Double layer structural photocatalytic formaldehyde sensor and preparation method thereof

A formaldehyde sensor, double-layer structure technology, applied in the direction of material resistance, can solve problems such as unsuitable application, and achieve the effect of improving sensitivity and good application prospects

Inactive Publication Date: 2015-09-09
PEKING UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, although this technology reduces the detection limit of formaldehyde to 0.5ppm, it is still nearly an order of magnitude higher than the safe concentration (0.06ppm), which is not suitable for practical application in the living environment.

Method used

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  • Double layer structural photocatalytic formaldehyde sensor and preparation method thereof
  • Double layer structural photocatalytic formaldehyde sensor and preparation method thereof
  • Double layer structural photocatalytic formaldehyde sensor and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Step 1: Synthesis of ZnO nanoparticles

[0035] 10.77g ZnSO 4 ·7H 2 O (375 mmol) was dissolved in 25 mL deionized water. The solution was added dropwise to 50mL100g / L (1.36mmol / L) NH 4 HCO 3The solution was stirred for 1 h in a water bath at 40°C. The supernatant was removed, and the precipitate was washed three times with 15 mL of deionized water each time, and then the precipitate was dried at 80 °C for 12 h and at 120 °C for 2 h. After baking, the samples were calcined in a muffle furnace at 500 °C for 2 h.

[0036] Step 2: Addition of cadmium element

[0037] Weigh 0.4 g of pre-prepared ZnO nanoparticles and disperse them in 60 mL of cadmium salt solution (3CdSO 4 ·8H 2 (00.019g), the solution was stirred at 80°C and the solvent was evaporated to dryness, then the precipitate was dried at 80°C for 12h and at 120°C for 2h. After this the precipitate was calcined at 450°C.

[0038] Step 3: Synthesis of porous silica nanoparticles

[0039] 6.4 mL of water, 0...

Embodiment 2

[0050] The method of step 2 in embodiment 1 can be replaced by following scheme:

[0051] Step 2: Addition of cadmium element

[0052] Weigh 0.4 g of pre-prepared ZnO nanoparticles and disperse them in 60 mL of cadmium salt solution (3CdSO 4 ·8H 2 (00.019g), the solution was stirred at 70°C and the solvent was evaporated to dryness, then the precipitate was dried at 70°C for 10h and at 110°C for 1h. After this the precipitate was calcined at 400°C.

Embodiment 3

[0054] The method of step 2 in embodiment 1 can be replaced by following scheme:

[0055] Step 2: Addition of cadmium element

[0056] Weigh 0.4 g of pre-prepared ZnO nanoparticles and disperse them in 60 mL of cadmium salt solution (3CdSO 4 ·8H 2 (00.019g), the solution was stirred at 90°C and the solvent was evaporated to dryness, then the precipitate was dried at 90°C for 14h and at 130°C for 3h. After this the precipitate was calcined at 500°C.

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Abstract

The invention relates to a double layer structural photocatalytic formaldehyde sensor and a preparation method thereof. The formaldehyde sensor includes a light source, an electrode, a formaldehyde sensitive material layer and a formaldehyde adsorption material layer, the electrode is covered with the formaldehyde sensitive material layer, the formaldehyde sensitive material layer is covered with the formaldehyde adsorption material layer. Preferably, the formaldehyde sensitive material layer is cadmium doped zinc oxide nanoparticles, and the formaldehyde adsorption material layer is porous silica nanoparticles. The light source is an ultraviolet light source, and irradiates to a double layer structure area. During detecting of formaldehyde pollutants in air, the formaldehyde adsorption material can increase concentration of the formaldehyde on the surface of the formaldehyde sensitive material layer so as to increase the sensor sensitivity, and the low concentration formaldehyde sensitivity can be improved. The double layer structural photocatalytic formaldehyde sensor greatly improves the low concentration formaldehyde sensitivity of the cadmium doped zinc oxide formaldehyde sensor, the progress in the practical application of the sensor can be and promoted, the double layer structural photocatalytic formaldehyde sensor has a good application prospect.

Description

technical field [0001] The invention belongs to the technical fields of formaldehyde gas monitoring and formaldehyde sensors, and in particular relates to a double-layer structure photocatalytic formaldehyde sensor and a preparation method thereof. Background technique [0002] Long-term exposure to formaldehyde gas exceeding the safe concentration limit is very harmful to human health, which may cause burning sensation in the eyes and throat, difficulty in breathing, and even fatal diseases such as nasal cancer, myelogenous leukemia, etc. At present, formaldehyde pollution is still very serious in China. Nearly 70% of newly renovated houses are plagued by formaldehyde pollution. Therefore, the most worrying indoor pollutant gas in China is formaldehyde. [0003] For air quality products, sensor technology is very important, because if consumers are not sure about the true role of air quality products, then they will have doubts about related products. The current commercia...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N27/04
Inventor 常兴华刘宇郑捷李星国
Owner PEKING UNIV
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