阅读说明：本技术 碘氧化铋/氧化锌复合材料及其制备方法与在压电-光催化去除有机污染物中的应用 (Bismuth oxyiodide/zinc oxide composite material, preparation method thereof and application thereof in piezoelectric-photocatalytic removal of organic pollutants ) 是由 路建美 李娜君 于 2019-11-08 设计创作，主要内容包括：本发明公开了碘氧化铋/氧化锌复合材料及其制备方法与在压电-光催化去除有机污染物中的应用；将旋涂氧化锌晶种溶液的导电基底退火处理后加入前驱体溶液中,反应后得到氧化锌纳米棒阵列(ZnO NRs)；将氧化锌纳米棒阵列加入碘氧化铋前驱体溶液中,反应得到碘氧化铋/氧化锌复合材料(BiOI/ZnO NAs)。将本发明纳米复合材料放入含有双酚A的水溶液中,避光吸附半小时后用超声和可见光共同作用,实现水中有机污染物的去除,在压电-光催化降解90分钟后,水溶液中的双酚A几乎完全降解。(The invention discloses a bismuth oxyiodide/zinc oxide composite material, a preparation method thereof and application thereof in removing organic pollutants by piezoelectric-photocatalysis; annealing the conductive substrate coated with the zinc oxide seed crystal solution, adding the conductive substrate into the precursor solution, and reacting to obtain a zinc oxide nanorod array (ZnO NRs); and adding the zinc oxide nanorod array into a bismuth oxyiodide precursor solution, and reacting to obtain the bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs). The nano composite material is put into a water solution containing bisphenol A, is adsorbed for half an hour in the dark, and then is subjected to the combined action of ultrasound and visible light to remove organic pollutants in water, and after 90 minutes of piezoelectric-photocatalytic degradation, the bisphenol A in the water solution is almost completely degraded.)

1. The bismuth oxyiodide/zinc oxide composite material is characterized in that the preparation method of the bismuth oxyiodide/zinc oxide composite material comprises the following steps:

(1) annealing the conductive substrate coated with the zinc oxide seed crystal solution, adding the conductive substrate into the precursor solution, and reacting to obtain a zinc oxide nanorod array;

(2) and adding the zinc oxide nanorod array into a bismuth oxyiodide precursor solution, and reacting to obtain the bismuth oxyiodide/zinc oxide composite material.

2. The bismuth oxyiodide/zinc oxide composite material according to claim 1, wherein in the step (1), the zinc oxide seed solution is composed of an aqueous zinc salt solution and an aqueous amine compound solution; the precursor solution consists of water soluble zinc salt, amine compound and water.

3. The bismuth oxyiodide/zinc oxide composite material according to claim 2, wherein the concentration of the zinc salt aqueous solution is (0.14-0.15) g/mL, and the concentration of the amine compound aqueous solution is (0.07-0.071) g/mL; in the precursor solution, the mass ratio of the water-soluble zinc salt to the amine compound to the water is (0.74-0.75) to (0.35-0.36) to 100.

4. The bismuth oxyiodide/zinc oxide composite material according to claim 1, wherein in the step (1), the conductive substrate is indium tin oxide glass; the annealing treatment is that the temperature is kept for 10 to 35 minutes at 300 to 350 ℃ in the air atmosphere, and the heating rate is 4 to 6 ℃/min; the reaction is carried out for 5-9 h at 80-120 ℃.

5. The bismuth oxyiodide/zinc oxide composite material according to claim 4, wherein the annealing treatment is heat preservation at 320 ℃ for 30 minutes in an air atmosphere, and the temperature rise rate is 5 ℃/min; the reaction is carried out for 6 h at 90 ℃.

6. The bismuth oxyiodide/zinc oxide composite material according to claim 1, wherein in the step (2), the bismuth oxyiodide precursor solution is composed of a water-soluble bismuth salt, an iodonium salt, and an organic solvent; the reaction is carried out at 120-180 ℃ for 10-15 h.

7. The bismuth oxyiodide/zinc oxide composite material as claimed in claim 6, wherein the dosage ratio of the water-soluble bismuth salt to the organic solvent is (48-49) mg: 40 ml; the water-soluble bismuth salt, the iodine salt and the organic solvent are respectively bismuth nitrate pentahydrate, potassium iodide and ethylene glycol monomethyl ether; the reaction is carried out for 12h at 160 ℃.

8. Use of the bismuth oxyiodide/zinc oxide composite material according to claim 1 for the degradation of organic pollutants.

9. Use according to claim 8, wherein the organic contaminant is bisphenol A.

10. The preparation method of the bismuth oxyiodide/zinc oxide composite material is characterized by comprising the following steps of:

(1) annealing the conductive substrate coated with the zinc oxide seed crystal solution, adding the conductive substrate into the precursor solution, and reacting to obtain a zinc oxide nanorod array;

(2) and adding the zinc oxide nanorod array into a bismuth oxyiodide precursor solution, and reacting to obtain the bismuth oxyiodide/zinc oxide composite material.

