Semiconductor-based combustible gas sensors for the petrochemical industry: a review

Semiconductor-based gas sensors offer a promising approach for monitoring and early warning of combustible gases in the petrochemical industry, owing to their low detection limits, high cost-effectiveness, and suitability for large-scale deployment. However, compared with established mainstream technologies, such as catalytic combustion and optical approaches, semiconductor-based combustible gas sensors still require more systematic and deeper research to become a leading solution in practical engineering applications. In this review of semiconductor-based combustible gas sensors, we first outline the main sensing materials used in these gas sensors, including metal oxide semiconductors (MOS), two-dimensional (2D) semiconductors, and carbon nanotubes (CNTs), and then describe their sensing mechanisms, including the surface-adsorbed oxygen ion mechanism and the charge transfer mechanism. Subsequently, we discuss key gas sensing performance parameters, including sensitivity, selectivity, response and recovery times, linear detection range, and stability. Furthermore, based on these parameters, we systematically summarize the main strategies and recent advances aimed at overcoming current performance limitations. They are categorized into nine types, namely, morphology engineering, defect engineering, composite materials, heterojunctions, noble metal modification, gas identification algorithms, molecular sieves, gas sensor arrays, and light illumination. Finally, in view of the current research landscape, we highlight perspectives on future research for semiconductor-based combustible gas sensors in the petrochemical industry.