阅读说明：本技术 光吸收材料及其制备方法 (Light absorbing material and method for producing the same ) 是由 黄春明 于 2020-08-06 设计创作，主要内容包括：本发明涉及光吸收材料及其制备方法,属于功能材料技术领域。本发明解决的技术问题是提供一种能够高效捕获紫外可见红外光谱的新型光吸收材料,该材料为VO<Sub>x</Sub>粉体,其中,2＜x≤2.5。本发明首次提出以水热合成方法来制备该光吸收材料,所制得的粉体对紫外可见近中红外光具有很强的吸收,其制备条件和工艺简单易控,对环境无污染,原料来源广且廉价,有利于规模化生产。制得的VO<Sub>x</Sub>光催化剂对太阳光有全吸收,提高了太阳能的利用率,增强了催化效率,从而可有效降解空气污染物,适用于催化剂和光解水制氢领域。此外,所制得的VO<Sub>x</Sub>粉体在近中红外吸收强度高,能应用于红外光吸收、防红外辐射等领域。(The invention relates to a light absorption material and a preparation method thereof, belonging to the technical field of functional materials. The invention aims to provide a novel light absorption material capable of efficiently capturing ultraviolet visible infrared spectrum, wherein the material is VO x Powder, wherein x is more than 2 and less than or equal to 2.5. The invention firstly proposes that the light absorption material is prepared by a hydrothermal synthesis method, the prepared powder has strong absorption to ultraviolet visible near-middle infrared light, the preparation conditions and the process are simple and easy to control, no pollution is caused to the environment, the raw material source is wide and cheap, and the large-scale production is facilitated. Prepared VO x The photocatalyst has full absorption to sunlight, improves the utilization rate of solar energy, enhances the catalytic efficiency, can effectively degrade air pollutants, and is suitable for the fields of catalysts and hydrogen production by water photolysis. Furthermore, the VO produced x The powder has high near-middle infrared absorption intensity, and can be applied to the fields of infrared absorption, infrared radiation prevention and the like.)

1. A light absorbing material characterized by: the material is VO_xPowder, wherein x is more than 2 and less than or equal to 2.5.

2. A light-absorbing material in accordance with claim 1, wherein: the material can absorb ultraviolet light, visible light and near-mid infrared light.

3. A light-absorbing material in accordance with claim 1 or 2, wherein: the material is prepared from a vanadium-containing precursor and oxalic acid through a hydrothermal reaction, wherein the temperature of the hydrothermal reaction is 220-250 ℃, and the molar ratio of vanadium in the vanadium-containing precursor to carbon in the oxalic acid is 1 (1.5-3.5).

4. A light-absorbing material in accordance with claim 3, wherein: the vanadium-containing precursor comprises any one of vanadium pentoxide and ammonium metavanadate.

5. A light-absorbing material in accordance with claim 3 or 4, wherein: the reaction time of the hydrothermal reaction is 24-72 hours.

6. The preparation method of the light absorption material is characterized by comprising the following steps:

1) mixing materials: mixing the oxalic acid solution and the vanadium-containing precursor, and fully stirring to obtain sol; wherein the molar ratio of vanadium in the vanadium-containing precursor to carbon in the oxalic acid is 1 (1.5-3.5); the vanadium-containing precursor comprises any one of vanadium pentoxide and ammonium metavanadate;

2) hydrothermal reaction: reacting the sol obtained in the step 1) at 220-250 ℃ for 24-72 hours to obtain a crude product;

3) and (3) post-reaction treatment: and washing and drying the crude product to obtain the light absorption material.

7. The method for producing a light-absorbing material according to claim 6, wherein: in the step 1), the concentration of the oxalic acid solution is 0.2-1 mol/L.

8. The method for producing a light-absorbing material according to claim 6 or 7, characterized in that: in the step 3), the washing is alternately centrifugal cleaning by using deionized water and absolute ethyl alcohol.

9. The method for producing a light-absorbing material according to any one of claims 6 to 8, wherein: in the step 3), the drying temperature is 50-150 ℃, and the drying time is 6-24 hours.

