阅读说明：本技术 海绵状二氧化钛多孔层的制备方法 (Preparation method of spongy titanium dioxide porous layer ) 是由 张少瑜 王建玉 胡冬艳 孟祥军 夏小平 于 2021-08-25 设计创作，主要内容包括：本申请公开了一种海绵状二氧化钛多孔层的制备方法,包括如下步骤,电极制备步骤：将钛箔进行抛光处理,而后用去离子水洗干净；电解液配制步骤：配制电解液,所述电解液中含有氟硅酸；电解液老化步骤：将抛光后的钛箔置于电解液中作为正极,石墨电极作为负极,正负极之间加上恒流电流,反应一段时间后取出；多孔层制备步骤：将抛光后的钛箔置于电解液中作为正极,石墨电极作为负极,正负极之间加上恒流电流,反应一段时间后取出。本发明具有如下有益效果：通过采用含有氟硅酸的电解液,使电解液中氟离子的浓度稳定维持在较低水平,控制离子电流的量,增加电子电流的量,使氧气泡呈现出多处随机产生,从而制得孔径较小的海绵状形貌。(The application discloses a preparation method of a spongy titanium dioxide porous layer, which comprises the following steps: polishing the titanium foil, and then washing the titanium foil clean by deionized water; preparing an electrolyte: preparing an electrolyte, wherein the electrolyte contains fluosilicic acid; and (3) electrolyte aging: placing the polished titanium foil in electrolyte as a positive electrode, taking a graphite electrode as a negative electrode, applying constant current between the positive electrode and the negative electrode, reacting for a period of time, and taking out; a porous layer preparation step: and placing the polished titanium foil in electrolyte to serve as a positive electrode, taking a graphite electrode as a negative electrode, applying constant current between the positive electrode and the negative electrode, reacting for a period of time, and taking out. The invention has the following beneficial effects: by adopting the electrolyte containing fluosilicic acid, the concentration of fluorine ions in the electrolyte is stably maintained at a lower level, the amount of ionic current is controlled, the amount of electronic current is increased, and oxygen bubbles are randomly generated at multiple positions, so that the spongy morphology with small pore diameter is prepared.)

1. A method for preparing a spongy titanium dioxide porous layer is characterized by comprising the following steps,

the preparation method of the electrode comprises the following steps: polishing the titanium foil, and then washing the titanium foil clean by deionized water;

preparing an electrolyte: preparing an electrolyte, wherein the electrolyte contains fluosilicic acid;

and (3) electrolyte aging: placing the polished titanium foil in electrolyte as a positive electrode, taking a graphite electrode as a negative electrode, applying constant current between the positive electrode and the negative electrode, reacting for a period of time, and taking out;

a porous layer preparation step: and placing the polished titanium foil in electrolyte to serve as a positive electrode, a graphite electrode as a negative electrode, applying constant current between the positive electrode and the negative electrode, reacting for a period of time, taking out, washing with deionized water, and airing.

2. The method for producing a porous sponge-like titanium dioxide layer according to claim 1, wherein in the electrode production step, polishing is performed with a mixed solution of hydrofluoric acid and nitric acid.

3. The method for producing a porous sponge-like titanium dioxide layer according to claim 1, wherein the volume ratio of hydrofluoric acid to nitric acid is 1: 3.

4. the method for producing a porous sponge-like titanium dioxide layer according to claim 1, wherein said electrolyte comprises ethylene glycol, ammonium fluoride, deionized water and fluorosilicic acid.

5. The method for producing a porous sponge-like titanium dioxide layer according to claim 1, wherein a constant current of 3mA/cm2 is applied between the positive and negative electrodes in the electrolyte aging step.

6. The method for producing a porous sponge-like titanium dioxide layer according to claim 5, wherein the energization reaction time in the electrolyte aging step is 20 min.

7. The method for producing a porous titania layer in a sponge form as claimed in claim 1, wherein 2mA/cm is added between the positive and negative electrodes in the porous layer producing step²The constant current of (1).

8. The method for producing a porous titania layer in a sponge form according to claim 7, wherein the energization time in the porous layer producing step is 30 min.

Technical Field

The invention relates to the field of nano materials, in particular to a preparation method of a spongy titanium dioxide porous layer.

Background

Titanium dioxide is a semiconductor material with a great number of applications, and porous titanium dioxide has wide application in the fields of heterogeneous catalysis, gas sensitivity and the like. At present, the most applied titanium dioxide materials are mainly nanotubes, nanowires and the like, but the specific surface area of the nanotube or nanowire-shaped titanium dioxide material is small, and the loading capacity is small when the nanotube or nanowire-shaped titanium dioxide material is used as a carrier.

Patent CN107552079B provides a method for preparing titanium dioxide photocatalyst with sponge-like porous structure, the titanium dioxide of this structure has relatively high specific surface area, but this preparation method needs calcination, so it not only has good preparation but also has great safety hazard.

Disclosure of Invention

The invention provides a preparation method of a spongy titanium dioxide porous layer aiming at the problems.

