Prepapation And Characterization Of Graphene-Based Gas Sensor Array

Discovered in 2004, graphene has become a research hotspot due to its unique electrical, physical, chemical and mechanical properties. Therefore, mixing graphene and polymer or metallic oxide could effectively improve the response of the gas sensors.However, because a single gas sensor exhibits cross-sensitivity, the gas sensor cannot be applied well to environment with multiple unknown gases Gas sensor arrays combined with pattern recognition technology improve the sensor selection and measurement precision.This paper studies the fabrication, performance and sensibility of the gas sensor array based on graphene. As for the sensor units, the sensing response, the repeatability,the long-term stability and the selectivity are analyzed, respectively. Combined with the surface and section morphology of the sensing films observed by scanning electron microscope, the specific response mechanisms are discussed preliminary. And then,potential application of RGO in the gas sensor array is studied.This article is composed of three parts:（1） The sensor arrays were prepared, and their preparation parameters are optimized.（2） For NO₂ detection, four kinds of sensitive materials, including SnO₂/RGO,ZnO/RGO, PVP/RGO and PPY/RGO, are sprayed on four units of sensor array separately by mask method. Besides, the response-recovery properties from sensor array to NO₂ are tested. Results indicate that SnO₂/RGO presents a maximum sensitivity to NO₂. For further study of gas sensitivity of SnO₂/RGO based gas sensor, four kinds of SnO₂/RGO with different mass fraction of SnO₂ are prepared. And their response-recovery property, repeatability gas selectivity and long-term stability to NO₂ are tested. Results show that composite with proper SnO₂ displays better sensitivity,repeatability and best selectivity for NO₂, except for the long-term stability.（3） For NH₃ detection, four kinds of sensitive materials, including SnO₂/RGO,ZnO-（SnO₂ /RGO）, PVP/RGO and PPY/RGO, are sprayed on four units of sensor array respectively by mask method. Besides, the response-recovery properties of the sensor array to NH₃ are tested. Results indicate that ZnO-（SnO₂/RGO） has the maximum sensitivity for NH₃. For further study of gas sensitivity for ZnO-（SnO₂ /RGO） based gassensor, four kinds of stratified films with different mass fraction are prepared. And their response-recovery property, repeatability, gases selectivity and long-term stability to NH₃ are tested respectively. Results show that stratified film with appropriate RGO holds higher sensitivity, repeatability and best selectivity of NH₃.