Technical Field

The invention relates to a light absorption material and a preparation method thereof, in particular to a novel ultraviolet-visible near-middle infrared light absorption material VO_xAnd a preparation method thereof, belonging to the technical field of functional materials.

Background

The photocatalysis technology is a green technology with important application prospect in the field of energy and environment, and takes a semiconductor as a catalyst to carry out a series of oxidation-reduction reactions by absorbing external sunlight so as to achieve the effect of degrading pollutants. As a common pollutant degradation mode, the photocatalytic technology has attracted attention because it can effectively degrade organic pollutants such as rhodamine B, methyl orange, phenol, and the like. In addition, the photocatalysis technology can also utilize solar photocatalysis to crack water to generate hydrogen energy, and is expected to solve the energy crisis problem. The existing semiconductor catalyst can only utilize about 5 percent of ultraviolet light and about 46 percent of visible light in sunlight, and still about 49 percent of near-middle infrared light is not utilized, so that the utilization rate of the sunlight is greatly reduced. On the other hand, most semiconductor catalysts can only absorb and utilize part of light energy but not all solar energy, for example, titanium dioxide can only absorb and utilize ultraviolet light, iron oxide can only absorb and utilize visible light, and manganese oxide can only absorb and utilize near-infrared light. Therefore, how to find a photocatalyst capable of efficiently capturing ultraviolet, visible and infrared spectrums becomes a main way for improving the photocatalytic efficiency.

A Chinese patent with the application number of 201811030034.X discloses a full-spectrum response carbon dioxide reduction composite photocatalyst and a preparation method thereof, wherein the composite photocatalyst is Cu₂In₂ZnS₅/Gd₂O₂Tb complex, Gd₂O₂Tb dispersed in Cu₂In₂ZnS₅Upper, Cu₂In₂ZnS₅Is a two-dimensional sheet structure of Gd₂O₂Tb is Gd₂O₂S, Tb nano-sheet is agglomerated. The Chinese invention patent with application number of 201811124607.5 discloses a preparation method of a black titanium dioxide nano composite material with an imitation moth-eye nano structure, which takes carbon cloth as a substrate material to provide a good diffusion channel for the dispersion of solar energy steam; the titanium dioxide nano composite material with the moth-eye-imitated nano structure introduces oxygen vacancies and a surface disordered structure on the surface of the carbon cloth through the reduction reaction of a reducing agent. The invention patent with the application number of 201710213349.7 discloses a high-efficiency full-spectral response CuS/graphene composite photocatalyst and a preparation method thereof, wherein the composite photocatalyst is formed by attaching CuS microspheres on graphene sheets, the graphene is of a two-dimensional sheet structure, and the CuS microspheres are assembled by CuS nanoparticles. The invention patent with application number 201010247518.7 discloses a preparation method and application of a photocatalytic material with ultraviolet visible full spectrum.The material is a nano material which takes bismuth oxychloride as a substrate and is doped with one or two elements of bromine and iodine.

Therefore, the full-spectrum photocatalytic material has less research, the preparation method is more complex, the cost is higher, and the large-scale industrial application cannot be realized.

Disclosure of Invention

Aiming at the defects, the first technical problem solved by the invention is to provide a novel light absorption material capable of efficiently capturing ultraviolet visible infrared spectra, and the material is simple in preparation method and low in cost.

The light absorbing material of the invention is VO_xPowder, wherein x is more than 2 and less than or equal to 2.5.

Preferably, the material absorbs ultraviolet, visible and near-mid infrared light.

Preferably, the material is prepared by carrying out hydrothermal reaction on a vanadium-containing precursor and oxalic acid, wherein the temperature of the hydrothermal reaction is 220-250 ℃, and the molar ratio of vanadium in the vanadium-containing precursor to carbon in the oxalic acid is 1 (1.5-3.5).

Preferably, the vanadium-containing precursor includes any one of vanadium pentoxide and ammonium metavanadate.

Preferably, the reaction time of the hydrothermal reaction is 24 to 72 hours.

The second technical problem solved by the invention is to provide a preparation method of the light absorption material.