Technical Field

The invention relates to the technical field of nano composite materials and piezoelectricity-photocatalysis, in particular to a preparation method of a one-dimensional zinc oxide nano-rod array and a two-dimensional bismuth oxyiodide nano-composite material and application thereof in effectively removing water pollutants through piezoelectricity-photocatalysis.

Background

Environmental pollution and destruction and shortage of clean energy are the most serious problems facing the world at present. How to effectively treat environmental pollution in a green way becomes a global research hotspot. Photocatalytic technology is a significant advance in this area and is a sustainable, harmless and economically viable advanced technology. This technology can utilize inexhaustible, safe and clean energy from the sun. In addition, zinc oxide exhibits an ultraviolet response due to a wide band gap, which greatly reduces the efficiency of utilization of sunlight.

Disclosure of Invention

The invention aims to provide a composite material responding to visible light, which can quickly and effectively degrade pollutants in a water body through the synergistic effect of ultrasound and photocatalysis. The catalytic performance of the composite material prepared by the invention is researched by taking bisphenol A as a target organic pollutant. The bismuth oxyiodide/zinc oxide composite material disclosed by the invention has the advantages that under the action of an external force, an electric field is formed in the bismuth oxyiodide/zinc oxide composite material, free carriers are effectively separated, the recombination of the carriers is inhibited, the catalytic degradation of organic pollutants under the condition of no light is realized, the degradation performance is improved through photocatalysis in cooperation with piezoelectric catalysis, under the combined action of the external force and light, the material is excited to generate photo-generated electron hole pairs, the photo-generated electron hole pairs are quickly and effectively separated through the piezoelectric internal electric field, and the photocatalytic performance is enhanced; has chemical stability, high reaction activity and piezoelectricity, and has excellent application value in the fields of photocatalysis and piezoelectric catalysis.

In order to achieve the purpose, the specific technical scheme of the invention is as follows:

the preparation method of the bismuth oxyiodide/zinc oxide composite material comprises the following steps:

(1) annealing the conductive substrate coated with the zinc oxide seed crystal solution, adding the conductive substrate into the precursor solution, and reacting to obtain a zinc oxide nanorod array (ZnO NRs);

(2) and adding the zinc oxide nanorod array into a bismuth oxyiodide precursor solution, and reacting to obtain the bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs).

The invention discloses a method for degrading organic pollutants, which comprises the following steps:

(1) annealing the conductive substrate coated with the zinc oxide seed crystal solution, adding the conductive substrate into the precursor solution, and reacting to obtain a zinc oxide nanorod array (ZnO NRs);

(2) adding the zinc oxide nanorod array into a bismuth oxyiodide precursor solution, and reacting to obtain a bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs);

(3) the bismuth oxyiodide/zinc oxide composite material is put into a solution containing organic pollutants, and the degradation of the organic pollutants is realized under the combined action of ultrasound and illumination.

In the invention, in the step (1), the zinc oxide seed crystal solution consists of a zinc salt aqueous solution and an amine compound aqueous solution, preferably, the concentration of the zinc salt aqueous solution is (0.14-0.15) g/mL, and the concentration of the amine compound aqueous solution is (0.07-0.071) g/mL; the precursor solution consists of water-soluble zinc salt, amine compound and water, and the mass ratio of the water-soluble zinc salt to the amine compound to the water is preferably (0.74-0.75) to (0.35-0.36) to 100. The zinc oxide seed crystal solution and the precursor solution have the same raw material but different concentrations. Wherein the water-soluble zinc salt is zinc nitrate hexahydrate, and the amine compound is hexamethylenetetramine.

In the invention, in the step (1), the conductive substrate is Indium Tin Oxide (ITO) glass; the annealing treatment is that the temperature is kept for 10-35 minutes at 300-350 ℃ in air atmosphere, the heating rate is 4-6 ℃/min, preferably, the temperature is kept for 30 minutes at 320 ℃ in air atmosphere, and the heating rate is 5 ℃/min; the reaction is carried out for 5-9 h at 80-120 ℃, preferably for 6 h at 90 ℃.

In the invention, in the step (2), the bismuth oxyiodide precursor solution consists of water-soluble bismuth salt, iodized salt and an organic solvent, preferably, the dosage ratio of the water-soluble bismuth salt to the organic solvent is (48-49) mg: 40 ml; the water-soluble bismuth salt, the iodine salt and the organic solvent are respectively bismuth nitrate pentahydrate, potassium iodide and ethylene glycol monomethyl ether.

In the invention, in the step (2), the reaction is carried out at 120-180 ℃ for 10-15 h, preferably at 160 ℃ for 12 h.

