阅读说明：本技术 一种三元半导体复合薄膜及其制备方法及其应用 (Ternary semiconductor composite film and preparation method and application thereof ) 是由 郭惠霞 刘籽烨 李亮亮 苏策 于冬梅 张玉蓉 于 2019-08-02 设计创作，主要内容包括：本发明涉及光电化学阴极保护技术领域,具体为一种三元半导体复合薄膜及其制备方法和应用,其目的在于针对现有技术中指出的不足,提供一种三元半导体复合薄膜及其制备方法和应用,旨在解决现有技术中单一TiO2半导体材料宽带隙在吸收光之后产生的电子的迁移率较低,电子和空穴的分离效果较差,容易导致光生电荷发生复合和较短的光响应范围等问题；通过阳极氧化法、连续离子层吸附法和水热法等在钛片上依次制备了TiO2、TiO2/CdS、TiO2/CdS/ZnFe2O4薄膜；其有益效果在于：TiO2/CdS/ZnFe2O4薄膜的光电化学性质和光生阴极保护性能与单一TiO2样品相比都有显著地提升,对不锈钢具有优异的防腐保护性能。(The invention relates to the technical field of photoelectrochemistry cathodic protection, in particular to a ternary semiconductor composite film and a preparation method and application thereof, aiming at overcoming the defects pointed out in the prior art, providing the ternary semiconductor composite film and the preparation method and application thereof and aiming at solving the problems that in the prior art, the mobility of electrons generated after a single TiO2 semiconductor material wide band gap absorbs light is low, the separation effect of the electrons and holes is poor, the photogenerated charges are easy to be compounded, the photoresponse range is short and the like; sequentially preparing TiO2, TiO2/CdS and TiO2/CdS/ZnFe2O4 films on a titanium sheet by an anodic oxidation method, a continuous ion layer adsorption method, a hydrothermal method and the like; the beneficial effects are that: compared with a single TiO2 sample, the photoelectrochemical property and the photoproduction cathodic protection performance of the TiO2/CdS/ZnFe2O4 film are both obviously improved, and the film has excellent anticorrosion protection performance on stainless steel.)

1. A ternary semiconductor composite film is characterized by comprising the following components: TiO2, CdS and ZnFe2O 4.

2. A method for producing the ternary semiconductor composite film according to claim 1, comprising the steps of:

step (1): pretreating a titanium sheet, preparing a TiO2 nanotube by adopting an anodic oxidation method to obtain the titanium sheet covered with a TiO2 nanotube film, calcining and annealing the titanium sheet covered with the TiO2 nanotube film, and taking out a substrate sample for later use;

step (2): preparing CdS nano-particles by adopting a continuous ion layer adsorption method, circularly soaking the substrate sample obtained in the step (1) in Cd (NO3)2 solution, distilled water, Na2S solution and distilled water in sequence, soaking each solution for 1min, circularly soaking the four solutions in sequence for 15 times, drying, and taking out the substrate sample for later use;

and (3): and (3) putting the substrate sample obtained in the step (2) into a reaction kettle, preparing a ZnFe2O4 nanosheet by adopting a hydrothermal method, washing the product, and drying to obtain the ternary composite film.

3. The method for preparing a ternary semiconductor composite film according to claim 2, wherein: in the step (1), the TiO2 nanotube is prepared by using ammonium fluoride as a raw material and 97% ethylene glycol aqueous solution as a solvent.

4. The method for preparing a ternary semiconductor composite film according to claim 2, wherein: in the step (1), the reaction conditions of the anodic oxidation method are 20V voltage, and the reaction time is 1h respectively; the calcining temperature is 450 ℃, and the annealing time is 2 h.

5. The method for preparing a ternary semiconductor composite film according to claim 2, wherein: in the step (2), the CdS nanoparticles are prepared by adopting cadmium nitrate and sodium sulfide as raw materials and water as a solvent.

6. The method for preparing a ternary semiconductor composite film according to claim 2, wherein: in the step (3), the raw materials adopted for preparing the ZnFe2O4 nanosheets are ferric nitrate and zinc nitrate, and the solvent used is water.

7. The method for preparing a ternary semiconductor composite film according to claim 2, wherein: in the step (3), the reaction temperature of the hydrothermal method is 100 ℃, and the reaction time is 10 h; the drying temperature is 60 ℃, and the annealing time is 4 h.

8. Use of the ternary semiconductor composite film according to claim 1 as a photocathode protective material.

Technical Field

The invention relates to the technical field of photoelectrochemistry cathode protection, in particular to a ternary semiconductor composite film and a preparation method and application thereof.

Background

Stainless steel is widely used in various fields of modern society due to its excellent corrosion resistance, however, its properties are related to an exposed environment, and local corrosion may occur when immersed in a chlorine or moisture-containing environment. Therefore, there is a need to improve the corrosion resistance of stainless steel, and the existing corrosion resistance methods include coating a protective coating, adding a corrosion inhibitor, and performing an electrochemical protection method, wherein the electrochemical protection method has the advantages of long service life, wide protection range, and the like, but usually causes energy and material loss. There is therefore a need to optimize the electrochemical protection process. Since TiO2 coatings can be used for electrochemical photocathode protection of metals, TiO 2-based nanostructured materials have attracted considerable attention in the field of corrosion protection. Related research shows that electrons generated by the TiO2 photo-anode can be transferred to metal under irradiation, and form a more negative corrosion potential than stainless steel. However, TiO2 has two drawbacks, namely a wide band gap and rapid photogenerated electron-hole pair recombination, which greatly reduces the photo-induced charge conversion efficiency under visible light irradiation and the photocathode protective properties of TiO2 thin films.

