Cobalt titanate gas sensitive material with high sensitivity to low concentration ethanol and preparation method thereof

Abstract

A cobalt titanate gas-sensing material with high sensitivity to low-concentration ethanol and a preparation method thereof. The particle size of the gas-sensing material is 25-100nm, and the three-dimensional structure formed by powder accumulation has mesopores, and the average pore diameter of the mesopores is 30-40nm. Pore ​​volume 0.1~0.3cm 3 / g, specific surface area 5~21m 2 / g; The preparation method is: (1) using absolute ethanol as a solvent, or a mixture of ethylene glycol and absolute ethanol as a solvent; (2) adding tetrabutyl titanate and cobalt nitrate to the solvent, stirring Mix to form a red clear mixed solution; (3) carry out solvothermal reaction at 150-220°C, and centrifuge to separate the solid phase; (4) roast at 600-750°C after drying. The product prepared by the invention has high sensitivity to low-concentration ethanol gas, short response time, simple preparation process and low cost, and is suitable for popularization and application.

Description

technical field [0001] The invention belongs to the technical field of metal oxide semiconductor gas-sensitive materials, and in particular relates to a cobalt titanate gas-sensitive material with high sensitivity to low-concentration ethanol and a preparation method thereof. Background technique [0002] With the improvement of people's quality of life, health and safety issues are particularly important; ethanol is the main component of various alcohols, and it is flammable. It can cause combustion and explosion when exposed to open flames and high temperatures. Great health and safety hazards; cobalt titanate is a P-type semiconductor oxide with good chemical stability and low cost, and is widely used in the detection of ethanol gas; however, it has poor sensitivity to low-concentration ethanol gas, narrow operating temperature range, Long response recovery time has become a major obstacle in its practical application; since the sensitivity of the sensor depends on factor...

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Problems solved by technology

[0003] The preparation methods of traditional cobalt titanate gas-sensing materials mainly include magnetron sputtering method, sol-gel method, hydrothermal method, etc. These methods have disadvantages such as high energy consumption, long time consumption, and expensive raw materials, and the prepared titanate The sensitivity of cobalt gas-sensing materials is not high enough, and the working temperature range needs to be further expanded; in order to improve the sensitivity of cobalt titanate gas-sensing materials, researchers have done a lot of work, such as ion doping, compounding with other metal oxides, and developing new materials; Doping cobalt titanate or compounding it with other substances complicates the preparation process, and the process parameters are difficult to control; it is necessary to fundamentally solve the poor sensitivity and response recovery of current cobalt titanate gas-sensitive materials. It is not fast enough and the working temperature range is narrow, and it is necessary to strengthen the development and research of new gas-sensitive materials

[0004] Chinese patent CN201610583835.3 discloses a new type of CoTiO 3 The preparation method and application of gas-sensitive materials, the method uses cobalt nitrate hexahydrate and tetra-n-butyl titanate as initial raw materials, ethylene glycol methyl ether as solvent, citric acid as complexing agent, and CoTiO is prepared by sol-gel method 3 Gas-sensitive materials; the preparation process of this method is complicated, and the obtained sol needs to be left for a long time, secondary drying and secondary calcination treatment, high energy consumption, long time consumption, easy to pollute the environment during the preparation process, and the obtained CoTiO 3 The response time of gas-sensing materials to ethanol gas is longer, which takes 15s; therefore, the key to research is to prepare gas-sensing materials with high sensitivity, fast response and wide operating temperature range by simple methods

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