阅读说明：本技术 一种氯掺杂氧化锌纳米棒的制备及应用 (Preparation and application of chlorine-doped zinc oxide nano-rod ) 是由 刘平 袁杰 黄学烟 张璐璐 高帆 雷瑞 叶云 江灿琨 于 2019-10-25 设计创作，主要内容包括：本发明公开了一种氯掺杂氧化锌纳米棒的制备及应用。制得所述氯掺杂氧化锌纳米棒为非中心对称六方纤锌矿结构,在声波的辅助下能够产生压电场,促进光催化废水处理。氯掺杂氧化锌在声波辅助下光催化降解废水速率为0.02315 min<Sup>-1</Sup>,其降解速率为氧化锌在声波辅助下光催化降解废水速率的1.5倍,为氯掺杂氧化锌单独光催化降解速率的4.9倍。本发明方法显著提升了氧化锌材料在光催化降解有机污染物的能力,特别是实现了光能-机械能的双捕获,而且本发明的制备方法简单,适合工业化生产。(The invention discloses a preparation method and application of a chlorine-doped zinc oxide nanorod. The prepared chlorine-doped zinc oxide nano rod is of a non-centrosymmetric hexagonal wurtzite structure, can generate a piezoelectric field under the assistance of sound waves, and promotes photocatalytic wastewater treatment. The photocatalytic degradation rate of the chlorine-doped zinc oxide under the assistance of sound waves for wastewater is 0.02315 min ‑1 The degradation rate is 1.5 times of the photocatalytic wastewater degradation rate of zinc oxide under the assistance of sound waves, and 4.9 times of the single photocatalytic degradation rate of chlorine-doped zinc oxide. The method provided by the invention obviously improves the capacity of the zinc oxide material in photocatalytic degradation of organic pollutants, especially realizes double capture of light energy and mechanical energy, and the preparation method provided by the invention is simple and is suitable for industrial production.)

1. A preparation method of a chlorine-doped zinc oxide nanorod is characterized by comprising the following steps: the length of the chlorine-doped zinc oxide nano rod is 0.5mm-1mm, the diameter is 30nm-60nm, and the structure is a hexagonal wurtzite structure;

the preparation method comprises the following steps:

(1) respectively dissolving zinc stearate and potassium hydroxide in methanol, dropwise adding the methanol solution dissolved with the zinc stearate into the methanol solution dissolved with the potassium hydroxide, and adding the reaction solution by taking zinc chloride as a chlorine source;

(2) and (2) transferring the reaction liquid obtained in the step (1) to a reaction kettle for solvothermal reaction at the temperature of 100 ℃ and 200 ℃ for 24-72 h to obtain the chlorine-doped zinc oxide nanorod.

2. The method of claim 1, wherein: the molar ratio of zinc stearate to potassium hydroxide is 1: 1.

3. the method of claim 1, wherein: the molar ratio of the potassium hydroxide to the zinc chloride is 1: 0.05.

4. the application of the chlorine-doped zinc oxide nanorod prepared by the preparation method according to claim 1 is characterized in that: under the action of sound waves, the chlorine-doped zinc oxide nanorod catalyst promotes the photocatalytic degradation of RhB wastewater, and specifically comprises the following steps:

1) placing a chlorine-doped zinc oxide nanorod catalyst in a glass reactor, adding RhB wastewater, performing ultrasonic treatment to uniformly disperse the chlorine-doped zinc oxide nanorod catalyst in the RhB wastewater, and placing the reactor in the dark for dark adsorption for 30 minutes under stirring; 2) Fixing the reactor in a frequency-controllable sound wave vibration field, applying a xenon lamp light source above the reactor, wherein the power is 300W, and the wavelength is 200-700 nm; applying sound vibration below the reactor, controlling the sound frequency at 27-40 kHz, and opening circulating water all the time to keep the temperature of the reactor stable at 25 ℃ and finishing the reaction after 25 min.

5. Use according to claim 4, characterized in that: the concentration of the chlorine-doped zinc oxide nanorod catalyst in the glass reactor in the step 1) is 0.2 mg/ml.

Technical Field

The invention belongs to the technical field of photo-acoustic concerted catalysis, and particularly relates to preparation and application of a chlorine-doped zinc oxide nanorod.

Background

The contemporary world is facing environmental pollution due to rapid global industrialization leading to deterioration of water, air and soil quality due to accumulated organic and inorganic toxic compounds. These toxic compounds have hazardous properties that affect the ecosystem and thus human health. For this reason, remediation of contaminated water, air and soil is essential to improve human survival. Among various environmental remediation methods, the degradation of contaminants by photocatalytic semiconductor materials has been considered as a promising green technology for environmental remediation.

During the photocatalytic reaction, the host of photon-generated carriers is only two types: the complex conversion is thermal and other ineffective energy sources or participates in surface reaction, and the latter is an ideal energy conversion mode. Only when the photo-generated carriers smoothly migrate to the surface of the catalyst and act with the electron donor (acceptor) adsorbed on the surface of the catalyst, the ideal photo-catalytic oxidation (reduction) reaction can occur. In the above process, the separation and migration process of the photon-generated carriers is an intermediate link connecting the semiconductor light excitation and the surface reaction behavior. The improvement of the carrier separation efficiency of the semiconductor catalyst and the acceleration of the interface charge transfer are key scientific problems to be solved for constructing high-efficiency photocatalytic materials and are also the research frontier in the current international photocatalytic field.

