two electrolysis systems of DC current regulator power supply, temperature is 80 DEG C, electrodeposit reaction 2h, front 20min constant current density 0.12A/cm
2, rear 100min constant current density 0.06A/cm
2, prepare Ti/TiO
2-NTs/Ag
2o/PbO
2electrode.
The Ti/TiO that the present embodiment obtains
2nanometer pipe array electrode, Ti/TiO
2-NTs/Ag
2o electrode and Ti/TiO
2-NTs/Ag
2o/PbO
2the scanning electron microscope (SEM) photograph of electrode, respectively as shown in Figure 1, Figure 2 and Figure 3.As seen from Figure 1, Ti/TiO
2nanometer pipe array electrode defines complete nano-tube array structure; As seen from Figure 2, silver suboxide has deposited to Ti/TiO
2nanometer pipe array electrode surface; As seen from Figure 3, Ti/TiO
2-NTs/Ag
2o/PbO
2electrode surface presents the comparatively regular particle of shape, arranges compact.The Ti/TiO that the present embodiment obtains
2nanometer pipe array electrode, Ti/TiO
2-NTs/Ag
2o electrode and Ti/TiO
2-NTs/Ag
2o/PbO
2respectively as shown in Figure 4, Figure 5 and Figure 6, as can be seen from Fig. 4,2 θ angles, on 25.3 °, 48.1 °, 53.2 ° directions, belong to the characteristic peak that the tetragonal system of titania nanotube is anatase structured to the XRD figure spectrum of electrode; As can be seen from Fig. 5,2 θ angles, on 32.5 °, 38.1 °, 63.5 ° directions, belong to the characteristic peak of monoclinic silver suboxide; As can be seen from Fig. 6,2 θ angles, on 32.2 °, 49 °, 63.7 ° directions, belong to PbO
2the thing phase of tetragonal system β type.
Embodiment 2
The one of the present embodiment is with Ag
2o modifies TiO
2nano-tube array is the preparation method of the ti-lead dioxide anode in middle layer, and concrete preparation process is as follows:
(1) rectangle Ti plate is got, be of a size of 30mm × 20mm, thick 0.8mm, 180 orders, 360 orders and 500 object sand paper are used to polish to smooth step by step, use deionized water, acetone, washed with methanol 15min respectively, clean 3 times with ultrapure water again, then Ti plate is placed in 50mL mixed acid solution (HF:HNO
3: H
2o, 1:4:5, V:V:V) etch 10min, the Ti plate after etching cleans up with ultrapure water again;
(2) anonizing is adopted to prepare TiO
2-NTs electrode: being that anode and cathode is placed in volume ratio HF: acetic acid: H through the titanium plate of step (1) pre-treatment
2o is in the solution of 0.04:1:8, cathode and anode spacing 1.5cm, constant voltage 60V, after reaction times 1h, clean with ultrapure water after taking out anode Ti plate, naturally dry stand-by, then at retort furnace constant temperature 600 DEG C of temperature lower calcination 4h, with rate of cooling be 2 DEG C/min be cooled to room temperature obtain stablize Ti/TiO
2nanometer pipe array electrode (Ti/TiO
2-NTs electrode);
(3) Ti/TiO
2prepared by-NTs/Ag electrode: preparation 0.05mol/L AgNO
3solution, by Ti/TiO
2nanometer pipe array electrode is immersed in wherein ultrasonic 30min, then with this Ti/TiO
2nanometer pipe array electrode is negative electrode, and the titanium plate through step (1) pre-treatment of same area, as anode, is placed on negative electrode both sides, cathode and anode spacing 1.5cm, respectively with 0.1mol/L Na
2sO
4for ionogen, constant voltage 15V, electrolyte temperature 85 DEG C, galvanic deposit 15min, powered-down, by Ti/TiO
2nanotube electrode puts into 0.05mol/LAgNO again
3ultrasonic 30min in solution, again as cathode electrodeposition 15min, natural air drying after the ultrasonic of 6 repetitions and deposition process, obtains Ti/TiO
2-NTs/Ag electrode.