The preparation method of the light absorption material comprises the following steps:

1) mixing materials: mixing the oxalic acid solution and the vanadium-containing precursor, and fully stirring to obtain sol; wherein the molar ratio of vanadium in the vanadium-containing precursor to carbon in the oxalic acid is 1 (1.5-3.5); the vanadium-containing precursor comprises any one of vanadium pentoxide and ammonium metavanadate;

2) hydrothermal reaction: reacting the sol obtained in the step 1) at 220-250 ℃ for 24-72 hours to obtain a crude product;

3) and (3) post-reaction treatment: and washing and drying the crude product to obtain the light absorption material.

Preferably, in the step 1), the concentration of the oxalic acid solution is 0.2-1 mol/L.

Preferably, in the step 3), the washing is centrifugal washing with deionized water and absolute ethyl alcohol alternately.

Preferably, in the step 3), the drying temperature is 50-150 ℃ and the drying time is 6-24 hours.

Compared with the prior art, the invention has the following beneficial effects:

the invention provides a method for preparing a novel ultraviolet visible infrared light absorbing material VO by a hydrothermal synthesis method_xThe powder prepared has strong absorption to ultraviolet visible near-middle infrared light.

The method has the advantages of simple and easily-controlled preparation conditions and process, no environmental pollution, wide and cheap raw material sources and contribution to large-scale production. Preparation of VO by hydrothermal method_xThe powder is finished in liquid phase at one time, the product has uniform granularity, and impurities are not easy to be mixed. Prepared VO_xThe photocatalyst has full absorption to sunlight, improves the utilization rate of solar energy, enhances the catalytic efficiency, can effectively degrade air pollutants, and is suitable for the fields of catalysts and hydrogen production by water photolysis. Furthermore, the VO produced_xThe powder has high near-middle infrared absorption intensity, and can be applied to the fields of infrared absorption, infrared radiation prevention and the like.

Drawings

FIG. 1 shows VO prepared in example 1 of the present invention_xScanning electron micrographs of the powder.

FIG. 2 shows VO prepared in example 1 of the present invention_xXRD pattern of the powder.

FIG. 3 shows VO prepared in example 1 of the present invention_xAnd (3) selecting an electronic diffraction pattern of the powder.

FIG. 4 shows VO prepared in example 1 of the present invention_xEDS spectrum of powder.

FIG. 5 shows VO prepared in example 1 of the present invention_xThe powder has an X-ray photoelectron spectrum (V2p 3/2).

FIG. 6 shows VO prepared in example 1 of the present invention_xReflection spectrum of the powder.

FIG. 7 shows VO prepared in example 2 of the present invention_xXRD pattern of the powder.

FIG. 8 shows an embodiment of the present inventionExample 2 preparation of VO_xReflection spectrum of the powder.

FIG. 9 shows VO prepared in example 7 of the present invention_xXRD pattern of the powder.

FIG. 10 shows VO prepared in example 9 of the present invention_xReflection spectrum of the powder.

FIG. 11 shows VO prepared in example 10 of the present invention_xReflection spectrum of the powder.

FIG. 12 shows VO prepared in example 13 of the present invention_xXRD pattern of the powder.

FIG. 13 shows VO prepared in example 13 of the present invention_xReflection spectrum of the powder.

FIG. 14 shows VO prepared in example 14 of the present invention_xReflection spectrum of the powder.

FIG. 15 shows VO prepared in example 16 of the present invention_xXRD pattern of the powder.

FIG. 16 shows VO prepared in example 17 of the present invention₂XRD pattern of the powder.

Detailed Description

The light absorbing material of the invention is VO_xPowder, wherein x is more than 2 and less than or equal to 2.5.

The light absorption material can absorb ultraviolet light, visible light and near-mid infrared light. The material has strong absorption to ultraviolet visible near-middle infrared light, and can be used in the fields of photocatalyst, hydrogen production by water photolysis, infrared light absorption, infrared radiation prevention and the like.

The light absorption material is prepared from a vanadium-containing precursor and oxalic acid through a hydrothermal reaction, wherein the temperature of the hydrothermal reaction is 220-250 ℃, and the molar ratio of vanadium in the vanadium-containing precursor to carbon in the oxalic acid is 1 (1.5-3.5).