Disclosure of Invention

The invention aims to provide a ternary semiconductor composite film and a preparation method and application thereof aiming at solving the problems that in the prior art, a single TiO2 semiconductor material wide band gap generates low electron mobility after absorbing light, the separation effect of electrons and holes is poor, photogenerated charges are easy to recombine, the photoresponse range is short, and the like.

In order to achieve the purpose, the invention adopts the following technical scheme:

a ternary semiconductor composite film is characterized by comprising the following components: TiO2, CdS and ZnFe2O 4.

A preparation method of a ternary semiconductor composite film is characterized by comprising the following steps:

step (1): pretreating a titanium sheet, preparing a TiO2 nanotube by adopting an anodic oxidation method to obtain the titanium sheet covered with a TiO2 nanotube film, calcining and annealing the titanium sheet covered with the TiO2 nanotube film, and taking out a substrate sample for later use;

step (2): preparing CdS nano-particles by adopting a continuous ion layer adsorption method, circularly soaking the substrate sample obtained in the step (1) in Cd (NO3)2 solution, distilled water, Na2S solution and distilled water in sequence, soaking each solution for 1min, circularly soaking the four solutions in sequence for 15 times, drying, and taking out the substrate sample for later use;

and (3): and (3) putting the substrate sample obtained in the step (2) into a reaction kettle, preparing a ZnFe2O4 nanosheet by adopting a hydrothermal method, washing the product, and drying to obtain the ternary composite film.

Preferably, in step (1), the TiO2 nanotubes are prepared by using ammonium fluoride as a raw material and 97% ethylene glycol aqueous solution as a solvent.

Preferably, in the step (1), the anodic oxidation method is carried out under the reaction condition of 20V voltage and the reaction time is 1h, 2h and 3 h; the calcining temperature is 450 ℃, and the annealing time is 2 h. The experimental result shows that TiO2 forms the nanotube best under the condition of 20V and 1 h.

Preferably, in the step (2), the CdS nanoparticles are prepared by using cadmium nitrate and sodium sulfide as raw materials and using water as a solvent.

Preferably, in the step (3), the raw materials used for preparing the ZnFe2O4 nanosheets are ferric nitrate and zinc nitrate, and the solvent used is water.

Preferably, in the step (3), the reaction temperature of the hydrothermal method is 100 ℃, and the reaction time is 5h, 10h and 15h respectively; the drying temperature is 60 ℃, and the annealing time is 4 h. The experimental result shows that the ZnFe2O4 nanosheet formed under the conditions of 100 ℃ and 10h is the best.

The application of the ternary semiconductor composite film is characterized in that the prepared ternary semiconductor composite film is used as a photocathode protective material for protecting stainless steel.

Because of the low cost, non-toxicity and good stability of the TiO 2-based nano material, the corrosion resistance of the stainless steel is improved by compounding TiO2 and some semiconductors to form a heterostructure by using a photo-generated cathodic protection technology.

The invention has the beneficial effects that: TiO2, TiO2/CdS, TiO2/CdS/ZnFe2O4 films are sequentially prepared on a titanium sheet through an anodic oxidation method, a continuous ion layer adsorption method, a hydrothermal method and the like, and the photoelectrochemical property and the photoproduction cathodic protection performance of the TiO2/CdS/ZnFe2O4 film are remarkably improved compared with those of a single TiO2 sample, so that the film has excellent anticorrosion protection performance on stainless steel.

Drawings

FIG. 1 is an SEM image of a single film of TiO2 provided in example 1 of the present invention;

FIG. 2 is an SEM image of a TiO2/CdS composite film provided in example 1 of the present invention;

FIG. 3 is an SEM image of a TiO2/CdS/ZnFe2O4 composite film provided in example 1 of the present invention;

FIG. 4 is an XRD diagram of the TiO2/CdS/ZnFe2O4 composite film provided in example 1 of the present invention;

FIG. 5 is a diagram of the UV-Vis spectra of the TiO2/CdS/ZnFe2O4 composite film, TiO2 and TiO2/CdS provided in example 1 of the present invention;

FIG. 6 is an I-T plot of the TiO2/CdS/ZnFe2O4 composite film, TiO2 and TiO2/CdS provided in example 1 of the present invention;

FIG. 7 is a diagram of OCP under illumination conditions, where the TiO2/CdS/ZnFe2O4 composite film, TiO2 and TiO2/CdS provided in example 1 of the present invention are coupled with 304 SS;

FIG. 8 is Tafel plot of TiO2/CdS/ZnFe2O4 composite film and TiO2, TiO2/CdS coupled with 304SS under illumination conditions, provided in example 1 of the present invention;

FIG. 9 is an impedance diagram of the TiO2/CdS/ZnFe2O4 composite film, TiO2 and TiO2/CdS coupled with 304SS under dark conditions, provided in example 1 of the present invention.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The components, structures, mechanisms and the like described in the following examples are all conventional commercially available products unless otherwise specified.