Zinc oxide-based sensing gas-sensitive composite material as well as preparation method and application thereof

Abstract

The invention discloses a zinc oxide-based sensing gas-sensitive composite material as well as a preparation method and application thereof. The preparation method comprises the following steps of: loading nano-copper / silver particles on the surface of a zinc oxide nano-agglomerate by a solution reduction method, and preparing a zinc oxide composite material simultaneously loaded with palladium and nano-copper / silver by utilizing a nano-copper / silver reduction effect; and coating the surface of the zinc oxide composite material with a zinc-containing ZIF layer through in-situ growth, and / or coating the surface of the composite material with a microporous molecular sieve layer through a coating method, so as to form the zinc oxide-based sensing gas-sensitive composite material. According to the invention, high-sensitivity, fast-response and high-selectivity sensing detection on methane can be realized, and a new way is provided for methane sensing in industries such as coal mines and natural gas.

Description

technical field [0001] The invention relates to the technical field of new chemical materials, in particular to a zinc oxide-based sensing gas-sensing composite material and a preparation method and application thereof. Background technique [0002] Methane (CH 4 ) is the main component of natural gas and coal mine gas. It is also a flammable and explosive gas, and the explosion limit in air is 5-15%. Rapid and accurate monitoring of methane concentration is the key to ensuring the safe production of natural gas and coal mines. There are three main types of methane sensors: catalytic combustion, infrared and semiconductor oxides. [0003] The catalytic combustion methane sensor mainly uses a catalytic combustion gas sensor for detection. The working principle is that methane burns flamelessly on the surface of a platinum catalyst, and the temperature rise causes a change in the resistance of the platinum wire. However, there are problems with this type of sensor: 1. The w...

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Problems solved by technology

However, there are problems with this type of sensor: 1. The working temperature is high (650-800°C), and it is more dangerous to use in an inflammable and explosive atmosphere

2. The stability is poor, the catalyst is prone to carbon deposition and deactivation, and needs to be re-calibrated within 7-14 days

3. Poor selectivity, responsive to other reducing gases (such as carbon monoxide, hydrogen sulfide, sulfur dioxide, etc.)

[0006] However, most of the reported work on methane sensing with zinc oxide-based materials focuses on the detection of a single methane system, and seldom involves the selective detection of methane under the coexistence of multi-component gases.