The technical scheme adopted by the invention is as follows:

a preparation method of a spongy titanium dioxide porous layer comprises the following steps,

the preparation method of the electrode comprises the following steps: polishing the titanium foil, and then washing the titanium foil clean by deionized water;

preparing an electrolyte: preparing an electrolyte, wherein the electrolyte contains fluosilicic acid;

and (3) electrolyte aging: placing the polished titanium foil in electrolyte as a positive electrode, taking a graphite electrode as a negative electrode, applying constant current between the positive electrode and the negative electrode, reacting for a period of time, and taking out;

a porous layer preparation step: and placing the polished titanium foil in electrolyte to serve as a positive electrode, a graphite electrode as a negative electrode, applying constant current between the positive electrode and the negative electrode, reacting for a period of time, taking out, washing with deionized water, and airing.

In the preparation method, the electrolyte containing fluosilicic acid is adopted, so that the concentration of fluorine ions in the electrolyte is stably maintained at a lower level, the amount of ionic current is controlled, the amount of electronic current is increased, and oxygen bubbles are generated randomly at multiple positions and can escape in a smaller volume, thereby preparing the spongy morphology with smaller pore diameter.

Optionally, in the electrode preparation step, a mixed solution of hydrofluoric acid and nitric acid is used for polishing.

Optionally, the volume ratio of the hydrofluoric acid to the nitric acid is 1: 3.

optionally, the electrolyte includes ethylene glycol, ammonium fluoride, deionized water, and fluorosilicic acid.

Optionally, a constant current of 3mA/cm2 is applied between the anode and the cathode in the electrolyte aging step.

Optionally, the electrifying reaction time in the electrolyte aging step is 20 min.

Optionally, a constant current of 2mA/cm2 is added between the positive electrode and the negative electrode in the porous layer preparation step.

Optionally, the current flowing time in the porous layer preparation step is 30 min.

The invention has the beneficial effects that: by adopting the electrolyte containing fluosilicic acid, the concentration of fluorine ions in the electrolyte is stably maintained at a lower level, the amount of ionic current is controlled, the amount of electronic current is increased, and oxygen bubbles are randomly generated at multiple positions and can escape in a smaller volume, so that the spongy morphology with smaller pore diameter is prepared.

Description of the drawings:

FIG. 1 is an electron micrograph of a porous layer of spongy titanium dioxide,

FIG. 2 is an electron micrograph of a porous layer of titania prepared by conventional anodization.

The specific implementation mode is as follows:

the present invention will be described in detail below with reference to examples and electron micrographs.

Example 1

Step 1, preparing an electrode: polishing the titanium foil in hydrofluoric acid and nitric acid polishing solution with the volume ratio of 1:3 for 10s, taking out and cleaning with deionized water.

Step 2, preparing electrolyte 1: 0.1mol/L of ammonium fluoride and deionized water with the mass ratio of 2% are added into ethylene glycol. Preparation of electrolyte 2: deionized water and 0.03mol/L fluosilicic acid are added into the ethylene glycol according to the mass ratio of 2 percent.

And 3, aging of the electrolyte: placing the polished titanium foil in the electrolyte 1 as a positive electrode, a graphite electrode as a negative electrode, and adding 3mA/cm between the positive electrode and the negative electrode²Reacting for 20min, and taking out.

Step 4, preparing a spongy anode titanium dioxide porous layer: the step is similar to the step 3, the polished titanium foil is placed in the electrolyte 2 to be used as a positive electrode, the graphite electrode is used as a negative electrode, and 2mA/cm is added between the positive electrode and the negative electrode²Reacting for 30min, taking out, washing with deionized water, and air drying to obtain the porous titanium dioxide layer.

An electron micrograph of the titania porous layer prepared in this example is shown in FIG. 1.

Comparative example

The traditional anodic oxidation process:

step 1, preparing an electrode: polishing the titanium foil in hydrofluoric acid and nitric acid polishing solution with the volume ratio of 1:3 for 10s, taking out and cleaning with deionized water.

Step 2, preparing electrolyte: 0.1mol/L of ammonium fluoride and deionized water with the mass ratio of 2% are added into ethylene glycol.

And 3, aging of the electrolyte: placing the polished titanium foil in electrolyte as a positive electrode, a graphite electrode as a negative electrode, and adding 10mA/cm between the positive electrode and the negative electrode²Reacting for 20min, and taking out.

Step 4, preparing the anode titanium dioxide nanotube: the step is similar to the step 3, the polished titanium foil is placed in electrolyte to be used as a positive electrode, a graphite electrode is used as a negative electrode, and 10mA/cm is added between the positive electrode and the negative electrode²Reacting for 30min, taking out, washing with deionized water, and air drying to obtain the final product.

An electron micrograph of the titania porous layer prepared in this comparative example is shown in FIG. 2.

By comparing the embodiment 1 with the comparison example and comparing the attached drawings 1 and 2, the technical scheme of the invention has the following advantages: 1. ammonium fluoride is changed into fluosilicic acid, so that the concentration of fluorine ions in the electrolyte is stably maintained at a lower level; 2. a smaller anodization current is used to avoid breakdown or formation of large bubbles.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, which is defined by the claims and their equivalents, and can be directly or indirectly applied to other related fields of technology.