阅读说明：本技术 一种掺杂的ZnO材料及其制备方法与丙酮传感器 (Doped ZnO material and preparation method thereof and acetone sensor ) 是由 杜宇 黄金玉 于 2019-09-29 设计创作，主要内容包括：本发明公开一种掺杂的ZnO材料及其制备方法与丙酮传感器,其中,方法包括步骤：将锌源与水混合,搅拌直至锌源溶解,之后加入碱源和无水乙醇,搅拌直至得到澄清溶液；向澄清溶液中加入可溶性金源或者可溶性钯源,将得到的溶液转移至微波反应仪中进行反应；反应结束后依次进行冷却、洗涤、干燥及退火,得到Au或Pd掺杂的ZnO材料。本发明采用一步微波水热法直接将Au或者Pd掺杂到ZnO材料中,制备操作容易,过程简单。与普通物理掺杂相比,采用本发明方法掺杂剂分散的更均匀,合成出的复合材料中各组分可以实现在分子层面上接触。本发明中的基于Au或Pd掺杂的ZnO材料的丙酮传感器对低浓度的丙酮展现出较好的气敏特性。(The invention discloses a doped ZnO material, a preparation method thereof and an acetone sensor, wherein the method comprises the following steps: mixing a zinc source with water, stirring until the zinc source is dissolved, then adding an alkali source and absolute ethyl alcohol, and stirring until a clear solution is obtained; adding a soluble gold source or a soluble palladium source into the clarified solution, and transferring the obtained solution into a microwave reactor for reaction; and after the reaction is finished, sequentially cooling, washing, drying and annealing to obtain the Au or Pd doped ZnO material. The invention adopts a one-step microwave hydrothermal method to directly dope Au or Pd into the ZnO material, and has the advantages of easy preparation operation and simple process. Compared with common physical doping, the method of the invention has the advantages that the dopant is dispersed more uniformly, and the components in the synthesized composite material can be contacted on the molecular level. The acetone sensor based on the Au or Pd doped ZnO material shows better gas-sensitive property to low-concentration acetone.)

1. A preparation method of a doped ZnO material is characterized by comprising the following steps:

mixing a zinc source with water, stirring until the zinc source is dissolved, then adding an alkali source and absolute ethyl alcohol, and stirring until a clear solution is obtained;

adding a soluble gold source or a soluble palladium source into the clarified solution, and transferring the obtained solution into a microwave reactor for reaction;

and after the reaction is finished, sequentially cooling, washing, drying and annealing to obtain the Au or Pd doped ZnO material.

2. The method for preparing the doped ZnO material according to claim 1, wherein the reaction temperature is 140-180 ℃; and/or the reaction time is 30-60 min.

3. The preparation method of the doped ZnO material according to claim 1, wherein the annealing temperature is 400-550 ℃; and/or the annealing time is 2-5 h.

4. The method for preparing the doped ZnO material according to claim 1, wherein the molar ratio of the zinc source, the alkali source and the soluble gold source is 1: 22-44: 0-0.077; or

The molar ratio of the zinc source, the alkali source and the soluble palladium source is 1: 22-44: 0-0.088.

5. The method for preparing doped ZnO material of claim 1, wherein the zinc source is selected from one or more of zinc acetate, zinc chloride and zinc nitrate; and/or

The alkali source is selected from one of potassium hydroxide and sodium hydroxide.

6. The method of claim 1, wherein the soluble gold source is one or more of chloroauric acid, gold nitrate, gold chloride, and gold acetate.

7. The method of claim 1, wherein the soluble palladium source is one or more of palladium nitrate, palladium chloride, and palladium sulfate.

8. A doped ZnO material, characterised in that it has been produced by a process according to any one of claims 1 to 7.

9. The doped ZnO material of claim 8, wherein the Au accounts for 0-6% of the doped ZnO material by mass; or

The Pd accounts for 0-7% of the mass percent of the doped ZnO material.

10. An acetone sensor, comprising a ceramic tube, wherein the surface of the ceramic tube is coated with a doped ZnO material prepared by the method of any one of claims 1 to 7; and/or

The surface of the ceramic tube is coated with the doped ZnO material of any of claims 8-9.

Technical Field

The invention relates to the field of gas sensors, in particular to a doped ZnO material, a preparation method thereof and an acetone sensor.

Background

The current primary method of blood glucose detection and monitoring is invasive, i.e., drawing blood by needle-pricking a fingertip or a vein. Some patients need to prick their fingers to obtain blood data even seven times a day, which causes pain and inconvenience to the patients. Meanwhile, the test paper is used throughout the year, so that the family of the patient is subjected to great economic pressure. Recent studies have shown that acetone in breath can be an important marker for monitoring diabetes. However, most of the existing detection means of acetone in breath are large-scale instruments such as chromatography, mass spectrometry, spectrometers and the like, and the detection means needs to be operated by professional personnel and is expensive, so that much inconvenience is brought to detection.