(4) Ti/TiO
2-NTs/Ag
2prepared by O electrode: with Ti/TiO
2-NTs/Ag electrode is anode, and the titanium plate through step (1) pre-treatment of same area, as negative electrode, is placed on anode both sides respectively, cathode and anode spacing 1.5cm, at constant 20V voltage, 1mol/L NaOH alkaline solution is under electrolyte conditions, room temperature anodic oxidation 3min, Ti/TiO
2-NTs/Ag electrode is transformed into Ti/TiO
2-NTs/Ag
2o electrode;
(5) Ti/TiO
2-NTs/Ag
2o/PbO
2the preparation of electrode: preparation 70mL contains 200g/L Pb (NO
3)
2, 0.1mol/L HNO
3with the solution of 0.05mol/L NaF, with Ti/TiO in above-mentioned solution
2-NTs/Ag
2o electrode is anode, two blocks of titanium plates through step (1) pre-treatment with homalographic are placed on anode both sides as negative electrode, negative and positive two interpole gap is 1.0cm, adopt two electrolysis systems of DC current regulator power supply, temperature is 85 DEG C, electrodeposit reaction 2h, front 20min constant current density 0.12A/cm
2, rear 100min constant current density 0.06A/cm
2, prepare Ti/TiO
2-NTs/Ag
2o/PbO
2electrode.
Embodiment 3
The one of the present embodiment is to modify TiO
2nano-tube array is the preparation method of the ti-lead dioxide anode in middle layer, and concrete preparation process is as follows:
(1) rectangle Ti plate is got, be of a size of 30mm × 20mm, thick 0.8mm, 180 orders, 360 orders and 500 object sand paper are used to polish to smooth step by step, use deionized water, acetone, washed with methanol 15min respectively, clean 3 times with ultrapure water again, then Ti plate is placed in 50mL mixed acid solution (HF:HNO
3: H
2o, 1:4:5, V:V:V) etch 10min, the Ti plate after etching cleans up with ultrapure water again;
(2) anonizing is adopted to prepare TiO
2-NTs electrode: being that anode and cathode is placed in volume ratio HF: acetic acid: H through the titanium plate of step (1) pre-treatment
2o is in the solution of 0.04:1:8, cathode and anode spacing 1cm, constant voltage 20V, after reaction times 1h, clean with ultrapure water after taking out anode Ti plate, naturally dry stand-by, then at retort furnace constant temperature 450 DEG C of temperature lower calcination 5h, with rate of cooling be 1 DEG C/min be cooled to room temperature obtain stablize Ti/TiO
2nanometer pipe array electrode (Ti/TiO
2-NTs electrode);
(3) Ti/TiO
2prepared by-NTs/Ag electrode: preparation 0.1mol/LAgNO
3solution, by Ti/TiO
2nanometer pipe array electrode is immersed in wherein ultrasonic 20min, then with this Ti/TiO
2nanometer pipe array electrode is negative electrode, and the titanium plate through step (1) pre-treatment of same area, as anode, is placed on negative electrode both sides, cathode and anode spacing 1cm, respectively with 0.1mol/L Na
2sO
4for ionogen, constant voltage 8V, electrolyte temperature 85 DEG C, galvanic deposit 20min, powered-down, by Ti/TiO
2nanotube electrode puts into 0.1mol/L AgNO again
3ultrasonic 20min in solution, again as cathode electrodeposition 20min, natural air drying after the ultrasonic of 7 repetitions and deposition process, obtains Ti/TiO
2-NTs/Ag electrode.
