A comprehensive review of gas-phase sulfur compound detection and measurement techniques

This study investigates detecting and measuring sulfur compounds techniques in the gas phase (SO 2 , H 2 S). These methods include conductive polymer, acoustic, carbon nanotubes, semiconductor-based metal oxide, and optical methods, each with advantages and limitations. Sensor parameters such as selectivity and sensitivity, power consumption, response and recovery time, operating temperature, detection limit, portability, etc. were investigated. In addition, operating conditions and the materials used in the construction of the sensors were investigated as well. In particular, metal oxide semiconductor materials have been considered the main candidates for gas detection since the first chemical-resistant gas sensors were built. Various metal oxides have been exploited for the evolution of gas sensing in academic and commercial platforms. The results showed that conductive polymer composite is a promising material to develop an effective gas sensor device, demonstrating the interactions between the material and the gas under ambient conditions. It produces a readout signal at room temperature without the need for a microheater. Optical and acoustic wave methods are superior to other methods due to features such as high sensitivity (ppb ranges), fast response time, easy operation in the absence of oxygen, not being affected by electromagnetic interference, and a very wide monitoring area, but they face problems such as miniaturization and high manufacturing costs.