At present, ZnO sensors for detecting acetone have been researched and reported, but the sensors have the defects of high working temperature, poor selectivity, high detection concentration, poor moisture resistance, slow response-recovery speed and the like, and are not suitable for being used as breath marker sensors. Some researchers have proved that doping of noble metals Au and Pd can effectively improve the gas-sensitive property of ZnO acetone, but the research of realizing ultralow concentration (several-dozens of ppb) acetone, low temperature, high selection, moisture resistance and rapid detection is still challenging.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

In view of the above-mentioned shortcomings of the prior art, the present invention aims to provide a doped ZnO material, a method for preparing the same, and an acetone sensor, which are used to solve the problems of high operating temperature, poor selectivity, high detection concentration, poor moisture resistance, slow response-recovery rate, etc. of the existing sensors.

The technical scheme of the invention is as follows:

a preparation method of a doped ZnO material comprises the following steps:

mixing a zinc source with water, stirring until the zinc source is dissolved, then adding an alkali source and absolute ethyl alcohol, and stirring until a clear solution is obtained;

adding a soluble gold source or a soluble palladium source into the clarified solution, and transferring the obtained solution into a microwave reactor for reaction;

and after the reaction is finished, sequentially cooling, washing, drying and annealing to obtain the Au or Pd doped ZnO material.

Further, the reaction temperature is 140-180 ℃; and/or the reaction time is 30-60 min.

Further, the annealing temperature is 400-550 ℃; and/or the annealing time is 2-5 h.

Further, the molar ratio of the zinc source to the alkali source to the soluble gold source is 1: 22-44: 0-0.077; or

The molar ratio of the zinc source, the alkali source and the soluble palladium source is 1: 22-44: 0-0.088.

Further, the zinc source is selected from one or more of zinc acetate, zinc chloride and zinc nitrate; and/or

The alkali source is selected from one of potassium hydroxide and sodium hydroxide.

Further, the soluble gold source is one or more of chloroauric acid, gold nitrate, gold chloride and gold acetate.

Further, the soluble palladium source is one or more of palladium nitrate, palladium chloride and palladium sulfate.

The doped ZnO material is prepared by the preparation method of the doped ZnO material.

Further, based on the doped ZnO material, the Au accounts for 0-6% of the doped ZnO material by mass; or

The Pd accounts for 0-7% of the mass percent of the doped ZnO material.

An acetone sensor comprises a ceramic tube, wherein the surface of the ceramic tube is coated with a doped ZnO material prepared by the method; and/or

The surface of the ceramic tube is coated with the doped ZnO material.

Has the advantages that: the invention adopts a one-step microwave hydrothermal method to directly dope Au or Pd into the ZnO material, and has the advantages of easy preparation operation and simple process. Compared with common physical doping, the method of the invention has the advantages that the dopant is dispersed more uniformly, and the components in the synthesized composite material can be contacted on the molecular level. The acetone sensor based on the Au or Pd doped ZnO material shows better gas-sensitive property to low-concentration acetone, and has the advantages of low working temperature, high sensitivity, wide detection range (5ppb-100ppm), excellent selectivity and quick response speed.

Drawings

FIG. 1: a) the X-ray diffraction patterns of Au/ZnO, Pd/ZnO and undoped ZnO materials provided by the embodiment are shown in (b-e) a scanning electron microscope image, a transmission electron microscope image, a high-resolution transmission electron microscope image and a selected area electron diffraction image of undoped ZnO respectively, f) a Pd/ZnO transmission electron microscope image, (g-i) a transmission electron microscope image, a high-resolution transmission electron microscope image and a selected area electron diffraction image of Au/ZnO respectively, and (j-k) X-ray photoelectron spectra of Au/ZnO and Pd/ZnO respectively.

FIG. 2: a) the sensitivity curves of the Au/ZnO and Pd/ZnO and undoped ZnO materials provided for the examples at different operating temperatures for 100ppm acetone gas, b) the selectivities of Au/ZnO and Pd/ZnO and undoped ZnO for different gases, c) the sensitivities of Au/ZnO and Pd/ZnO and undoped ZnO for different concentrations of acetone gas (low concentration), d) the sensitivities of Au/ZnO and Pd/ZnO and undoped ZnO for different concentrations of acetone gas (high concentration).

Detailed Description

The invention provides a doped ZnO material, a preparation method thereof and an acetone sensor, and the invention is further described in detail below in order to make the purpose, technical scheme and effect of the invention clearer and more clear and definite. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment of the invention provides a preparation method of a doped ZnO material, which comprises the following steps:

s10, mixing a zinc source with water, stirring until the zinc source is dissolved, then adding an alkali source and absolute ethyl alcohol, and stirring until a clear solution is obtained;

s20, adding a soluble gold source or a soluble palladium source into the clear solution, and transferring the obtained solution into a microwave reactor for reaction;

and S30, after the reaction is finished, cooling, washing, drying and annealing are sequentially carried out, so that the Au or Pd doped ZnO material is obtained.