(4) Ti/TiO
2-NTs/Ag
2prepared by O electrode: with Ti/TiO
2-NTs/Ag electrode is anode, and the titanium plate through step (1) pre-treatment of same area, as negative electrode, is placed on anode both sides respectively, cathode and anode spacing 1cm, at constant 8V voltage, 1mol/L NaOH alkaline solution is under electrolyte conditions, room temperature anodic oxidation 2min, Ti/TiO
2-NTs/Ag electrode is transformed into Ti/TiO
2-NTs/Ag
2o electrode;
(5) Ti/TiO
2-NTs/Ag
2o/PbO
2the preparation of electrode: preparation 70mL contains 200g/LPb (NO
3)
2, 0.1mol/L HNO
3with the solution of 0.05mol/L NaF, with Ti/TiO in above-mentioned solution
2-NTs/Ag
2o electrode is anode, two blocks of titanium plates through step (1) pre-treatment with homalographic are placed on anode both sides as negative electrode, negative and positive two interpole gap is 1.0cm, adopt two electrolysis systems of DC current regulator power supply, temperature is 75 DEG C, electrodeposit reaction 2h, front 20min constant current density 0.12A/cm
2, rear 100min constant current density 0.06A/cm
2, prepare Ti/TiO
2-NTs/Ag
2o/PbO
2electrode.
Comparative example 1
Traditional method prepares Ti/PbO
2electrode adopts electrochemical deposition method: get rectangle Ti plate, be of a size of 30mm × 20mm, thick 0.8mm, 180 orders, 360 orders and 500 object sand paper are used to polish to smooth step by step, and then use deionized water, acetone, washed with methanol 15min respectively, clean 3 times with ultrapure water again, then Ti plate is placed in 50mL mixed acid solution (HF:HNO
3: H
2o, 1:4:5, V:V:V) etch 10min, Ti plate after etching cleans up with ultrapure water again, makes anode stand-by, same area do negative electrode through pretreated two blocks of titanium plates, be placed on anode both sides respectively, cathode and anode spacing 1cm, be then placed in preparation 70mL and contain 200g/LPb (NO
3)
2, 0.1mol/L HNO
3with in the solution of 0.05mol/L NaF, controlling bath temperature is 75 DEG C, and stirring velocity is 300r/min, electrodeposit reaction 2h, front 20min constant current density 0.12A/cm
2, rear 100min constant current density 0.06A/cm
2, reaction terminates rear acquisition Ti/PbO
2electrode.
Comparative example 2
Ti/TiO
2-NTs/PbO
2the preparation of electrode: adopt 180 orders, 360 orders and 500 order sand papering Ti plates (30mm × 20mm × 0.8mm) to smooth, more respectively with deionized water, acetone, methyl alcohol, ultrapure water cleaning 15min, mixed acid solution (HF:HNO
3: H
2o, 1:4:5, V:V:V) etch titanium plate after ultrapure water cleaning stand-by, TiO is prepared in anodic oxidation
2the electrolytic solution of nano-tube array is HF, acetic acid and H
2o solution (0.04:1:8, V:V:V), under the operational condition of cathode and anode spacing 1cm, constant voltage 40V, with ultrapure water after electrochemical oxidation Ti plate 1h, naturally dry, adopt retort furnace to calcine at constant temperature 500 DEG C through anodised Ti plate 4.5h, rate of cooling 1.5 DEG C/min is set and is cooled to room temperature, obtain and stablize Ti/TiO
2nanometer pipe array electrode (Ti/TiO
2-NTs electrode);
Electrochemical deposition method is adopted to prepare PbO
2coating: by Ti/TiO
2-NTs electrode is as anode, and two blocks of Ti plates with homalographic are placed on anode both sides respectively as negative electrode, cathode and anode spacing 1.5cm, and electrodeposit liquid is 200g/L Pb (NO
3)
2, 0.1mol/L HNO
3with the mixing solutions of 0.05mol/L NaF, two electrode systems are adopted to be 80 DEG C, front 20min constant current density 0.12A/cm in temperature
2, rear 100min constant current density 0.06A/cm
2operational condition under prepare Ti/TiO
2-NTs/PbO
2electrode.