In the bismuth oxyiodide/zinc oxide composite material, the molar ratio of Bi to Zn is 10-20%.

In the invention, in the step (3), the organic pollutant is bisphenol A; the illumination is visible light illumination; the power of the ultrasound was 90W.

The preparation method of the bismuth oxyiodide/zinc oxide composite material comprises the following steps:

(1) preparing a zinc oxide nanorod array: firstly, spin-coating a zinc oxide seed crystal layer on a cleaned Indium Tin Oxide (ITO) glass conductive surface, and then annealing the spin-coated ITO glass for 10-35 minutes at 300-350 ℃ in air; then placing the annealed ITO glass into a reaction kettle with the conductive surface facing downwards obliquely, adding a precursor solution, namely a zinc nitrate and hexamethylenetetramine aqueous solution, reacting for 5-9 h at 80-120 ℃, taking out the ITO glass after the reaction is finished, washing with deionized water, and drying to obtain a zinc oxide nanorod array (ZnO NRs);

(2) preparing a bismuth oxyiodide/zinc oxide composite material nano array: preparing ethylene glycol monomethyl ether solution of bismuth nitrate pentahydrate and potassium iodide in a molar ratio of 1:1, violently stirring for 15-30 minutes, then pouring into a 50 ml reaction kettle, inserting the ITO glass conductive surface with the zinc oxide nanorod array facing downwards into the reaction kettle in an inclined manner, sealing, and reacting for 10-15 hours at 120-180 ℃. And after natural cooling, taking out the ITO glass, washing with deionized water, and drying to obtain the bismuth oxyiodide/zinc oxide nano-array (BiOI/ZnO NAs).

Piezoelectric synergistic photocatalytic degradation experiment: the nano-array material is put into a water solution containing bisphenol A, and is adsorbed for half an hour in the dark, and then the organic pollutants in the water are removed by the combined action of ultrasound and visible light.

The invention has the advantages that:

1. the invention discloses a bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs) growing on ITO conductive glass, which has a simple synthetic method and a regular shape; the raw materials are commonly and easily obtained; the substrate ITO conductive glass has good conductivity, can promote the transfer and diffusion of electron hole pairs of the composite material, and can effectively improve the photocatalytic performance;

2. the invention discloses a bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs) growing on ITO conductive glass, which can be recycled after a photocatalytic degradation experiment very conveniently due to growing on the ITO glass, and can be recycled only by cleaning with clear water;

3. the invention discloses a bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs) growing on ITO conductive glass, wherein zinc oxide has better piezoelectric property, the photocatalysis property can be effectively improved by introducing ultrasonic assistance, and particularly the rod-shaped zinc oxide has the best performance; after the bismuth oxyiodide is loaded, the photoresponse range of the composite material is expanded, and visible light is fully utilized; meanwhile, the flaky bismuth oxyiodide can provide abundant active sites, and the degradation reaction activity is further promoted.

Drawings

FIG. 1 is a scanning electron micrograph of zinc oxide nanorod arrays (ZnO NRs);

FIG. 2 is a scanning electron micrograph of a zinc oxide-supported bismuth oxyiodide composite (BiOI/ZnO);

FIG. 3 is a transmission electron micrograph of a zinc oxide-supported bismuth oxyiodide composite (BiOI/ZnO);

FIG. 4 is a graph showing the effect of a bismuth oxyiodide-loaded zinc oxide composite material (BiOI/ZnO) on degrading bisphenol A.

Detailed Description

According to the invention, a zinc oxide nanorod array grows on an indium tin oxide glass substrate through a simple hydrothermal method, and then a two-dimensional bismuth oxyiodide nanosheet is loaded on the surface of a one-dimensional zinc oxide nanorod through a solvothermal method, so that the purpose of adjusting the band gap of the composite material is achieved, and the composite material can absorb visible light. By combining the photocatalyst bismuth oxyiodide and the piezoelectric catalyst zinc oxide, the built-in electric field of the piezoelectric material is utilized to promote the migration and separation of photo-generated charges and inhibit the compounding of the charges, so that the photocatalytic activity of the composite material is improved, and organic pollutants in water are degraded quickly and efficiently.

The preparation method of the bismuth oxyiodide/zinc oxide composite material comprises the following steps:

(1) annealing the conductive substrate coated with the zinc oxide seed crystal solution, adding the conductive substrate into the precursor solution, and reacting to obtain a zinc oxide nanorod array (ZnO NRs);

(2) and adding the zinc oxide nanorod array into a bismuth oxyiodide precursor solution, and reacting to obtain the bismuth oxyiodide/zinc oxide composite material (BiOI/ZnO NAs).

Different from the prior art, the zinc oxide nanorod array is added into the solution containing bismuth and iodine at the same time instead of being added step by step, and the obtained product has good performance.