Surface acoustic wave hydrogen sensor based on synergistic effect of load mass and conductivity and preparation method thereof

Abstract

The invention discloses a surface acoustic wave hydrogen sensor based on the synergistic effect of load mass and conductivity and a preparation method thereof. The sensor comprises a LiNbO3 piezoelectric substrate, interdigital transducers, a sensitive layer and an external circuit, wherein the sensitive layer is arranged in the middle of the surface of the LiNbO3 piezoelectric substrate; the twoends of the sensitive layer are each provided with one interdigital transducer, wherein one interdigital transducer excites Rayleigh waves on the LiNbO3 piezoelectric substrate through the inverse piezoelectric effect, and the Rayleigh waves are transmitted to the other interdigital transducer through the surface of the LiNbO3 piezoelectric substrate and converted into electric signals again through the piezoelectric effect; and the sensitive layer is a Pt / RGO composite sensitive layer, wherein Pt is used as a catalyst. According to the invention, Pt / RGO is used as the sensitive layer, hydrogen is adsorbed to cause increase of load mass and change of conductivity to generate a synergistic effect to jointly realize high-sensitivity sensing of hydrogen, the sensor can be used for detecting trace hydrogen at room temperature, and the sensitivity of the sensor to hydrogen is improved.

Description

technical field [0001] The invention relates to a surface acoustic wave hydrogen sensor based on the synergistic effect of load mass and electrical conductivity and a preparation method thereof, belonging to the precision sensor technology. Background technique [0002] Ultrasonic sensors are mainly composed of a piezoelectric substrate and a sensitive layer deposited on the substrate. Due to its advantages of high sensitivity, low detection limit, small size, low power consumption, and high integration, it has been widely studied in the field of gas sensing. As a clean and renewable energy, hydrogen is flammable, explosive and difficult to store. The detection of trace hydrogen is a very important topic. [0003] The response of most current hydrogen sensors to hydrogen is based on the adsorption of hydrogen by the sensitive layer, but these sensors are easily affected by the operating temperature. due to H 2 The adsorption force is weak, the quality is low, and the sensi...

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Problems solved by technology

[0010] Purpose of the invention: In order to solve the problem that the sensitive layer of the hydrogen sensor has weak adsorption capacity for hydrogen at normal temperature and low sensitivity, so that it cannot adapt to the detection of trace hydrogen at normal temperature, the present invention provides a synergistic method based on load mass and conductivity The effective surface acoustic wave hydrogen sensor and its preparation method use the Pt / RGO composite sensitive layer to adsorb hydrogen, and the increase in the load mass and the increase in conductivity have a synergistic effect on the center frequency shift, greatly improving the sensitivity to hydrogen, and can be used at room temperature Detection of trace amounts of hydrogen

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