Wherein, different from the common hydrothermal method for reducing pentavalent vanadium compounds, the reaction temperature of the light absorption material of the invention is higher, and the chemical mixture ratio of the raw materials and the reaction temperature are controlled, so as to obtain a brand new vanadium oxide VO_xComparison of existing phase database, VO_xIs a novel artificially synthesized vanadium oxide. On the other hand, when the reaction temperature is lowered, VO having excellent light absorption properties according to the present invention cannot be produced_xAnd (3) powder.

Common vanadium-containing precursors are suitable for the present invention, and preferably, the vanadium-containing precursor includes any one of vanadium pentoxide and ammonium metavanadate.

Preferably, the reaction time of the hydrothermal reaction is 24 to 72 hours.

The preparation method of the light absorption material comprises the following steps:

1) mixing materials: mixing the oxalic acid solution and the vanadium-containing precursor, and fully stirring to obtain sol; wherein the molar ratio of vanadium in the vanadium-containing precursor to carbon in the oxalic acid is 1 (1.5-3.5); the vanadium-containing precursor comprises any one of vanadium pentoxide and ammonium metavanadate;

2) hydrothermal reaction: reacting the sol obtained in the step 1) at 220-250 ℃ for 24-72 hours to obtain a crude product;

3) and (3) post-reaction treatment: and washing and drying the crude product to obtain the light absorption material.

The method of the invention is to add oxalic acid (H) according to the preset V: C molar ratio₂C₂O₄) Adding a vanadium-containing precursor into the deionized water solution, uniformly stirring to obtain sol, and transferring the sol into a hydrothermal kettle for hydrothermal reaction to obtain a hydrothermal product; the hydrothermal product is cooled, washed to neutrality by water and ethanol, and dried to obtain the required material with full spectrum high absorption to ultraviolet light, visible light and near-mid infrared light. The method has the advantages of simple and easily-controlled preparation conditions and process, no environmental pollution, wide and cheap raw material sources, and is beneficial to large-scale production. And the reaction is finished in a liquid phase at one time, the product has uniform granularity, and impurities are not easy to mix.

Preferably, in the step 1), the concentration of the oxalic acid solution is 0.2-1 mol/L.

Washing methods commonly used in the art are suitable for the present invention, and preferably, in step 3), the washing is centrifugal washing with deionized water and absolute ethyl alcohol alternately for several times.

The method has no special requirement on drying, and as an optimal scheme, in the step 3), the drying temperature is 50-150 ℃, and the drying time is 6-24 hours.

In some embodiments of the invention, the invention employs the following specific process:

(1) configuration H₂C₂O₄Solution: weighing a certain amount of H₂C₂O₄Putting the blocky solid in a beaker, weighing a certain volume of deionized water by using a measuring cylinder, pouring the deionized water into the beaker, and putting the beaker on a magnetic stirrer for stirring;

(2) weighing a certain amount of vanadium-containing precursor (V) according to a preset V to C molar ratio₂O₅Or NH₄VO₃) Pouring a certain volume of the solution prepared in the step 1) and putting the solution in a magnetic stirrer for fully stirring to obtain the required sol; the preferable proportion of the raw materials is as follows: the molar ratio of V to C is 1: (1.5-3.5);

(3) washing the inner container of the hydrothermal reaction kettle with deionized water and absolute ethyl alcohol, and pouring the sol prepared in the step 2) into the inner container of the hydrothermal reaction kettle;

(4) the inner container is put into a reaction kettle to be sealed, and is put into a drying box to be set at a certain temperature and time for hydrothermal reaction; the temperature of the hydrothermal reaction is 220-250 ℃, and the time is 24-72 hours;

(5) taking out the reactant from the inner container after the reaction is finished, alternately centrifugally cleaning for a plurality of times by using deionized water and absolute ethyl alcohol, and finally drying in a drying oven for a certain time to obtain a required product; the drying temperature is 50-150 ℃, and the drying time is 6-24 hours.

The following examples are provided to further illustrate the embodiments of the present invention and are not intended to limit the scope of the present invention. Chemical raw material H used in examples₂C₂O₄，V₂O₅And NH₄VO₃All are analytically pure.