Recently, attention has been focused on the use of ferroelectric and piezoelectric materials in photocatalytic technology. When a piezoelectric material is used, the built-in electric field generated by the piezoelectric material under force helps the charge separation. In the photocatalysis and piezoelectric composite materials reported at home and abroad, zinc oxide is widely reported as a star material, but the catalytic efficiency of the zinc oxide needs to be improved, the preparation process is complex, the yield is low, and the industrial production requirements cannot be met.

The invention discloses a new material with better piezoelectric property, which can promote the degradation of photocatalytic dye under the simultaneous action of sound wave and light, and the performance of the new material for catalyzing and degrading polluted wastewater is obviously superior to the action of zinc oxide by independent light or independent sound wave. The material can realize double capture of light energy and mechanical energy, and carry out polluted wastewater degradation under the synergistic drive of sound waves and light waves.

Disclosure of Invention

The invention aims to provide preparation and application of a chlorine-doped zinc oxide nanorod, which combines the photocatalytic property and the piezoelectric property of a material, realizes the auxiliary photocatalytic degradation of polluted wastewater under the action of sound waves, and improves the degradation rate by times.

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

preparation and application of a chlorine-doped zinc oxide nanorod, wherein the crystal belongs to a non-centrosymmetric hexagonal wurtzite structure; the length of the chlorine-doped zinc oxide nano rod is 0.5mm-1mm, and the diameter is 30nm-60 nm.

The preparation method of the piezoelectric catalyst is characterized in that zinc stearate is used as a zinc source, potassium hydroxide is used as an alkali source, zinc chloride is used as a chlorine source, methanol is used as a reaction solvent, and the chlorine-doped zinc oxide nanorod is prepared by an alcohol thermal method. The method specifically comprises the following steps:

(1) the molar ratio of the raw materials is 1: 1, respectively weighing zinc stearate and potassium hydroxide, respectively dissolving the zinc stearate and the potassium hydroxide in methanol, and stirring the solution at normal temperature to prepare alcoholic solutions of two reactants;

(2) slowly mixing the alcoholic solutions of the two reactants prepared in the step (1), stirring for 30 min while mixing, and then weighing the mixture of potassium hydroxide and zinc chloride according to a molar ratio of 1: adding 0.05 part of zinc chloride into the mixed solution, continuously stirring for 30 min to uniformly mix the mixed solution, and transferring the reaction solution into a polytetrafluoroethylene reaction kettle, wherein the solvothermal reaction temperature is 100-200 ℃, and the solvothermal time is 24-72 h;

(3) after the reaction is finished, washing the sample by using ethanol and deionized water, and drying at 60 ℃ for 12 h to prepare the chlorine-doped zinc oxide nano rod.

The application comprises the following steps: under the action of sound waves, the chlorine-doped zinc oxide nanorod catalyst promotes the photocatalytic degradation of RhB wastewater, and specifically comprises the following steps:

1) placing a chlorine-doped zinc oxide nanorod catalyst in a glass reactor, adding RhB wastewater, performing ultrasonic treatment to uniformly disperse the chlorine-doped zinc oxide nanorod catalyst in the RhB wastewater, and placing the reactor in the dark for dark adsorption for 30 minutes under stirring;

2) fixing the reactor in a frequency-controllable sound wave vibration field, applying a xenon lamp light source above the reactor, wherein the power is 300W, and the wavelength is 200-700 nm; the sound vibration is applied below, the sound frequency is controlled between 27 and 40 kHz, and the circulating water is always opened to keep the temperature of the reactor stable at 25 ℃. Samples were taken every 5min and the reaction was stopped after 25 min.

The concentration of the chlorine-doped zinc oxide nanorod catalyst in the glass reactor in the step 1) is 0.2 mg/ml.

The invention has the following remarkable advantages:

(1) the chlorine-doped zinc oxide catalyst adopted by the invention has a crystal structure which belongs to a non-centrosymmetric hexagonal wurtzite structure, is simple in preparation method and is suitable for industrial production;

(2) compared with a non-doped zinc oxide nano rod, the obtained chlorine-doped zinc oxide catalyst has higher piezoelectric performance, so that the capture and conversion of sound energy are facilitated;

(3) the obtained chlorine-doped zinc oxide can assist in photocatalytic degradation of dye under the action of sound waves, wherein the photocatalytic degradation rate can reach 0.02315 min in an ultrasonic field of 40 kHz^-1And the degradation rate of the zinc oxide under the same conditions is 0.0151 min^-1The degradation rate is 1.5 times of the photocatalytic wastewater degradation rate of zinc oxide under the assistance of sound waves and 4.9 times of the single photocatalytic degradation rate of chlorine-doped zinc oxide, so that the chlorine-doped zinc oxide can be seen in the wastewaterThe performance in terms of treatment is obviously superior to that of the zinc oxide catalyst.

(4) The catalyst prepared by the invention not only can enrich mechanical energy in natural environment, but also can provide a new path for degrading photocatalytic polluted wastewater, and realizes dual capture of light energy and mechanical energy.

Drawings

FIG. 1 is an X-ray diffraction pattern of zinc oxide and chlorine-doped zinc oxide nanorods;

FIG. 2 is a zinc oxide field emission scanning electron microscope image;

FIG. 3 is a field emission scanning electron microscope image of a chlorine-doped zinc oxide nanorod;

figure 4 is a graph of the degradation rate of zinc oxide and chlorine doped zinc oxide nanorods dye.

Detailed Description

In order to make the present invention more comprehensible, the technical solutions of the present invention are further described below with reference to specific embodiments, but the present invention is not limited thereto.