The Ti/PbO that comparative example 1 obtains
2the Ti/TiO that electrode, comparative example 2 obtain
2-NTs/PbO
2the Ti/TiO that electrode and embodiment 1 obtain
2-NTs/Ag
2o/PbO
2the linear sweep voltammetry collection of illustrative plates of electrode as shown in Figure 7.As can be seen from Figure 7 Ti/PbO
2electrode, Ti/TiO
2-NTs/PbO
2electrode and Ti/TiO
2-NTs/Ag
2o/PbO
2the oxygen evolution potential of electrode is in the trend raised gradually.Oxygen evolution potential test condition: experiment takes electrochemical workstation three-electrode system, Ti/PbO
2electrode, Ti/TiO
2-NTs/PbO
2electrode and Ti/TiO
2-NTs/Ag
2o/PbO
2electrode is respectively working electrode, and the titanium plate through pre-treatment of same size is as to electrode, and working electrode and to interelectrode distance 1.5cm, saturated calomel electrode (SCE) is as reference electrode, and electrolyte solution is 0.5mol/L H
2sO
4solution.At initial potential 0V, stop current potential 5.0V, scanning speed 0.1V, sampling interval 0.001V, rest time 2s, sensitivity 1 × e
-0.001analyzing electrode oxygen evolution potential under A/V condition.
The Ti/PbO that comparative example 1 obtains
2the Ti/TiO that electrode, comparative example 2 obtain
2-NTs/PbO
2the Ti/TiO that electrode and embodiment 1 obtain
2-NTs/Ag
2o/PbO
2the life test result of electrode is as shown in table 1.Ti/PbO as can be seen from Table 1
2the accelerated service life-span of electrode is 8.89h, Ti/TiO
2-NTs/PbO
2the accelerated service life-span of electrode is 43.61h, Ti/TiO
2-NTs/Ag
2o/PbO
2the electrode accelerated service life-span is 47.22h.Accelerated service life test experiment condition: adopt electrochemical analyser CHI6081D three-electrode system galvanostatic method, Ti/PbO
2electrode, Ti/TiO
2-NTs/PbO
2electrode and Ti/TiO
2-NTs/Ag
2o/PbO
2electrode is respectively working electrode, and platinum plate (2.0cm × 3.0cm) is as to electrode, and working electrode and to interelectrode distance 1.5cm, saturated calomel electrode (SCE) is as reference electrode, and electrolyte solution is 0.5mol/L H
2sO
4solution.Constant current density 83.33mA/cm is set
2scan, have time during obscission to be considered to accelerated service electrode life when voltage raises 5V or layer electrodes.
Table 1 accelerated service electrode life
The Ti/PbO that comparative example 1 obtains
2the Ti/TiO that electrode, comparative example 2 obtain
2-NTs/PbO
2the Ti/TiO that electrode and embodiment 1 obtain
2-NTs/Ag
2o/PbO
2the defluorinate rate curve figure of electrode electro Chemical oxidation Perfluorocaprylic Acid (PFOA) as shown in Figure 8.As can be seen from Figure 8, Ti/PbO
2the defluorinate rate of electrode pair PFOA is 37.12%, Ti/TiO
2-NTs/PbO
2the defluorinate rate of electrode pair PFOA is 61.69%, Ti/TiO
2-NTs/Ag
2o/PbO
2the defluorinate rate of electrode pair PFOA is 87.53%.The experiment condition of electrode electro Chemical oxidation PFOA: measure the 80mL 100mg/L PFOA aqueous solution and put into synthetic glass reactor, add 0.112g NaClO in the PFOA aqueous solution
4ionogen, makes NaClO
4concentration reaches 1.4g/L.Respectively with Ti/PbO
2electrode, Ti/TiO
2-NTs/PbO
2electrode and Ti/TiO
2-NTs/Ag
2o/PbO
2electrode as anode, same size through the Titanium board of pre-treatment as negative electrode, cathode-anode plate spacing 1cm.Adopt two electrode system continuous current 30mA/cm
2, magnetic agitation speed 1200r/min, electrochemical oxidation PFOA180min at bath temperature 31 DEG C.
Above-described embodiment is the present invention's preferably embodiment; but embodiments of the present invention are not restricted to the described embodiments; change, the modification done under other any does not deviate from spirit of the present invention and principle, substitute, combine, simplify; all should be the substitute mode of equivalence, be included within protection scope of the present invention.